Currently, reserves replacement issues are of particular interest for Tatneft and generally for the Republic of Tatarstan. Reserves replacement due to discovery of new fields in conventional oil plays does not enable 100% replenishment of current oil production. For intrinsic geological reasons, newly discovered fields are small and very small. In light of the above, following US “shale revolution” the Company has turned its focus toward the Domanic deposits (Zavozhskian through Sargaevskian), widely spread across the Republic of Tatarstan and generally in the Volga-Ural petroleum province. Since 2013, Tatneft has been conducting extensive research of domanikites. To date, a series of studies on refinement of geological structure of the Domanic sediments has been performed, petroleum potential has been determined, a series of scientific research and issue-related studies has been conducted. Each year, technologies and methods for stimulation of poor-quality reservoirs are developed and implemented,   in that number horizontal drilling technologies, non-damaging acid treatments and multi-zone fracturing. The paper considers the lessons learned from the study and pilot oil production operations conducted by Tatneft in the Domanic sediments. Results of scientific research of the Domanic sediments conducted in cooperation with Moscow State University, Oil and Gas Institute of the Russian Academy of Sciences, All-Russian Geological Research and Development Oil Institute, Kazan (Volga region) Federal University, and Arbuzov Institute of Organic and Physical Chemistry are provided. The first-priority production targets are the Domanic deposits of the Semilukskian/Mendymskian horizons. These are tight low-permeability rocks, containing considerable amounts of organic matter, and   exhibiting both oil-producing and petroleum containment properties. Oil production from Domanic deposits requires stimulation of productive formations. Well stimulation techniques applied in promising intervals identified from extended well logging data comprise massive bottom-hole treatments, hydrochloric acid injection, hydraulic fracturing and acid fracturing. The paper reviews the details of field trials (in intervals with various petroleum mobility characteristics): well selection workflow is provided; conducted field operations are highlighted as well as success rate by production targets. Necessity and challenges of polygon creation are discussed. Prospects and suggested way forward on the development of Domanic deposits are summarized.

 

1Minnikhanov R.N., Maganov N.U., Khisamov R.S., On creation of research and testing facilities to promote study of nonconventional oil reserves in Tatarstan (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 8, pp. 60­–62.

The method of dynamic formation stimulation using powder generator of pressure was tested on the Tashliyarskaya area of Romashkinskoye field. Well No. 14414 was selected for the field test. All in all, six consecutive treatments at three-hours interval were made using sets comprising 3, 5, 7, 8, 8, 7 charges. To understand the in-situ process, short-period wave field was continuously monitored using a network of high-sensitivity three-component digital seismic stations. Good-quality seismic signals were recorded and mechanisms of seismic signals generation were determined. Generation of seismic signals is conditioned by shots in well and by response of the formation in the near-wellbore zone and adjacent rocks. Waves’ travel paths to observation stations were explained. The obtained data help to understand seismic events that take place after treatment operations have been completed, and to assess the duration of the desired effect. Sources of seismic signals in the productive interval against the casing-formation annulus and in the adjacent rocks were determined, as well as channels of seismic signals propagation. The paper presents the results of seismic observations following the dynamic formation stimulation and the analysis of post-processes. Seismic gathers of local earthquakes were studied, time of direct waves’ arrivals and seismic spectra were determined, changes in microseismic background level were analyzed. The results confirm the effectiveness of the technology of dynamic stimulation using in-hole shots to increase the reservoir permeability. To improve the technology, the project should be extended to other field areas. This will allow to optimize stimulation modes considering changes in the subsurface environment and to work out proper measurement methods to determine the criteria for stimulation termination in real-time mode.

References

1. Khisamov R.S., Gatiyatullin N.S., Kuz'min Yu.O. et al., Sovremennaya geodinamika i seysmichnost' yugo-vostoka Tatarstana (Modern geodynamics and seismicity of the south-eastern part of Tatarstan), Kazan': FEN Publ., 2012, 240 p.

2. Kaazik P.B., Kopnichev Yu.F., Nersesov I.L., Rakhmatullin M.Kh., Analysis of the fine structure of short-period seismic fields for a group of stations (In Russ.), Doklady AN SSSR, 1989, V. 308, no. 5, pp. 1090–1094.

3. Kaazik P.B., Kopnichev Yu.F., Nersesov I.L., Rakhmatullin M.Kh., Analysis of the fine structure of short-period seismic fields for a group of stations (In Russ.), Izvestiya AN SSSR. Seria Fizika Zemli, 1990, no. 4, pp. 38–49.

4. Bath M., Spectral analysis in geophysics, Elsevier, Amsterdam, 1974, 563 p.

5. Nersesov I.L., Kaazik P.B., Rakhmatullin M.Kh., Tregub F.S., About the possibility of searching for gas fields by spectral ratios of the amplitudes of the microseismic background (In Russ.), Doklady AN SSSR, 1990, V. 312, no. 5, pp. 1084–1086.

As soon as commercial production of extra-heavy oil reserves began, understanding of hydrogeological conditions of heavy oil reservoirs came to the fore. In Tatarstan, heavy oil accumulations are confined to the western slope of the South-Tatarian Arch and the eastern flank of the Melekess Depression. Most of the heavy oil reservoir has been found in the terrigenous Sheshminskian formation dated to the Ufimian age; few reservoirs have been found in the carbonate and in the carbonate-sandstone Kazanian, Sakmarian, and Asselian formations.

Hydrogeological conditions of heavy oil fields in different tectonic regions are discussed in this paper. Conditions of forming of subsurface waters are discussed, results of chemical analysis of waters of the so far most explored fields in the carbonate-sandstone Kazanian formation, the Ufimian sandstone Sheshminskian formation, and the Lower Permian carbonate Sakmarian and Asselian formations are presented. Hydrogeological conditions were studied using geological evidence and information collected during pilot production of heavy oil. We arrived at the conclusion that neither type of waters, nor mineralization depend on the stratigraphic confinement of aquifers; they are rather determined by the distance to heavy oil accumulations and the drainage relief. It is noteworthy that there is a marked difference between chemical compositions of waters of the fields in the western slope of the South-Tatarian Arch and the eastern flank of the Melekess Depression. Because of good connectivity, waters of the Carboniferous and Permian formations mix with each other. When water of a certain type interacts with hydrocarbons in presence of sulfate-reducing bacteria, waters of a quite different type appear in the internal waters of a heavy oil reservoir. To achieve optimal reservoir performance and to control environmental impact caused by the Company’s upstream activities it is very important to understand what causes changes of the chemical composition of waters.

References

1. Kubarev P.N., Aslyamov N.A., Petrova G.I. et al, Study of hydrogeological environment in heavy oil reservoirs developed by thermal method (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 7, pp. 49–52.

2. Gatiyatullin N.S., Peculiarity of spatial occurrence of Permian bitumens and more deep oil pools on the Tatarstan Republic territory (In Russ), Neftegazovaya geologiya. Teoriya i praktika, 2010, V. 5, no. 3, URL: http://www.ngtp.ru/rub/9/34_2010.pdf

3. Anisimov B.V., Gidrogeologicheskie osobennosti zaleganiya bitumnykh zalezhey v permskikh otlozheniyakh TASSR (Hydrogeological features of the occurrence of bitumen deposits in the Permian deposits of the TASSR), Collected papers “Prirodnye bitumy – dopolnitel'nyy istochnik uglevodorodnogo syr'ya” (Natural bitumens – an additional source of hydrocarbons), Proceedings of IGiRGI, 1984, pp. 136–142.

4. Khisamov R.S., Gatiyatullin R.N., Ibragimov R.L. et al, Gidrogeologicheskie usloviya mestorozhdeniy tyazhelykh vysokovyazkikh neftey i prirodnykh bitumov (Hydrogeological conditions of deposits of heavy highly viscous oils and natural bitumens), Kazan': Ikhlas Publ., 2016, 176 p.

This paper presents theoretical research of sidetracking process parameters affecting a profile liner passing through the hole, as well as allowable axial loading when running it to the setting depth to isolate a trouble zone. The highest number of troubles during sidetracking and horizontal sidetracking in the Romashkinskoye field (Tatarstan) is encountered in Kynovian mudstones having thickness up to 30 m. These troubles include rock sloughing, caving, hole shoulders at point where soft rock changes to Kynovian hard-rock deposits, as well as disastrous lost circulation zones. Isolation of such zones by LCM or cement squeezing is material intensive and time consuming, and in most cases these actions are unsuccessful. All these troubles become nearly unmanageable in high buildup and drop-off sections, or when adjusting the sidetrack direction and drilling a horizontal section due to specific operation of a bend motor resulting in numerous breakouts and shoulders, and due to small hole size. Sometimes profile liners that were run to isolate the trouble zones could not pass through such hole sections. The profile liner had to be run out of hole, the well was underreamed, and then the profile liner was run in hole again, which resulted in drilling time and cost growth. Based on research data and analysis of best practices in isolating trouble zones with profile liners, guidelines are provided to improve sidetracking process parameters, which will enable easy running of the profile liner to the setting depth, thus saving time and money.

References

1. Meling K.V., Akhmadishin F.F., Nasyrov A.L. et al., Isolation of lost circulation zones in sidetracks with expandable profile liner (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2009, no. 11, pp. 107-109.

2. Akhmadishin F.F., K Meling.V., Mukhametshin A.A. et al., Isolation of Kynovskian shales with expandable profile liner of PBI–144/130 type (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2010, no. 7, pp. 16-17.

3. Ratent SU1070989 RF, MPK E 21 V 29/00, Profiled overlapping appliance, Inventors: Meling K.V., Abdrakhmanov G.S., Yusupov I.G., Safonov Yu.A.

4. Patent no. 2172387 RF, MPK E 21 V 29/10, Shoe for installation of shaped shutoff devices in wells, Inventors: Yusupov I.G., Abdrakhmanov G.S., Farkhutdinov R.G., Khamit'yanov N.Kh., Meling K.V., Kashapov I.K., Mukhametshin A.A., Vil'danov N.N., Nasyrov A.L.

5. Patent no. 2483187 RF, MPK E 21 V 23/03, Guiding device for introduction of shank to side shaft, Inventors: Zaynullin A.G., Mukhametshin A.A., Ilalov R.Kh., Sabirov M.G., Romanov B.M., Garaev N.A.

6. Patent no. 2498043 RF, MPK E 21 V 29/00, Shoe valve for installation of shaped shutter in well, Inventors: Meling K.V., Bagnyuk S.G., Nasyrov A.L., Ismagilov M.A., Meling V.K.

7. Utility patent no. 56932 RF, MPK E 21 V 29/10, Soedinenie profil'nykh trub perekryvateley skvazhin (The connection of the profile pipe overlap wells), Inventors: Meling K.V., Akhmadishin F.F., Nasyrov A.L., Bagnyuk S.L., Khabibullin R.Ya.

8. Mukhametshin A.A., Nasyrov A.L., Mukhtarov I.F., Garaev N.A., The development of engineering and technology to restore the integrity of production casing strings and isolation of complications zones in sidetracks by profile packers (In Russ.), Inzhener-neftyanik, 2018, no. 4, pp. 34-40.

9. Iogansen K.V., Sputnik burovika (Driller satellite), Moscow: Nedra, 1986, pp. 153-158.

10. RD 39-00147001-767-2000. Instruktsiya po krepleniyu neftyanykh i gazovykh skvazhin (Instructions for oil and gas wells cementing), 2000, 214 p.

11. Patent no. 2117747 RF, MPK E 21 V 7/28, Bore-hole reamer, Inventors: Meling K.V., Abdrakhmanov G.S., Khamit'yanov N.Kh., Arzamastsev F.G., Mukhametshin A.A.

Full replacement of drilling mud by cement slurry can provide good-quality cementing and cement sheath integrity. Drilling of deviated and horizontal wells is often accompanied by presence of bottlenecks in the wellbore where drilling mud cannot be fully pumped down the annulus, which significantly reduces chances of good-quality cementing. The most efficient technique to solve this problem is casing movement (rotation, reciprocation) when cement slurry is placed into the borehole annulus. Casing string reciprocation has significant geological and technical constraints, while casing string rotation does not produce hydrodynamic load, providing additional cement flow turbulence and opening space to flush fluid and cement slurry. Numerous bench tests and model experiments proved that casing rotation significantly increases degree of drill mud replacement by cement slurry. However, casing rotation during well cementing jobs remains the least applied technique. This is primarily due to the lack of specialized wellhead equipment and threaded joints load limitation. The paper reviews development of casing-rotation-while-cementing technology in PJSC TATNEFT. The first casing rotation operations were performed in horizontal wells, where 245-mm casing strings with premium threads were cemented using mobile slant drilling rigs. Application of a rotating cementing head enabled continuous casing rotation with no need for shutoffs to squeeze the cement plug and significantly improved cementing quality. A unique equipment package for liner cementing in horizontal wells of Devonian formations has been developed and tested, which included a cementing rotary swivel and a disconnecting tool. A versatile rotating cementing head has been manufactured for cementing of 102-168-mm casing strings using drilling rigs equipped with a top drive or a rotor, which enabled wide application of casing rotation technique. Experience has shown that the key barrier for nonstop casing rotation during cementing jobs is torque limitation for buttress thread connections. Generally, the breakdown torque is reached when cement slurry goes behind the casing string and, at the same time, rotating resistance occurs due to concentric rotation of the casing string. Another limiting factor is the effect of torque and drag accompanied by the increased hook load, resulting in casing rotation stoppage. Nevertheless, acoustic and gamma-gamma cement-bond logs prove beneficial effect of casing rotation in obtaining a homogeneous cement sheath.

References

1. Yuhuan Bu et al., Effect of casing rotation on displacement efficiency of cement slurry in highly deviated wells, Journal of Natural Gas Science and Engineering, 2018, V. 52 (April), pp. 317–324. –

URL: https://www.sciencedirect.com/science/article/pii/S1875510018300544.

2. Quek Khang Song et al., Investigating the benefits of rotating liner cementing and impact factors, SPE 180578-MS, 2016, https://doi.org/10.2118/180578-MS.

3. Ryabokon' S.A., Mil'shteyn V.M., Lazarenko A.V., The device for boring casing rotation during its cementing (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2006, no. 5, pp. 72–73.

4. Akhmadishin F.F., Kirshin A.V., Iskhakov A.R. et al., Razrabotka ustroystva dlya vrashcheniya ekspluatatsionnoy kolonny pri ee tsementirovanii (Development of a device for rotating the production string during its cementing), Proceedings of Sbornik nauchnykh trudov TatNIPIneft' / PAO “Tatneft'”, 2016, V. 84, pp. 120–122.

5. Akhmadishin F.F., Kirshin A.V., Zaripov I.M., Iskhakov A.R., Kreplenie obsadnykh khvostovikov s vrash-cheniem v gorizontal'nykh stvolakh (Cementing casing shanks with rotation in horizontal trunks), Collected papers “Gorizontal'nye skvazhiny i GRP v povyshenii effektivnosti razrabotki neftyanykh mestorozhdeniy” (Horizontal wells and fracturing in increasing the efficiency of development of oil fields), Proceedings of International Scientific and Practical Conference devoted to the founder of horizontal drilling – Grigoryan A.M., Kazan', 6–7 September 2017, Kazan': Slovo Publ., 2017, pp. 117–120.

6. Shafigullin R.I., Akhmadishin F.F., Zaripov I.M. et al., Universal'naya tsementirovochnaya golovka (Universal cementing head), Proceedings of Sbornik nauchnykh trudov TatNIPIneft' / PAO “Tatneft'”, 2018, V. 86, pp. 233­–237.

7. Zaripov I.M., Iskhakov A.R., Zaripov A.M. et al., Razrabotka oborudovaniya s besprovodnymi registratorami momenta vrashcheniya i osevoy nagruzki dlya tsementirovaniya obsadnoy kolonny s odnovremennym ee vrashcheniem (Development of equipment with wireless recorders of torque and axial load for cementing the casing with its simultaneous rotation), Proceedings of Sbornik nauchnykh trudov TatNIPIneft' / PAO “Tatneft'”, 2018, V. 86, pp. 215–219.

In conditions of high depletion of a good part of Tatarstan oil fields well pattern arrangement has become a most important factor. The paper considers applicability of different well patterns to drain the residual reserves concentrated, mostly, in no-flow areas and by-passed oil zones of oil reservoirs. The objective of the study was to develop a concept and tools for computer-aided placement of project wells by dense irregular well spacing pattern that satisfies the production and economic constraints.A procedure for computer-aided stage-wise placement of project wells based on commercial production criteria was worked out. The procedure is realized in the program module for oil reserves evaluation in terms of production performance and economic efficiency of the hierarchical modeling package KIM-Expert – an in-house development of Tatneft PJSC. The optimization block generates a file of EOR/IOR jobs for recompletions and new completions with due account of the preset constraints on baseline economic efficiency of EOR/IOR jobs and allowable geological risks. The program module was used for analysis of 208 development targets of the Company. For each target, well pattern arrangement was selected, base reservoir performance indices were determined, as well as production and economic performance of multiple scenarios of well patterns. By the results of the calculations optimal scenarios were selected. Statistical analysis of distribution of initial parameters was performed in the best well pattern options. By example of development targets of one of the fields, the project wells were united in case they coincided in the general view. This approach allows either recompletion of wells or dual completion. The latter technology has a high potential for decreasing of capital and operating expenses, and facilitates early production of multilayered fields. The carried out analysis allowed ranking of similar development targets in terms of future economic performance. The obtained results were submitted for approval and validation by specialists of the Company’s Oil and Gas Production Units and Reservoir Engineering Department.

References

1. Certificate of authorship no. 2018613935 RF, Tekhniko-ekonomicheskaya otsenka zapasov neftyanogo mestorozhdeniya (Technical and economic assessment of oil field reserves), Authors: Latifullin F.M., Sattarov Ram.Z., Smirnov S.V., Khanipov M.N., Khafizov R.R., Sharifullina M.A.

2. Certificate of authorship no. 2018611091 RF, KIM Ekspert (Complex for hierarchical modeling “Ekspert”), Authors: Sakhabutdinov R.Z., Ganiev B.G., Nasybullin A.V., Latifullin F.M., Sattarov Ram.Z., Smirnov S.V., Sharifullina M.A.

3. Latifullin F.M., Sattarov Ram.Z., Smirnov S.V. et al., Sozdanie programmnogo modulya dlya tekhniko-ekonomicheskoy otsenki zapasov nefti PAO “Tatneft'” (Creating a software module for the technical and economic assessment of oil reserves of PJSC TATNEFT), Proceedings of TatNIPIneft', 2018, V. 86, pp. 49–57.

4. Nasybullin A.V., Razzhivin D.A., Latifullin F.M. et al., Optimization of project wells’ placement using software module for oil production and economic analysis (In Russ.), Neftyanaya provintsiya, 2018, no. 4, pp. 163–174, URL: http://docs.wixstatic.com/ugd/2e67f9_4cc6391aa88d4ba18effd2bcc96e0481.pdf.

5. Ccertificate of authorship no. 2009616218 RF, Avtomatizirovannoe rabochee mesto geologa “LAZURIT” (Automated workplace of geologist “LAZURIT”), Authors: Akhmetzyanov R.R., Ibatullin R.R., Latifullin F.M., Nasybullin A.V., Smirnov S.V.

6. Nasybullin A.V., Latifullin F.M., Razzhivin D.A. et al., Creation and commercial introduction of methods of oil deposits development management on the basis of computer-aided design technologies (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2007, no. 7, pp. 88–91.

7. Latifullin F.M., Sattarov Ram.Z., Sharifullina M.A., Application of lazurit workstation software package for geological and reservoir modeling and well intervention planning for Tatneft’s production assets (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 6, pp. 40–43.

8. Sharifullina M.A., Butusov E.V., Development of hierarchical modelling software for reservoir simulation, field management and selection of appropriate well stimulation technologies (In Russ.), Neftyanaya provintsiya, 2017, no. 4, pp. 116–124, URL: http://docs.wixstatic.com/ugd/2e67f9_9c3ae734e23f48­b3a6f0ec08ae79e9eb.pdf.

Many of the currently producing extra-heavy oil fields have entered the closing stage of development, so the correct ceasing of production is a matter of acute importance. This is particularly true for shallow heavy oil reservoirs developed by steam-assisted gravity drainage (SAGD) method involving continuous injection of large volumes of steam into a subsurface formation. The problem is that once the steam injection stops, the injected steam cools and condenses decreasing dramatically in volume and bringing about a sharp decrease of formation pressure. Considering that most of heavy oil reservoirs occur at shallow depths this may be detrimental to environment and can even alter the soil surface.

Various options to cease heavy oil production by example of a heavy oil reservoir in the Sheshminskian formation in Tatarstan developed by the SAGD method were analyzed. The laboratory experiment was modeled on a digital core, and a digital core twin was created to be used in the live reservoir model. Different production ceasing options were considered. A base case provided for steam injection till complete depletion of the reservoir, i.e. development going on in the normal course. Also, options providing for stop of steam injection in different years since start of development were considered and key performance parameters (steam-oil ratio (SOR), cumulative oil production, steam injection) were analyzed.

The paper presents recommendations on criteria for application of production ceasing strategies (stop of steam injection) to cut down steam generation costs, decrease SOR, and minimize oil losses.

References

1. Zaripov A.T., Beregovoy A.N., Shaykhutdinov D.K., Khafizov R.I., Zakharov Ya.V., Bisenova A.A., Improving the efficiency of steam-assisted heavy oil production using gel-forming systems (In Russ.), Tekhnologii nefti i gaza, 2018, no. 1, pp. 35–38.

2. Bisenova A.A., Shaykhutdinov D.K., Otsenka effektivnosti kompleksnoy tekhnologii primeneniya parogravitatsionnogo drenirovaniya i zakachki goryachey vody na zalezhakh sverkhvyazkoy nefti (Assessment of the effectiveness of the integrated technology for the use of steam and gravity drainage and hot water injection in super-viscous oil deposits), Proceedings of Youth Scientific and Practical Conference of TatNIPIneft, Bugul'ma: Publ. of TatNIPIneft', 2018, URL: http://tatnipi.ru/upload/sms/2018/geol/005.pdf.

3. Zaripov A.T., Shaykhutdinov D.K., Analiz posledstviy i riskov ostanovki zakachki para na pozdney stadii razrabotki zalezhey sverkhvyazkoy nefti (Analysis of the consequences and risks of stopping steam injection at a late stage of development of extra-viscous oil deposits), Proceedings of TatNIPIneft' / PAO “Tatneft'”, 2018, V. 86, pp. 85–89.

4. Zaripov A.T., Shaykhutdinov D.K., Analysis of SAGD-wells shutdown effects (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 7, pp. 36–39.

5. Patent no. 2611789. MPK E 21 B 43/24, S 09 K 8/592, Method of development of field of high viscous and ultra high viscous oil by thermal methods at late stage of development, Inventors: Zaripov A.T., Amerkhanov M.I., Shesternin V.V.

Inflow performance relationship (IPR) shows a peak flow rate corresponding to the limited bottomhole pressure at significant flowing bottomhole pressure drop in producing wells. It follows that oil production can be improved if a well can be made to produce at a limited bottomhole pressure. So, the objective of the research was to upd ate data on limited bottomhole pressures in the main assets of Tatneft PJSC. The tests were carried out in 79 wells, including, 40 wells completed in the Devonian sandstone reservoirs, 19 wells in the Carboniferous sandstone reservoirs, and 20 wells in carbonate reservoirs. To ensure data reliability, pressure downhole gauges se t at formation tops were used in 64 wells. For the first time ever, measurements of limited bottomhole pressure were performed in eight horizontal wells. The research included determination of relationships between oil and fluid production rates and flowing bottomhole pressures (IPR curves) for all wells; we also considered deterioration of reservoir properties at pressure decrease and their improvement at pressure increase. The results of laborious and extensive tests suggest the following tendencies. Limited bottomhole pressures corresponding to peak production have been obtained in 83 % of wells; the remaining IPR curves have no production extremum. Generally, limited pressures and limited pressure-bubble point pressure relationships vary significantly, even within the same reservoir rock. This can, presumably, be accounted for varying physicochemical properties of oil, permeability to gas and oil, flow capacity, etc. No relationship between limited pressure and water cut within the same reservoir rock has been found; neither was determined any significant difference between limited pressures for fluid and oil production. The latter can be explained by relatively stable water cut profile. Decrease of the bottomhole pressure to the value of the limited pressure and even lower brings about decrease of well deliverability. The IPR curves with the recorded FBHP decrease and increase testify to incomplete permeability and porosity restoration once bottomhole pressure has increased following the period of well operation at low FBHP. It should be noted, however, that these variations are at the level of flowrate measurement error. It was found that the limited bottomhole pressures in horizontal wellbores are higher than in vertical wellbores. A possible explanation is that a larger area around the wellbore has been damaged because of gas coming out of solution in this area. On the whole, the carried out tests yielded valuable information, which will help the Company to improve the efficiency of oil production operations. The possible economic effect is estimated at a level of billion Russian rubles.

References

1. Muslimov R.Kh., Zaynullin N.G., Diyashev R.N., Zinnatov I.Kh., Justification of optimal bottomhole pressure for terrigenous reservoirs (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 1984, no. 9, pp. 27–29.

2. Diyashev R.N., Sovmestnaya razrabotka neftyanykh plastov (Joint development of oil reservoirs), Moscow: Nedra Publ., 1984, 207 p.

3. Mishchenko I.T., Skvazhinnaya dobycha nefti (Oil production), Moscow: Neft’ i gaz Publ., 2015, 448 p.

4. Vogel J.V., Inflow performance relationships for solution gas drive wells, Journal of Petroleum Technology, 1968, V. 20, no. 1, pp. 83–92, DOI: 10.2118/1476-PA.

5. Fetkovich M.J., The isochronal testing of oil wells, SPE 4529-MS, 1973, DOI: 10.2118/4529-MS.

6. Wiggins M.L., Generalized inflow performance relationships for three-phase flow, SPE 25458-MS, 1993, DOI: 10.2118/25458-MS.

7. Iktissanov V.A., Bobb I.F., Ganiev B.G., Study of the problem of optimization of bottomhole pressure for fractured-porous reservoirs (In Russ.), Neftyanoe khozyaystvo = Oil Industry, Neftyanoe khozyaystvo, 2017, no. 10, pp. 94–97.

8. Iktissanov V.A., Patterns control the development of oil fields using optimization bottom-hole pressures for the porous collector (In Russ.), Burenie i neft', 2017, no. 3, pp. 14–18.

The main oil reserves of Tatneft PJSC have entered the mature stage with more than 80% of oil in place original oil-in-place having been recovered. More than half of oil comes from the depleted sandstone reservoirs with recoverable reserves steadily declining. The share of hard-to-recover reserves in the Company’s assets’ structure is more than 78%. However, production enhancement operations carried out by the Company on a wide scale help to maintain a stable level of oil production. Enhanced oil recovery (EOR) technologies are not able to provide for the maximum oil recovery unless concrete geological environment and reservoir properties are given intense attention. The Company has been successfully developing and introducing own EOR technologies that meet the challenging in-situ conditions. Novel oil recovery processes extend reservoir life, which is particularly important under the volatile market conditions. The depleted reservoirs developed by waterflooding still have a considerable potential, and chemical flooding is one of the most effective ways to displace the residual reserves. A great number of different chemical EOR methods have been tested and applied in the Company’s fields, however, just few technologies have proved the most effective. One of the technologies that really work is injection of hydrophobic emulsion systems. The works started at TatNIPIneft more than ten years ago. Since then, a large number of different compositions and injection methods have been tested in laboratory and in field.

Currently, emulsion-based technologies loom large in chemical EOR portfolio of the Company. The full technology cycle has been developed, from the QA production of emulsifying agent, preparation of compositions for injection, and application of the technology in a wide range of geological and reservoir conditions.

References

1. Patent no. 2153576 RF, MPK E 21 V 43/22, Reverse emulsion for treating oil strata, Inventors: Seleznev A.G., Kryanev D.Yu., Makarshin S.V.

2. Patent no. 2110675 RF, MPK E 21 V 43/22, Invert microemulsion for treating oil beds.

3. Patent no. 2379326 RF, MPK C 09 K 8/584, Water repellent emulsion for oil reservoirs treatment, Inventors: Ibatullin R.R., Amerkhanov M.I., Rakhi­mova Sh.G., Beregovoy A.N., Andriyanova O.M., Khisamov R.S.

4. Beregovoy A.N., Amerkhanov M.I., Rakhimova Sh.G., Vasil'ev E.P., Application of invert emulsions enhances conformance in heterogeneous formations (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2010, no. 8, pp. 116–118.

5. Patent no. 2613975 RF, MPK V 01 F 17/00, C 09 K 8/00, C 11 D 1/04, 3/43. Invert emulsions emulsifier, Inventors: Sakhabutdinov R.Z., Beregovoy A.N., Rakhimova Sh.G., Andriyanova O.M., Fadeev V.G., Amerkhanov M.I., Nafikov A.A.

6. Patent no. 2660967 RF, MPK E 21 V 43/22, C 09 K 8/92, E 21 V 43/16, Method of treating non-uniform permeability oil reservoir by injection of invert emulsion, Inventors: Zaripov A.T., Beregovoy A.N., Rakhimova Sh.G., Medvedeva N.A., Lakomkin V.N., Amerkhanov M.I., Nafikov A.A.

Once the steam-assisted gravity drainage (SAGD) method has begun to be used on a wide scale to produce heavy oil/bitumen reserves it has become possible to develop reservoirs with immobile hydrocarbons. The economics of the SAGD process strongly depends on the steam generation efficiency, steam delivery, and steam usage efficiency in successful and unsuccessful SAGD well pairs. The success of a SAGD well pair is often dictated by how efficiently steam is used in the inflow/injection profile of a SAGD well pair. Completions involving inflow control devices (ICDs) promise to improve the economics of the process by improving the inflow profile and mitigating the irregularities in steam injection and fluid production along the horizontal wellbore. Traditionally, ICDs have been used in lengthy wellbores characterized by pressure drops along the entire length to control and equalize the inflow profile and to delay water breakthrough. In SAGD wells, ICDs have found new application providing for a uniform steam distribution in the injection well and an evenly distributed fluid flow profile in the producing well, maximizing, thus, the heavy oil recovery. The operation of autonomous inflow control devices is based on increase of resistance to flow in response to increase of fluid rate through a section in heavy oil completions. The paper presents the results of research into the effectiveness of ICDs, principle of their operation, and applicability in Tatarstan heavy oil fields. Algorithm of ICD losses calculation was determined, and ICD losses for wells producing heavy oil were calculated. Typical cases were considered, variations in productivity of horizontal wellbore sections with ICDs were determined by calculation. The results of the research show that ICD can partially choke the problem intervals (by 10 % zones with water coning and by 2 % zones with steam breakthrough), and help to achieve an evenly distributed flow profile along a horizontal well. Thermodynamic analysis of two types of inflow control devices was performed, ICD losses calculating formulae were adapted to be used in reservoir flow models, and ICD long-term effect considering changes in reservoir conditions was assessed.

References

1. Zaripov A.T., Shaykhutdinov D.K., Bisenova A.A., Khafizov R.I., Improving the efficiency of development of horizontal wells using steam and gravity drainage technology for highly viscous oil (In Russ.), Tekhnologii nefti i gaza, 2018, no. 6, pp. 26–30.

2. Zaripov A.T., Shaykhutdinov D.K., Khafizov R.I. et al., Analiz tekushchego sostoyaniya i sovershenstvovanie usloviy raboty skvazhin zalezhey sverkhvyazkoy nefti s ispol'zovaniem teplovogo gidrodinamicheskogo modelirovaniya (Analysis of the current state and improvement of the operating conditions of wells with extra-viscous oil deposits using thermal hydrodynamic modeling), Proceedings of TatNIPIneft', 2017, V. 85, pp. 173–181.

3. Zaripov A.T., Beregovoy A.N., Shaykhutdinov D.K., Khafizov R.I., Zakharov Ya.V., Bisenova A.A., Improving the efficiency of steam-assisted heavy oil production using gel-forming systems (In Russ.), Tekhnologii nefti i gaza, 2018, no. 1, pp. 35–38.

4. Khafizov R.I., Zaripov A.T., Shaykhutdinov D.K., Otsenka effektivnosti primeneniya geleobrazuyushchikh kompozitsiy na zalezhakh SVN s ispol'zovaniem termogidrodinamicheskogo modelirovaniya (Evaluation of the effectiveness of the use of gel-forming compositions on deposits with extra-viscous oil using thermo-hydrodynamic modeling), Proceedings of International Scientific and Practical Conference “Modelirovanie geologicheskogo stroeniya i protsessov razrabotki – osnova uspeshnogo osvoeniya neftegazovykh mestorozhdeniy” (Simulation of the geological structure and development processes - the basis for the successful development of oil and gas fields), 4–5 September 2018, Kazan': Slovo Publ., 2018, pp. 384.

Operation of directional and horizontal wells at maximum production rates requires placement of a downhole pump inside the horizontal well section. Several special-purpose downhole sucker-rod pump designs intended for operation of directional and horizontal wells have been considered. These are ELKAM’s differential piston pump with plunger mechanical seal provided by Ecogermet-M; downhole pump of Bavlyneft Oil and Gas Production Department of Tatneft PJSC, equipped with a suction valve with self-adjusting gate and conventional ball-type delivery valve; Packer Research and Production Company’s pump provided with suction and delivery valves with self-adjusting gates and, finally, downhole pump designed at TatNIPIneft Institute, consisting of a plunger with controllable delivery valve and a spring-operated ball-type suction valve. Additional tensile load on pump rods in differential pumps is a product of cross sectional area of hydraulic power booster pushrod and pressure determined by the distance from wellhead to dynamic fluid level. Valves are forced open and closed by friction forces: in the suction valve, it is the friction of valve seal on hydraulic power booster pushrod, in travelling valve – friction of plunger seals on pump barrel. Flow rate of such pump is proportional to the difference between cross sectional areas of pump plunger and hydraulic power booster pushrod and is less than the flow rate of conventional pump with similar plunger diameter. Practical applications have demonstrated that with low viscosity of the produced fluid the weight of rod string in nominally vertical well section is typically sufficient to ensure steady downward rod movement in horizontal and directional wells. Results of field tests in wells of Tatneft PJSC are provided. Advantages and disadvantages of special-purpose pump designs for directional and horizontal wells are discussed, as well as lessons learned from real field trials. Recommendations for implementation of different downhole sucker-rod pumps for operation of directional and horizontal wells as well as for oil production from lateral holes are given.

References

1. Urazakov K.R., Ekspluatatsiya naklonno napravlennykh skvazhin (Operation of directional wells), Moscow: Nedra Publ., 1993, 168 p.

2. Zakharov B.S., Spetsial'nye tipy shtangovykh nasosov (Special types of sucker rod pumps), Moscow: Publ. of VNIIOENG, 2010, 136 p.

3. Zakharov B.S., Zakharov I.B., Differential sucker-rod pump for directional and horizontal wells (In Russ.), Oborudovanie i tekhnologii dlya neftegazovogo kompleks, 2014, no. 3, pp. 8–11.

4. Patent no. 2382904 RF, MPK, F 04 V 53/00, F 16 K 15/04, Downhole pump adjustable valve, Inventors: Ibragimov N.G., Akhmetshagiev F.K., Gil'fanov Rustam A., Gil'fanov Ruslan A.

5. Patent no. 2623345 RF, MPK F 04 V 47/00, Rod well pump for horizontal wells, Inventors: Nagumanov M.M., Kamil'yanov T.S., Akhmetshagiev F.K.

Efforts were made to develop effective technologies to break stable water-in-oil emulsions stabilized by solid particles. The paper presents the results of the research studies. Based on the laboratory research, a number of technologies have been developed for breaking of stable water-in-oil emulsions and obtaining of on-spec oil with water cut up to 1 %, iron sulfide content up to 200 mg/dm3, and solids content up to 0.1 %wt. The technology of thermochemical treatment involves circulation of stable water-in-oil emulsion in the process loop, heating, diluting, and adding chemical agents. The technology of acid treatment involves circulation of stable water-in-oil emulsion in the process loop, heating, and adding acid. The technology of stage combined treatment combines the technology of thermochemical treatment at stage one, using diluents and chemical agents, and the technology of acid treatment at stage two, using acid.

The technologies of acid treatment and stage combined treatment were tested at the Tatneft PJSC battery. The test was very successful: more than 90% of oil contained in the feed water-in-oil emulsion was recovered. The economics of the process was also attractive. Commercialization of these technologies will allow the Company to cut down expenses related to emulsion disposal services of outside companies; also the volume of additional on-spec oil will be increased.

References

1. Sakhabutdinov R.Z., Gubaydulin F.R., Ismagilov I.Kh., Kosmacheva T.F., Osobennosti formirovaniya i razrusheniya vodoneftyanykh emul'siy na pozdney stadii razrabotki neftyanykh mestorozhdeniy (Features of formation and destruction of oil-water emulsions at a late stage of oil field development), Moscow: Publ. of OAO “VNIIOENG”, 2005, pp. 229–236.

2. Sakhabutdinov R.Z., Gubaydulin F.R., Kosmacheva T.F., Tat'yanina O.S., The causes of water-oil emulsion stability increase (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2007, no. 1, pp. 74–77.

3. Sakhabutdinov R.Z., Kosmacheva T.F., Gubaydulin F.R., Makhmutova G.R., Peculiarities of intermediate layers formation while oil dehydration (In Russ.), Neftepromyslovoe delo, 2009, no. 10, pp. 42–46.

4 Shavaleev. I.I., Sakhabutdinov R.Z., Tronov V.P. et al., Tekhnologiya obrabotki promezhutochnykh sloev iz apparatov podgotovki nefti (Processing technology of the intermediate layers of oil treatment apparatus), Proceedings of scientific and technical conference “Bol'shaya neft': realii, problemy, perspektivy” (Big oil: realities, problems, prospects), Al'met'evsk, 2001, pp. 182–189.

5. Akhmetshina E.I., Gubaydulin F.R., Sudykin S.N., Karavashkina L.S., Razrabotka tekhnologiy razdeleniya promezhutochnykh sloev, obrazuyushchikhsya na ob"ektakh podgotovki nefti PAO “Tatneft'” (Development of technologies for the separation of intermediate layers formed at the oil treatment facilities of Tatneft PJSC), Proceedings of TatNIPIneft' / PAO “Tatneft'”, 2018, V. 86, pp. 258–265.

6. STO TN 234-2017, Instruktsiya po primeneniyu tekhnologiy obrabotki promezhutochnykh sloev (Instructions for the use of technologies for processing intermediate layers), Bugul'ma: Publ. of TatNIPIneft' PAO “Tatneft'”, 2017, 48 p.

7. Patent no. 2671565 RF, MPK C 10 G 33/04, 33/06, Method for processing intermediate layer stabilized by iron sulphide, using inhibited salt acid (options), Inventors: Akhmetshina E.I., Gubaydulin F.R., Sudykin S.N.

8. Patent no. 2678589 RF, MPK C 10 G 33/04, Method of complex processing of an intermediate layer stabilized by iron sulfide, Inventors: Akhmetshina E.I., Gubaydulin F.R., Sudykin S.N., Karavashkina L.S., Urazov I.I., Mirgaliev I.R.

The paper presents justification for normative standards concerning permissible residual oil content and products of its transformation in industrial soils after recultivation and soil remediation operations. The test objects were samples of soils with background matter content and recultivated soils of nine types collected on the territories of Tatneft PJSC E&P activities, as well as model samples contaminated with the most toxic sulfur crude oil produced from the Carboniferous reservoirs. The model samples met the requirements concerning the content of dissolved solids of aqueous extracts of soils, chlorides, sulfates, and heavy metals. The experimental justification of normative standards was based on four basic nuisance values: migratory aqueous, migratory air, translocation, and general sanitary nuisance values, in compliance with the principles of regulation of industrial lands’ soils. General sanitary tests using oil-contaminated model soil samples included determination of population of main groups of soil micro-organisms: heterotrophs, hydrocarbon-oxidizing, spore-forming actinomycetes, micromycetes, nitrogen fixers, I phase nitrifiers; fermentation activity of soil microflora (urease and catalase); parameters of soil respiration (basal respiration, substrate-induced respiration, content of carbon in bacterial biomass, coefficient of bacterial respiration); biotesting of aqueous extracts of model soils using monocotyledon seeds (spring wheat, Triticum vulgare L.); biotesting of aqueous extracts of model soils to determine presence of Ceriodaphnia affinis and Paramecium caudatum; determination of acute toxicity using monocotyledon seeds (Triticum vulgare L.) and chronic phytotoxicity using higher monocotyledon (Triticum vulgare L.) and dicotyledon (field pea, Pisum sativum L.) plants. As a target normative standard, the least content of oil products was selected out of the experimental data on the four nuisance values. When establishing normative standards concerning permissible residual concentration of oil products in soils, it was found that the migratory aqueous and the migratory air nuisance values are not limiting in the tested range of concentrations, while the general sanitary nuisance value is limiting. Based on the results of the surveys considering the limiting content of oil products in the model soil samples and taking into account the assumed error (25 %) for the methods to determine the mass fraction of oil products in soil for the purpose of the state ecological monitoring, we recommend the following normative standards concerning permissible concentration of oil products for Tatarstan soils: 10 g/kg for soddy-calcimorphic leached, light-gray forest soil; 11 g/kg for soddy-calcimorphic podzolized, sod-podzol, gray forest soil, dark-gray forest soil; 12 g/kg for typical black humus earth (chernozem), leached and podzolized.

References

1. Ibragimov N.G., Gareev R.M., Ismagilov I.F., Kubarev P.N., Shaydullina I.A., Regulatory support for reclamation of disturbed and oil-contaminated soils in Tatneft PJSC assets (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 5, pp. 74–77.

2. Malykhina L.V., Shaydullina I.A., Kolesnikova N.E., Antonov N.A., Working out of measures on recultivation of soils disturbed under the construction and operation of oil-field facilities (In Russ.), Zashchita okruzhayushchey sredy v neftegazovom komplekse, 2012, no. 10, pp. 10–13.

3. Shaydullina I.A., Yapparov A.Kh., Degtyareva I.D., Latypova V.Z., Gadieva E.Sh., Recultivation of oil-contaminated lands by example of leached black humus earth of Tatarstan (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2015, no. 3, pp. 102–105.

4. Ibatullin R.R., Mutin I.I., Iskhakova N.M., Shaydullina I.A., Sakhabutdinov K.G., Pavlyuk N.V., Development of a standard for the permissible residual oil content for leached chernozems of the Republic of Tatarstan (In Russ.), Interval, 2006, no. 2, pp. 10–16.

5. Shaydullina I.A., Tipovoy proekt rekul'tivatsii narushennykh zemel' (kategorii “zemli promyshlennosti”) (Typical reclamation of disturbed land (category "industrial land")), Bugul'ma: Publ. of TatNIPIneft', 2013, 26 p.

6. Shaydullina I.A., Normirovanie i minimizatsiya obrazovaniya i opasnosti neftezagryaznennykh pochv dlya prirodnoy sredy (na primere OAO “Tatneft'”) (Normalization and minimization of the formation and danger of oil contaminated soils for the natural environment (by the example of Tatneft)): thesis of candidate of chemical science, Kazan', 2006.

7. Shoba S.A., Trofimov S.Ya., Avetov N.A. et al., Ekologicheskoe normirovanie soderzhaniya nefti v pochvakh taezhnoy zony Zapadnoy Sibiri (Ecological rationing of the oil content in the soils of the taiga zone of Western Siberia), Collected papers “Novye tekhnologii dlya ochistki neftezagryaznennykh vod, pochv, pererabotki i utilizatsii nefteshlamov” (New technologies for the purification of oil-polluted water, soil, processing and disposal of oil sludge) Proceedings of International Conference, Moscow, 10–11 December 2001, Moscow: Noosfera Publ., 2001, pp. 125–127.

8. Yakovlev A.S., Nikulina Yu.G., Evdokimova M.V., Printsipy ekologicheskogo normirovaniya pochv zemel' raznogo khozyaystvennogo naznacheniya (Principles of ecological rationing of soils in lands of various economic purposes), Collected papers “Fundamental'nye dostizheniya v pochvovedenii, ekologii, sel'skom khozyaystve na puti k innovatsiyam” (Fundamental achievements in soil science, ecology, agriculture on the way to innovations), Proceedings of I All-Russian Scientific and Practical Conference, 23–25 April 2008, Moscow: MAKS Press Publ., 2008, pp. 291–292.

9. Ekologicheskoe normirovanie i upravlenie kachestvom pochv i zemel' (Ecological rationing and soil and land quality management): edited by Shoba S.A., Yakovlev A.S., Rybal'skiy N.G., Moscow: NIA-Priroda Publ., 2013, 309 p.

10. Kovaleva E.I., Yakovlev A.S., Scientific approaches to rationing of petroleum contaminations of soils (In Russ.), Ekologiya i promyshlennost' Rossii, 2016, V. 20, no. 10, pp. 50–57.

11. Shagidullin R.R., Latypova V.Z., Ivanov D.V. et al., The rationing of allowable residue of petroleum and its transformation products in soils (In Russ.), Georesursy = Georesources, 2011, no. 5 (41), pp. 2–5.

12. Blagodatskaya E.V., Anan'eva N.D., Myakshina T.N., Characteristics of soil microbial community by the metabolic coefficient Ye (In Russ.), Pochvovedenie, 1995, no. 2, pp. 205–210.

13. Petrov A.M., Zaynulgabidinov E.R., Shagidullin R.R. et al., Development of standards for permissible residual content of oil and its transformation products in soils for the forest fund lands of the Republic of Tatarstan (In Russ.), Vestnik Kazanskogo tekhnologicheskogo universiteta, 2013, V. 16, no. 20, pp. 265–270.

Industrial environmental control over development of oil fields is the main tool of geoecological monitoring. Because of the man-induced impact associated with upstream activities, monitoring of the state of surface hydrosphere is of most interest. In the framework of ecological-hydrogeological surveys on the territories of Tatneft PJSC upstream activities on the south-western slope of the South-Tatarian Arch, hydrological monitoring of the fluvial network in the south-eastern part of Tatarstan has been carried out. Because of the advancement of the monitoring system, the list of determined micro components in water was expanded. Determination of the content of manganese, iron, copper, zinc, and nickel provided information about concentration of heavy metals, which top the list of toxicological hazards. Besides, assessment of the current environmental state requires that background concentrations of heavy metals on the exploratory prospects shall be registered. Analysis of heavy metals content in surface waters on the territory of the company’s operations as of 2018 was performed. Quality of water in the Stepnoi Zai, the Sheshma and their stream tributaries was assessed in quantitative terms using the water pollution index (WPI). Water in the Stepnoi Zai was classed as polluted (class of quality IV), water in the Sheshma was classed as moderately polluted (class of quality III). In the stream tributaries WPI is higher as a rule. The survey results indicate marked override of heavy metal concentrations in the Stepnoi Zai, the Sheshma and their stream tributaries. Component analysis along the thalweg of the river stretches under survey was performed. Content of all metals increases in the Sheshma left-bank tributaries from the river mouth to the river source. Principles of forming of heavy metals and mechanisms of their entry into rivers were studied. Mainly, heavy metals naturally migrate from soils in the south-east of Tatarstan characterized by high background concentrations of manganese, chrome, copper, zinc, nickel, and cobalt. The man-made heavy metal source was studied by the example of the Stepnoi Zai. It was found that concentrations of some metals increase after waste water disposal because of poor performance of effluent treatment facilities.

References

1. Kubarev P.N., Aslyamov N.A., Petrova G.I. et al., Study of hydrogeological environment in heavy oil reservoirs developed by thermal method (In Russ.), Neftyanoe khozyaystvo=Oil Industry, 2018, no. 7, pp. 49–52.

2. Protasova N.A., Shcherbakov A.P., Mikroelementy (Cr, V, Ni, Mn, Zn, Cu, Co, Ti, Zr, Ga, Be, Ba, Sr, B, I, Mo) v chernozemakh i serykh lesnykh pochvakh Tsentral'nogo Chernozem'ya (Trace elements (Cr, V, Ni, Mn, Zn, Cu, Co, Ti, Zr, Ga, Be, Ba, Sr, B, I, Mo) in black soil and gray forest soils of the Central Black Soil Region), Voronezh: Publ. of VSU, 2003, 368 p.

3. Kasimov N.S., Ekogeokhimiya landshaftov (Ecogeochemistry of landscapes), Moscow: IP Filimonov M.V. Publ., 2013, 208 p

4. Shitikov V.K., Rozenberg G.S., Zinchenko T.D., Kolichestvennaya gidro­ekolo­giya: metody sistemnoy identifikatsii (Quantitative hydroecology: methods of system identification), Tol'yatti: Publ. of IEVB RAS, 2003, 463 p.

5. Malye reki Volzhskogo basseyna (Small rivers of the Volga basin): edited by Alekseevskiy N.I., Moscow: Publ. of MSU, 1998, 234 p.

6. Ivanov D.V., Heavy metals in soils of the Republic of Tatarstan (an overview) (In Russ.), Rossiyskiy zhurnal prikladnoy ekologii, 2015, no. 4, pp. 53–60.

Environmental impact of oil production activities is observed at each stage of field development. Being a complex and responsible type of activity, oil prospecting and production has an environmental impact, including adverse effects on atmospheric air, surface and ground water, soil, biota and, ultimately, on human health. At the same time, objective environmental conditions in oil production regions depend on production activity of other enterprises associated with various sectors of the national economy. Environmental response to anthropogenic and industrial stresses becomes apparent at local and regional scales. At its production sites, Tatneft undertakes comprehensive dedicated efforts aimed at increasing the environmental safety of oil production processes. It is essential that environmental footprint of oil field development and other production and economic activities be reduced through creation, improvement and implementation of innovative methods and technologies, establishment of environmental monitoring system.

The main criteria of efficiency of environmental conservation efforts is the condition of atmospheric air, surface and ground water, soil and subsurface. This data is provided by industrial environmental monitoring conducted at four levels. The first is outer-space level – interpretation of photos of various physical natures depending on applied task to be solved at regional scale. At the aerospace level interpretation of photos of various physical natures depending on applied task to be solved at local scale is carried out. The surface level considers in-field ecological and groundwater studies, geological and geomorphological studies, geophysical and landscape surveys; corrosion prevention diagnostics of oil production facilities. The last one is downhole level – in-field areal and downhole geophysical surveys, drilling of appraisal and groundwater observation wells.

The present research work aims at comparative analysis of environmental baseline and current environmental conditions of natural environment components on the territory of Kurmanaevskoe oil field operated by Tatneft. The authors evaluate the present field development status and the nature of human-induced environmental stresses. Physical environment, geographical setting and groundwater conditions are described, as well as utility and drinking water supply system of residential areas within the territory of the field. The paper also reveals the main activities focused on reducing the ecological footprint of oil field production operations. Underway is industrial environmental monitoring for evaluation of current ecological state of field territory. The authors analyze the results of laboratory studies of natural environment components conducted prior to commercial development of the field and during the last decade. This analysis facilitates assessment of efficiency of environmental control measures.

The article is devoted to the development of seismic-geological criteria for predicting oil deposits associated with fractured formations of the pre-Jurassic complex of the north-eastern part of the Krasnoleninsky arch of Western Siberia, represented by Paleozoic formations and the weathering crust. On the basis of complex interpretation of seismic materials, geophysical well surveys and analytical studies using seismic facies, dynamic wave field, seismic and geological criteria for identifying zones of fractured reservoirs and searching for oil and gas prospective objects were considered. A comprehensive approach to the interpretation of seismic materials, deep drilling data, well logging and core analysis materials allows to solve subtle problems of forecasting the geological section and map complex oil and gas prospective objects. The identified oil deposits in the pre-Jurassic complex are confined to local protrusions of the basement with deep faults that control localized flows of hydrocarbon fluids. The decisive factor determining the localization of hydrocarbons in low-permeable strata is the secondary formation of their reservoirs of fracture, cavern, and mixed types. In addition to forecasting the planned position of local elevation dimensions, with which most of the identified promising areas are associated, the possibility of using 3D seismic survey materials for forecasting productive intervals in a geological section is shown. The analysis of testing and the dynamics of the drilled well stock in the studied area confirms the identified pattern of matching productive intervals of wells of the Paleozoic object with traceable anomalies in the vertical sections of the cube of seismic attributes based on 3D seismic materials.

As part of the monitoring of the geo-model of the Paleozoic object, differentiation of the brightest anomalies of the fall of amplitudes in the upper part of the Paleozoic formations was carried out within extensive disintegration zones, which made it possible to draw up a detailed pattern with a local pattern of propagation of areas of increased fracturing according to which it was proposed to take into account structural prediction of promising areas factor and results of well testing.

References

1. Bekkina S.M., Kurilenkova G.A., Sidnev A.V., Basic geological criteria of an oil-and-gas content for pre-Jurassic basement of Frolovskaya megabasin of the Shirotnoye Priobye (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2009, no. 10, pp. 38–40.

2. Tugareva A.V., Chernova G.A., Yakovleva N.P., Moroz M.L., Geological structure and oil and gas potential of the Pre-Jurassic deposits of the central part of the West Siberian plate (In Russ.), Izvestiya vuzov. Neft' i gaz, 2017, no. 5, pp. 58–66.

3. Shadrina S.V., Kondakov A.P., New data on the basement of the north-eastern framing of Krasnoleninskiy arch (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2014, no. 11, pp. 94–99.

4. Bembel' R.M., Vysokorazreshayushchaya ob"emnaya seysmorazvedka (High resolution three-dimensional seismic), Novosibirsk: Nauka Publ., 1990, 152 p.

5. Bembel' S.R., Efimov V.A., Petrophysical interpretation of well geophysical studies and a geological model of an object formed by metamorphic rocks (In Russ.), Collected papers “Petrofizika slozhnykh kollektorov: problemy i perspektivy 2015” (Petrophysics of complex reservoirs: Problems and Prospects 2015): edited by Enikeev B.N., Moscow: EAGE Geomodel', 2015, pp. 96–116.

6. Kondakov A.P., Bembel' S.R., Tseplyaeva A.I., A refinement of the PZ-object geological model based on the geological and geophysical data analysis (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 4, pp. 26–30.

Hydrocarbon resource assessment and estimation oil and gas reserves source-rock reservoirs within the Bazhenov formation of Western Siberia require a comprehensive study of their water content. So far, the petroleum industry has been using known laboratory methods for direct determination of water content for low-permeable shale Bazhenov formation rocks. However, the question of data validity and quality remains open since the legacy methods have been developed for conventional reservoirs. The article presents a new laboratory method for measuring the water content, explicitly designed for shale rocks with initially low water content (less than 5% wt.). The proposed evaporation method allows determining the amount of free and physically bound water in rock samples with a mass of 25-70 g within 1-3 h. The error in determining the mass water content for in evaporation method depends on the initial water content and is 0.2-6.8% wt.

Testing of the evaporation method included a target collection of whole core samples with the maximum preserved natural water content, taken from five wells of various fields within the Bazhenov formation interval. The study reveals the temperature ranges for extracting free (121°C) and physically bound water (250°C). The measured water content of the Bazhenov formation rocks samples is 0.28-4.27 wt.% with the free water content from 0.04 to 2.53% wt. Water content decreases in carbonate interlayers and increases in the clay-rich units. We experimentally studied the effect of storage conditions and sample size on the results of water content determination. We also established that reliable water content data requires fragmenting a core sample into pieces with specific dimensions of at least 5-7 cm immediately after opening the protective shell. Comparison of water content data obtained using the Dean – Stark method and the evaporation method showed that the latter delivers much more accurate results for the oil and gas source Bazhenov formation.

References

1. Dandekar A.Y., Petroleum reservoir rock and fluid properties, Boca Raton: CRC Press; Taylor & Francis Group, 2013, 502 p.

2. Recommended practices for core analysis, Second Edition, Dallas: STEP, 1998, 220 р.

3. Kazak E.S. et al., Quantification of residual pore water content and analysis of water extract of the Bazhenov formation samples (Western Siberia) (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 4, pp. 48–52, DOI: 10.24887/0028-2448-2017-4-48-52.

4. Manual of petroleum measurement standards (MPMS), Baltimore: ASTM International, 2010, pp. 86–91.

5. Handwerger D.A. et al., Improved petrophysical core measurements on tight shale reservoirs using retort and crushed samples, SPE 147456, 2011.

6. Hensel W.M.J., An improved summation-of-fluids porosity technique, SPE 9376-PA, 1982.

7. Mackenzie R.C., Differential thermal analysis, London and New York City: Academic Press Inc., 1970, Part 1.

8. Handwerger D.A. et al., Reconciling retort versus Dean Stark measurements on tight shales, SPE 159976-MS, 2012.

9. Nutting P.G., Some standard thermal dehydration curves of minerals, Shorter contributions to general geology, 1941–1942, pp. 197–216.

10. Sondergeld C.H. et al., Petrophysical considerations in evaluating and producing shale gas resources, SPE 131768-MS, 2010.

11. Suarez-Rivera R. et al., Understanding permeability measurements in tight shales promotes enhanced determination of reservoir quality, SPE 162816-MS, 2012.

12. Wood J.M., Crushed-rock versus full-diameter core samples for water-saturation determination in a tight-gas siltstone play, SPE 174548-PA, 2015.

13. E Kazak.S. et al., Quantity and composition of residual pore water extracted from samples of the Bazhenov source rock of West Siberia, Russian Federation, Proceedings of 17th International Multidisciplinary Scientific GeoConference SGEM 2017, 29 June – 5 July, Albena: 2017,pp. 829–841.

Interpretation of electrical (EL) and electromagnetic (EML) logging is divided into two stages – the stage of geophysical interpretation and the stage of geological (petrophysical) interpretation. The stage of geophysical interpretation of logging includes a quantitative assessment of the quality of the registration curves of the complex EL and EML, point and interval interpretation (taking into account the design features of the equipment) to obtain the values of the electrical resistivity of the formation of the apparent resistance curve and the static potential of the logging curve of spontaneous polarization (PS). The result of the interpretation of the EL and EML data is the electrical resistivity of the formation, the penetration zone and the relative diameter of the penetration zone. The result of interpretation of PS logging data is the value of static potential. The stage of geological interpretation is carried out on the basis of petrophysical models of electrical resistivity and diffusion-adsorption potential of the reservoir and the values of electrical resistivity and static potential of the reservoir, obtained from the results of geophysical interpretation within the model of electrodynamics of the continuous medium.

The paper deals with the issues of automated interpretation of data of domestic and foreign complex of EL and EML, the original method of calculating the coefficient of oil and gas saturation and specific absorption capacity of clayey terrigenous reservoirs on the basis of combining the method of spontaneous polarization and methods of electrical and electromagnetic logging. The proposed method of determining the specific capacity of absorption, which is the lithological characteristics of the reservoir, and the coefficient of water saturation on the basis of integrated interpretation of spontaneous polarization method, implemented by hardware bigradient (divergent) logging of PS, and methods of EL and EML.

References

1. Chaadaev E.V., Razvitie teorii i metodiki interpretatsii dannykh elektricheskogo i induktsionnogo karotazha (Development of the theory and methodology of interpretation of electrical and induction logging data): thesis of doctor of technical science, Tver', 1991.

2. Shein Yu.L., Pavlova L.I., Rudyak B.V., Snezhko O.M., Evaluation of geoelectrical characteristics (of the formations exposed by wells) based on well logging data from different-type electric logging sondes (LOGWIN-EL) (In Russ.), Karotazhnik, 2009, no. 5, pp. 89–100.

3. Metodicheskie rekomendatsii po podschetu zapasov nefti i gaza ob’emnym metodom. Otsenka kharaktera nasyshchennosti po dannym GIS (Guidelines for the calculation of reserves of oil and gas by volumetric method. Assessment of the nature of saturation according to well logging): edited by Petersil’e V.I., Poroskun V.I., Yatsenko G.G., Moscow – Tver: Publ. of VNIGNI, 2003. 261 p.

4. Pantyukhin V.A., Shein Yu.L., Nadezhnost' opredeleniya UES plastov i vozmozhnosti ee povysheniya (Reliability of determination of resistivity layers and the possibility of its increase), Collected papers “Sovershenstvovanie tekhnologii interpretatsii i petrofizicheskogo obespecheniya geofizicheskikh issledovaniy neftegazorazvedochnykh skvazhin” (Improving the technology of interpretation and petrophysical support of geophysical studies of oil and gas exploration wells): edited by Yatsenko G.G. et al., Tver': GERS Publ., 1992, pp. 52–61.

5. Shein Yu.L., Pantyukhin V.A., Kuz'michev O.B., Algoritmy modelirovaniya pokazaniy zondov BKZ, BK, IK v plastakh s zonoy proniknoveniya (Algorithms for modeling the readings of logging probes in reservoirs with a penetration zone), Collected papers “Avtomatizirovannaya obrabotka dannykh geofizicheskikh i geologo-tekhnologicheskikh issledovaniy neftegazorazvedochnykh skvazhin i podschet zapasov nefti i gaza s primeneniem EVM” (Automated data processing of geophysical and geological and technological studies of oil and gas exploration wells and the calculation of oil and gas reserves using computers), Kalinin: Puvl of Mingeo SSSR, 1989, pp. 75–81.

6. Vendel'shteyn B.Yu., Ellanskiy M.M., Effect of rock adsorption properties on the dependence of relative resistance on porosity coefficient (In Russ.), Prikladnaya geofizika, 1964, V. 40, pp. 181–193.

7. Waxman M.N., Smits L.J.M., Electrical conductivies in oil-bearing shaly sand, SPE SPE-1863-A, 1968, https://doi.org/10.2118/1863-A

8. Clavier S., Coates G., Dumanoir J., Theoretical and experimental bases for the dual-water model for interpretation of shaly sands, SPE 6859-PA, 1984, https://doi.org/10.2118/6859-PA.

9. Afanas'ev A.V., Afanas'ev S.V., Ter-Stepanov V.V., A generalized model for terrigenous granular rock conductivity and the model's test results (In Russ.), Karotazhnik, 2008, no. 12(177), pp. 36–61.

10. Smits L.J.M., SP log interpretation in shaly sands, Trans. AIME, 1968, V. 243, pp. 123–136.

11. Kuz'michev O.B., Issledovanie estestvennykh elektricheskikh poley v neftegazorazvedochnykh skvazhinakh (teoriya, apparatura, metodika, skvazhinnye ispytaniya) (The study of natural electric fields in the oil and gas exploration wells (theory, apparatus, method, well tested)), St. Petersburg, Nedra Publ., 2006, 252 p.

12. Kuz'michev O.B., Theoretical grounds of spontaneous polarization in oil and gas prospecting wells: from homogeneous to heterogeneous according to medium resistance (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2013, no. 9, pp. 37–42.

13. Shein Yu.L., Snezhko O.M., A solution of the direct and inverse problems in the spontaneous potential technique for the formation bundle. A practical application (In Russ.), Karotazhnik, 2016, no. 9(267), pp. 156–171.

14. The certificate of registration of the computer program no. 2004611119, Opredelenie podschetnykh parametrov na osnove sovmestnoy interpretatsii dannykh karotazha PS i elektrometodov GIS dlya starogo fonda skvazhin (IntREst) (Determination of calculation parameters on the basis of the joint interpretation of SP logging and electrical methods data for old wells (IntREst)), Authors: Kuz'michev O.B., Baymukhametov D.S., Livaev R.Z.

15. Kolonskikh A.V., Mikhaylov S.P., Murtazin R.R. et al., Some specific features of dielectric logging and experience of its application at oil and gas deposits in the Western Siberia (In Russ.), Neftepromyslovoe delo, 2018, no. 12, pp. 46–52.

Technologies based on conveyor principle are used in various industries. The main purpose of conveyor method is to break up a complex process into stages. Each stage involves performing the same operation, which allows reducing the time it takes to get the result. The main objective achieved by this approach is to optimize the process of continuous product creation without losing its quality. The article describes how the conveyor principle can be applied to drilling a group of horizontal wells from a well pad that is batch drilling in LLC RN-Uvatneftegas. The peculiar thing about constructing horizontal wells is that while drilling the conductor, surface casing and the production string sections, 127 mm heavyweight drill-pipes (HWDP) are used, and when drilling the liner section - 88.9 mm HWDP. This makes it necessary to change the drilling tools. Every drill tool change takes 1.8 days. When drilling several horizontal wells from a well pad, the time spent on tool changes becomes significant. The authors compare drilling schedules of four horizontal wells constructed using a traditional technology and the batch drilling technology, which enables drilling horizontal wells by sections. The data shows that the batch drilling principle can significantly reduce the time spent on jobs other than drilling. Commissioning time for wells drilled by the traditional technology and the ones using the batch drilling are estimated. It is established that when the sequential drilling method is used the first well is put into operation earlier, however, with batch drilling, commissioning time for the entire group of wells is reduced, which enables to produce additional oil. Besides, it is noted that the use of batch drilling reduces the volume of drilling mud used and eliminates the costs associated with idle time of expensive equipment (rotary-steerable systems). The main criteria applying batch drilling method for drilling horizontal wells are listed.

References

1. Povalikhin A.S., Bliznyukov V.Yu., Double-hole drilling technology (In Russ.), Stroitel'stvo neftyanykh i gazovykh skvazhin na sushe i na more, 2013, no. 9, pp. 4–10.

2. URL: https://neftegaz.ru/news/drill/200738-rn-uvatneftegaz-uspeshno-vnedril-tekhnologiyu-konveyernogo-bur...

3. URL: https://www.rosneft.ru/press/subsidiaries/item/191449/

The initial field data come from exploration wells and seismic acquisition. Later, with drilling and commencing the operating well stock, the volume of data expands mostly leading to a sufficient update of field concept. Updated data on developing targets, consequently, affect the design concepts.

White Tiger field in the South offshore of Vietnam is one of the biggest fields of South-East Asia, in terms of oil reserves. The successful development within 1986-1991 of this unique field, from the standpoint of geophysical properties, led Vietnam to the number of long-term oil-producing states of that region. Engineering of such unique and geologically complex field required phased approach, since composing and estimating the most efficient development system under initial stage was impossible due to absence of analogues in global practices.  

The article covers the engineering design concepts for “White Tiger” field in various stages, analysis of the current state and efficiency of the applied development technology, justification for the initial characteristics and selection of designed engineering cases, comparison of designed and actual development parameters of the area, justification for the long-term oil production, water injection and drilling plan, main promising trends and actions on improving the targets development. The need to update design documentation for engineering and development of White Tiger field is obvious. The design documentation defined outlook for oil production development and field construction, efficient drilling scopes, offshore construction and geotechnical activities for well production stimulation, amount of capital investments and operating costs, as well as profit margin for the upcoming years and long-term perspective. At the same time, the obtained forecast indicators required constant monitoring and, probably, an update considering new data in geology and analysis of the oil-field development. Prerequisites to this related to partial extent of field exploration and to planning of applying new process decisions.

 

 

1 Ivanov A.N., Veliev M.M., Bondarenko V.A., Historical aspects of the offshore exploratory drilling at the rise of Vietnam petroleum industry (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 4, pp. 38–43.

The method of calculation of 3D-distributions of current recoverable oil reserves of water-flooded fields and the sweep efficiency of these reserves by displacement is developed. The objects of research are deposits at late stages of development and with hard-to-recover reserves. These reserves are characterized by low rates of production and non-achievement of project oil recovery. There is a technological possibility of additional recovery of such reserves. However, the effectiveness of these technologies depends on knowledge of the structure of residual oil reserves. The problem of adequate localization of mobile reserves cannot be solved within the framework of "linear" models, in which the residual oil saturation is determined by the static distribution in the volume of the object of development and does not depend on the development systems. Experience in the development of a huge number of fields shows that the technological oil recovery factor significantly depends on the density of the well grid and the rate of selection.

The main idea of the proposed approach is the transition from the traditional concept of 3D-digital hydrodynamic modeling to the generalized concept based on idea that localization of reserves depends on the intensity of drainage, which is characterized by the corresponding capillary number. This will allow to create a digital model of localization of current oil reserves and will provide a unique opportunity to calculate the current sweep efficiency of displacement and to build maps of this parameter. The authors have implemented a method of dynamic calculation of phase permeability, developed algorithms and created software that makes it possible to use traditional linear simulators such as Eclipse to simulate nonlinear filtration processes. The authors have generalized the notion of current sweep efficiency and highlighted lessons learned and the current displacement coefficients. The article gives examples of calculations and maps of localization of reserves and coverage of oil reserves by displacement.

The transition to this new concept makes it possible to count non-draining region of oil, oil reserves them and to identify poorly drained sites areas and to develop maps. This will improve the success from drilling infilled wells and sidetracks by 10-15% (70%) and recovery factor 5-7%. For digital models of nonlinear filtration, the concept of the current sweep efficiency of displacement can be significantly expanded: it becomes possible to perform a direct calculation of the accumulated, the current sweep efficiency and their dynamics, to form new sweep efficiency maps for displacement of current oil reserves and maps of oil reserves not covered by displacement process.

References

1. Cheremisin N.A., Klimov A.A., Efimov P.A., Equilibrium geological and hydrodynamic model of the development object AS9-11 of Lyantorskoye field (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2009, no. 10, pp. 33–37.

2. Cheremisin N.A., Sonich V.P., Baturin Y.E., Medvedev N.Ya., Basic physics of increasing the efficiency of developing granulated reservoirs (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2002, no. 8, pp. 38–42.

3. Popkov V.I., Zatsepina S.V., Shakshin V.P., Using relative permeabilities dependent on capillary number in hydrodynamic models of oil and gas fields (In Russ.), Matematicheskoe modelirovanie = Mathematical Models and Computer Simulations, 2005, V. 17, no. 2, pp. 92–102.

4. Baykov V.A., Kolonskikh A.V., Makatrov A.K. et al., Development of ultra low-permeability oil reservoirs (In Russ.), Neftyanoe khozyaystvo – Oil Industry, 2013, no. 10, pp. 52–56.

5. Mikhaylov N.N., Polishchuk V.I., Khazigaleeva Z.R., Modeling of residual oil distribution in flooded heterogeneous formations (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2014, no. 8, pp. 36–39.

6. Mikhaylov N.N., Ostatochnoe neftenasyshchenie razrabatyvaemykh plastov (Residual oil saturation of developed reservoirs), Moscow: Nedra Publ., 1992, 240 p.

7. Basak P., Non-Darcy flow and its implications to seepage problems, ASCE J. Irrig. Drain. Eng, 1977, V. 103, no. 4, pp. 459–473.

8. Fjelde I., Lohne A., Abeysinghe K.P., Critical Aspects in surfactant flooding procedure at mixed-wet conditions, SPE 174393-MS, 2015.

9. Kostyuchenko S.V., Direct calculation of the current sweep efficiency at geologic-hydrodynamic modeling (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2006, no. 10, pp. 112–115.

Well testing guidance document (2002) states a necessity of all producing wells transient pressure testing twice a year. In reality amount of testing significantly lower. Due to lack of information about wells and reservoir control and reservoir development regulation became almost impossible. Well interference testing is even more unique than conventional well test, but necessary for research of reservoir between wells. In this case an alternative is multi-well deconvolution that compensate in some degree lack of well testing. Bottomhole pressure and production rates history of adjacent wells gives an opportunity to derive self-influence function and reaction on surrounding wells production changes. Multiwell deconvolution purpose is calculation of self-influence and interference functions. Actually deconvolution makes available pressure drawdown and interference testing without production interruption. In this case interference provides additional information. Transformed bottomhole pressure curves further processed by conventional algorithms. To derive self-influence functions and well interference functions matrix-vector form of convolution equations is applied. Due to linear form of elastic mode differential equation (piezoconductivity equation) the superposition solution principle is applicable. That’s why it is proposed to derive these functions as a sum of elementary functions, related to corresponding reservoir flow regimes. This approach was tested on artificial bottomhole pressure curve. Results of artificial and deconvoluted pressure data almost ideally matched. Also simulated and interpreted self-influence and well-interference curves of different zones parameters matched.

References

1. Buzinov S.N., Umrikhin I.D., Issledovanie neftyanykh i gazovykh skvazhin i plastov (The study of oil and gas wells and reservoirs), Moscow: Nedra Publ., 1984, 269 p.

2. Earlougher R.C. Jr., Advances in well test analysis, SPE Monograph Series, 1977, V. 5, 264 p.

3. Houze O., Viturat D., Fjaere O.S., Dynamic Data Analysis V 5.12,- Kappa Engineering, 2017, 743 p.

4. Cumming J.A., Wooff D.A., Whittle T., Gringarten A.C., Multiwell deconvolution, SPE 166458-PA, 2014,

https://doi.org/10.2118/166458-PA.

5. Gringarten A.C., New development in well test analysis. Phase 2, London: Imperial College, 2018, 24 p.

6. Zheng Shi-Yi, Wang Fei, Multi-well deconvolution algorithm for the diagnostick, analysis of transient pressure with interference from Permanent Down-hole Gauges, SPE 121949-MS, 2009, https://doi.org/10.2118/121949-MS.

7. Wang Fei, Processing and analysis of transient pressure from Permanent Down-hole Gauges, Degree of Doctor of Philosophy, Heriot-Watt University, 2010, 235 p.

8. Gulyaev D.N., Batmanova O.V., Pulse-code test and multi-well deconvolution algorithms are new technologies for reservoir properties determination between the wells (In Russ.), Vestnik Rossiyskogo novogo universiteta. Seriya: Slozhnye sistemy: modeli, analiz, upravlenie, 2017, no. 4, pp. 26–32.

9. URL: https://sofoil.com/MRT%20report.pdf.

10. SOFOIL. Mul'tiskvazhinnye GDI. Tekhnologicheskiy obzor (SOFOIL. Multiwell hydrodynamical study. Technological review),

URL: https://docplayer.ru/79765531-Multiskvazhinnye-gdi-tehnologicheskiy-obzor.html.

New oil fields of various regions of the Earth are characterized by significantly diverse basic properties of oil and gas, and thermobaric conditions, which in most cases are substantially high (formation temperatures reach 200°C and the reservoir pressures exceed 40-50 MPa. The difficulty of obtaining information on the main properties of oil and gas, as well as the considerable complexity of the sampling of the samples and their PVT-study, determines the need to investigate the correlation relationships between the individual properties of oil and gas. The objective of this study is to obtain correlation based on neural networks for Iranian oil fields, which differ not only in terms of their thermobaric conditions, but also in the basic properties of their reservoir fluids. A new mathematical model is proposed using machine learning techniques for estimating PVT fluids properties such as bubble pressure and oil formation volume factor as a function of the solution gas-oil ratio, gas density, oil density, and temperature. The result obtained with this new approach is compared with previous published correlations. The model was based on artificial neural networks, and developed using 180 published data sets from the Iran. This improvement in PVT calculation accuracy will be of invaluable support for simulations and designs applied in Oil industry.

References

1. Aleksander I., Morton H., An introduction to neural computing, London: London: Chapman & Hall, 1990, 218 p.

2. Al-Marhoun M.A., New correlations for formation volume factors of oil and gas mixtures, J. Can. Pet. Technol., 1992, V. 31, pp. 22–26.

3. Al-Marhoun M.A., Evaluation of empirically derived PVT properties for Middle East crude oils, J. Pet. Sci. Eng., 2003, V. 42, pp. 209–221.

4. Standing M.B., A pressure-volume-temperature correlation for mixtures of California oils and gasses, In: Drilling and Production Practice, Tulsa: American Petroleum Institute, 1947, pp. 275–278.

Successful development of low-permeability gas-condensate reservoirs requires to apply effective digital technologies at the level of reservoir management, surface infrastructure, processing. It is extremely important to harmonize whole the production system in safe and efficient manner. Promptness of taking right decision at proper timing is crucially important here.

According to authors’ and worldwide experience, relaying to scientific knowledge we see good perspectives in intellectualization or implementation of “digital gas field” leading to higher economical effectiveness of business processes. Most effective tools are: intellectual indexing of unstructured information, measurement systems’ self-diagnosis patterns, primary data and models verification, harmonization of integrated models and telemechanic systems, machine e-learning, optimization of technological processes. Successful utilization of these tools allows for true “digitalization of field” and to achieve strong results. The authors give a review of technical solutions necessary for automation and gas field intellectualization. The core asset of ROSPAN INTERNATIONAL (subsidiary company of Rosneft Оil Company) - digital gasfield with high level of data integration is a rare case of such advancements in Russia. The authors propose the concept of data processing and measurement hardware which are now being under development in Rosneft Oil Company on the basis of ROSPAN INTERNATIONAL. Described experience shall be of interest for professionals who are involved in advanced field development planning and operation on gas-condensate fields.

References

1. Khamzin T., Reitblat E., Lomukhin A., Study of vertical and areal heterogeneity of gas composition in a gas condensate field using numerical simulation model (In Russ.), SPE 187813-RU, 2017, https://doi.org/10.2118/187813-RU

2. Saputelli L. et al., Best practices and lessons learned after 10 years of digital oilfield (DOF) implementations, SPE 167269-MS, 2013, https://doi.org/10.2118/167269-MS.

3. Pchel'nikov R.L., Mironov D.V., Muslimov E.Ya., Shevchenko S.D., Real-time well monitoring and analysis system - an element of the “Smart field” concept (In Russ.), Inzhenernaya praktika, 2011, no. 5, pp. 90-93.

4. Saputelli L. et al., Promoting real-time optimization of hydrocarbon producing systems, SPE 83978-MS, 2003, https://doi.org/10.2118/83978-MS.

5. Ignat'ev A. et al., The features of building the integrated model for development of two gas-condensate formations of Urengoyskoe field (In Russ.), SPE 166892-RU, 2013, https://doi.org/10.2118/166892-RU.

6. Bikbulatov S. et al., Optimization of operation of the system reservoir-well-pipeline-GTU based on the integrated modeling (In Russ.), SPE 171220-RU, 2014, https://doi.org/10.2118/171220-RU

7. Davidovskiy A., Abramochkin S., Lopatina N., Multiphase gas-condensate metering tests with individual fluid properties model (In Russ.), SPE 187753-RU, 2017, https://doi.org/10.2118/187753-RU

8. Lomukhin A.Yu., Cheremisin A.N., Toropetskiy K.V., Ryazantsev A.E., System of distributed monitoring of productive parameters of producing wells (In Russ.) Vestnik TsKR Rosnedra, 2013, no. 4, pp. 30-37.

9. Lomukhin A., Romashkin S., Rymarenko K., Afanasiyev V., Experience of multiphase flow measurement systems application in Arctic conditions (In Russ.), SPE 149922-RU, 2011, https://doi.org/10.2118/149922-RU.

10. Patent no. A201700544A1, A method for determining downhole parameters multicomponent stream, Inventors: Lomukhin A.Yu., Ul'yanov V.N., Toropetskiy K.V., Ryazantsev A.E., Verkhushin I.A., Taylakov D.O.

Today, the dual completion of wells with sucker-rod pumping units has become widespread, which allows to significantly increase the technical and economic efficiency of development by combining the facilities in operation. The peculiarities of mechanized oil production in this category of wells are due to a number of common complications arising during the operation and contributing to an increase in the intensity of pumping equipment operation and a decrease in the turnaround time, a decrease in well flow, which leads to a decrease in the efficiency of production in general. In these conditions, the most important tasks of cost-effective development are maintaining in working condition and ensuring optimal operating conditions for pumping equipment.

The article presents a mathematical model of a sucker-rod pumping unit for the dual completion, taking into account complications in the operation of downhole equipment. The proposed model due to a detailed account of the mechanism of formation of downhole processes allows to simulate the effect of complicating factors, such as the effect of gas, high viscosity of pumped products, leaks in valves, etc. By modeling the dynamograms, considering complications and malfunctions in the operation of the pumping unit, the analysis of the influence of complicating factors on the configuration of the model dynamograms was carried out. The proposed mathematical model can be used as a tool for diagnosing the technical condition of sucker-rod pumping units from the actual dynamogram by comparing it with the model ones.

References

1. Ibragimov N.G., Fadeev V.G., Zabbarov R.G. et al., New technology of dual-completion operation, developed in Tatneft OAO (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2008, no. 7, pp. 79–81.

2. Nurgaliev, A.A., Khabibullin L.T., Analysis of the efficiency of simultaneous-separate well operation in the South-East of the Republic of Tatarstan (In Russ.), Interekspo Geo-Sibir', 2016, no. 3(2), pp. 230–233.

3. Kadyrov A.Kh., Glukhoded A.V., Installations of dual production for the wells with small diameter (In Russ.), Inzhenernaya praktika, 2017, no. 6, pp. 4–11.

4. Gabert R.F., Ghneim G.J., Procedures and practices of dual completion design in Abu Dhabi, SPE 17983-PA, 1991, V. 6, no. 1, pp. 44–49, https://doi.org/10.2118/17983-PA

5. Muhammad I.K., Raymond E.P., Mohd S.J., Collaboration in extracting more oil in mature dual completion wells, SPE 124443-MS, 2009, https://doi.org/10.2118/124443-MS.

6. Swisher M.D., Wojtanowicz A.K., New dual completion method eliminates bottom water coning, SPE 30697-MS, 1995, https://doi.org/10.2118/30697-MS.

7. Patent no. 2377395 RF, MPK E 21 B 43/14, Equipment for simultaneous-separate process of two reservoirs of single well, Inventors: Garifov K.M., Ibragimov N.G., Fadeev V.G., Akhmetvaliev R.N., Kadyrov A.Kh., Rakhmanov I.N., Glukhoded A.V., Balboshin V.A.

8. Tret'yakov D.L., Results of technology implementation of simultaneous-separate production with gas exhaust system from the bottom horizon in wells of Belorusneft (In Russ.), Inzhenernaya praktika, 2016, no. 5, pp. 58–32.

9. Gaddy D.E., Dual compietions provide production alternative in Russian venture, Oil and Gas Journal, 2005, V. 103 (14), pp. 43–47.

10. Garifov K.M., Kadyrov A.H., Ibragimov N.G., Fadeev V.G., Zabbarov R.G., Advances in dual completion technology in Tatneft OAO (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2013, no. 7, pp. 44–47.

11. Garifov K.M., Tatneft: Technologies of dual completion (In Russ.), Neftegazovaya Vertikal', 2011, no. 13–14, pp. 114–117.

12. Patent no. 2221136 RF, Installation for separate operation of two formations simultaneously, Inventors: Ibragimov N.G., Garifov K.M., Fadeev V.G., Avramenko A.N., Ibatullin V.M., Valovskiy A.FI., Kadyrov A.F.

13. Valitov M.Z., Boltneva Yu.A., Ganiev T.A., Razrabotka matematicheskoy modeli rabochikh protsessov shtangovogo skvazhinnogo oborudovaniya dlya optimal'nogo soglasovaniya parametrov nasosa, skvazhiny i svoystv dobyvaemoy zhidkosti (Development of a mathematical model of working processes of barrel equipment for optimal harmonization of pump parameters, wells and properties of the extracted liquid), Collected papers “Resursovosproizvodyashchie, malootkhodnye i prirodookhrannye tekhnologii osvoeniya nedr” (Resource- reproducing, low-waste and environmental technologies for the development of mineral resources), Proceedings of International scientific and practical conference, Aktay, 2018, pp. 151–153.

14. Urazakov K.R., Bakhtizin R.N., Ismagilov S.F., Topol'nikov A.S., Theoretical dynamometer card calculation taking into account complications in the sucker rod pump operation (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2014, no. 1, pp. 90–93.

15. Urazakov K.R., Dmitriev V.V., Buranchin A.R.et al., Pump pipes deformation influence on rate of production and the interrepair period of wells (In Russ.), Neftegazovoe delo, 2009, no. 1, pp. 15–19.

A significant number of the largest oil fields in Russia are in the final stage of development, which is characterized by decrease in production volumes and increase in the share of complicated well stock. One of the most common ways to operate small-debit wells is sucker-rod pump units. In some cases the operation of rod units in complicated operating conditions is accompanied by reduction in inter-repair period of operation, increase in energy and economic unit costs during oil production. In these conditions, one of the most urgent tasks is reaching profitable development of wells through timely diagnosing the technical and working conditions of pumping equipment.

The aim of the study is to develop a new approach of diagnosing the condition of sucker-rod pump units on dynamogram. It is based on solving the reverse problems of the dynamics of the rod units by multidimensional optimization methods. The direct problem solution includes modeling the rod unit on the specified technological and geological and technical parameters and building the appropriate theoretical dynamogram. The inverse problem means defining the desired parameters of the model with taking into account the actual dynamogram of the rod unit. A method and an appropriate algorithm for diagnosing the condition of sucker-rod pumping units on dynamogram have been developed based on the Levenberg – Marquardt method for multidimensional optimization. The method includes quantifying the total values and parameters that characterize technical and working conditions of the rod unit, as well as complications and malfunctions that occur during its operation. There are examples of solving quantitative diagnostics tasks based on the developed algorithm by analyzing the configuration of dynamograms and constructing targeted functions under different operation conditions of pumping equipment (i.e. normal operation, high gas content at the pump suction, high landing of the plunger in the cylinder).

References

1. Aliev T.A., Rzayev A.H., Guluyev G.A., Alizada T.A., Rzayeva N.E., Robust technology and system for management of sucker rod pumping units in oil wells, Mechanical Systems and Signal Processing, 2018, V. 99, pp. 47-56.

2. Sadov V.B., The approach to definition of defects of sucker rod pump on dinacard (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 2, pp. 90–93.

3. Kovshov V.D., Sidorov M.E., Svetlakova S.V., Dynamometry, modelling and diagnostic the condition of rod pump (In Russ.), Izvestiya vuzov. Neft' i gaz, 2011, no. 3, pp. 25–29.

4. Li K., Han Y., Wang T., A novel prediction method for down-hole working conditions of the beam pumping unit based on 8-directions chain codes and online sequential extreme learning machine, Journal of Petroleum Science and Engineering, 2018, V. 160, pp. 285–301.

5. Kuz'min A.N., Vyalykh I.A., Prediction of technical condition ofrod pumps based on neural network technology (In Russ.) Vestnik Permskogo natsional'nogo issledovatel'skogo politekhnicheskogo universiteta. Khimicheskaya tekhnologiya i biotekhnologiya = PNRPU Bulletin. Chemical Technology and Biotechnology, 2016, no. 3, pp. 9–19.

6. Virnovskiy A.S., Teoriya i praktika glubinnonasosnoy dobychi nefti (Theory and practice of bottomhole pumping), Moscow: Nedra Publ., 1971, 184 p.

7. Gibbs S.G., Neely A.B., Computer diagnosis of down-hole conditions in sucker rod pumping wells, Journal of Petroleum Technology, 1966, V. 1, pp. 93–98.

8. Chen Z., White L.W., Zhang H., Predicting sucker-rod pumping systems with Fourier series, SPE 189991-PA, 2018, https://doi.org/10.2118/189991-PA.

9. Bakhtizin R.N., Urazakov K.R., Bakirov R.I. et al., Method for calculating the plunger hanger in the cylinder of the sucker-rod pump (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 2, pp. 84–88.

10. Hansen V., Tolbert B., Vernon C., Hedengren J.D., Model predictive automatic control of sucker rod pump system with simulation case study, Computers and Chemical Engineering, 2019, V. 121, pp. 265–284.

11. Bakhtizin R.N., Urazakov K.R., Ismagilov S.F., Topol'nikov A.S., Davletshin F.F., Dynamic model of a rod pump installation for inclined wells, Socar Proceedings, 2017, no. 4, pp. 74–82.

12. Urazakov K.R., Bakhtizin R.N., Ismagilov S.F., Topol'nikov A.S., Theoretical dynamometer card calculation taking into account complications in the sucker rod pump operation (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2014, no. 1, pp. 90–93.

13. Brill J.P., Mukherjee H., Multiphase flow in wells, Society of petroleum engineers: Richardson, Texas, 1999, 384 p.

14. Xiancheng Sh., Yucheng F., Jinsong Z., Kefu Ch., Chaos time-series prediction based on an improved recursive Levenberg – Marquardt algorithm, Chaos, Solitons & Fractals, 2017, V. 100, pp. 57–61, DOI: 10.1016/j.chaos.2017.04.032.

15. Urazakov K.R., Belov A.E., Davletshin F.F., Dynamic model of a rod pump installation for dual completion (In Russ.), Problemy sbora, podgotovki i transporta nefti i nefteproduktov, 2018, no. 3, pp. 33–41.

Performance efficiency of rod units, which are widely used all over the world for artificial oil lifting, depends to a large extent on feasible layout engineering of rod string, performing drive of reciprocal movement from pump motor to sucker-rod plunger. Steel is usually used as a material for production of sucker rod. However, application of steel sucker rods could lead to efficiency decrease due to the increased sucker-rod string total weight and increased pump motor load if increase in the length of rod string is required (due to lower formation pressure and the necessity of deep-laying deposits extraction). Taking into account this facts, electrical centrifugal pump plants are used in all Russian oil fields with deep wells, including stripped wells. Reaching cost-efficient deep well development could be achieved by application of composite pump rods made of fiberglass, which allow to significantly decrease load on pumping outfit and pumping motor thanks to much lower weight, higher strength and corrosion resistance.

The article presents mathematical model of the unit with combined rod string, which includes steel and fiberglass pump rod. Calculations of dynamic distortions and force were conducted during work process of rod unit with steel and combined strings in the well with low-viscous pumped out liquid. The results shows that rod string efficiency increases when pump with small diameter landing depth increases. Areas of resonant vibration response for rod string, which lead to increase of rod string vibration amplitude and effective plunger stripping thanks to coalescence of beam oscillation frequency with self-resonant frequency of rod string, were defined. The simulation showed that the most rational is pre-resonant frequency mode when reciprocating speed was almost as high as (but not lower than) resonant frequency. This operation mode makes it possible not only to reach effective plunger stripping thanks to the growth of dynamic distortions, but also to decrease the level of maximum and presented loads in rod string and loads on sucker- rod pump motor thanks to significant decrease of rod string weight.

References

1. Gibbs S.G., Application of fiberglass sucker rods, SPE 20151-PA, 1991, https://doi.org/10.2118/20151-PA.

2. Tripp H.A., Mechanical performance of fiberglass sucker-rod strings, SPE 14346-PA, 1988, https://doi.org/10.2118/14346-PA.

3. Ruidong Zhao, Xishun Zhang, Zhen Tao et al., The research and application of carbon fiber rods in deep oil wells of Xinjiang oilfield, China, SPE 184203-MS. – 2016, https://doi.org/10.2118/184203-MS.

4. Hu Yewen, Guo Jianshe, Feng Ding et al., Performance and application of fiber glass sucker rod, Oil Field Equipment, 2010, V. 39(1), pp. 35–38.

5. Zheng Jinzhong, Jiang Guangbin, Wang Xiangdong et al., Study on application of fiber glass sucker rod in offshore separate-layer water injection wells, Oil Field Equipment, 2010, V. 39(9), pp. 55–57.

6. Cen Xueqi, Wu Xiaodong, Gaofei et al., Optimization of fiber glass and steel composite rod design, Oil Field Equipment, 2012, V. 41(5), pp. 31–35.

7. Vasserman I.N., Shardakov I.N., Vasserman H.H., Dynamics of glass-reinforced plastic and combined rod columns (In Russ.), Problemy mashinostroeniya i nadezhnosti mashin = Journal of Machinery Manufacture and Reliability, 2009, no. 1, pp. 35–39.

8. Bakhtizin R.N., Urazakov K.R., Ismagilov S.F. et al., Dynamic model of a rod pump installation for inclined wells, Socar Proceedings, 2017, no. 4, pp. 74–82.

9. Urazakov K.R., Bakhtizin R.N., Ismagilov S.F., Topol'nikov A.S., Theoretical dynamometer card calculation taking into account complications in the sucker rod pump operation (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2014, no. 1, pp. 90–93.

10. Sedov L.I., Mekhanika sploshnoy sredy (Continuum Mechanics), Part 2, St. Petersburg: Lan' Publ., 2004, 560 p.

11. Bakhtizin R.N., Rizvanov R.R., Urazakov K.R. et al., Nasosnye shtangi (Sucker Rods), Ufa. Neftegazovoe delo Publ., 2012, 80 p.

12. Takacs G., Sucker-rod pumping handbook, Elsevier Science Publ., 2015, 598 p.

13. Patent no. RU2527278C1, Polydicyclopentadiene-based composite material, composition for producing matrix and method of producing composite material, Inventors: Afanas'ev V.V., Alkhimov S.A., Bespalova N.B., Zemtsov D.B., Masloboyshchikova O.V., Cheredilin D.N., Shutko E.V.

Attempts to describe the fluid flow through pipes were made by domestic and foreign scientists at different times. The article provides an overview of scientific papers in the field of hydraulic studies of pipelines published in the XVIII – XX centuries, based on processing the results of a wealth of experimental data obtained for various hydrodynamic conditions. A significant role was played by work of the French school representatives H. Darcy and G. de Prony, who first demonstrated the dependence of hydraulic losses on the diameter and roughness of the inner wall of pipes. In consequence, up to the end of the 19th century, two competing scientific directions can be observed: the study of hydraulic friction at “low” and “high” fluid velocities. The beginning of the “reconciliation” of the controversial research results was laid by the works of N.P. Petrov and O. Reynolds. The limited use of empirical dependencies does not allow to extend any of the proposed formulas to the whole range of operating modes of pipelines. For each particular case, it is necessary to analyze the accuracy of the equations used by comparison with actual operation data. A retrospective analysis of the scientific and technical literature in the field of pipeline’s hydraulics reveals the variability of methodological approaches and formal decisions in the study of quantitative estimates of the parameters of fluid flow in pipes. It was shown that the concept of using the relative roughness of the inner wall of the pipe D/D as an adaptive factor in determining hydraulic losses in pipes can be traced from Darcy’s works and has gained its methodological substantiation in the works of L. Prandtl’s school.

References

1. Kutukov S.E., Razrabotka metodov funktsional'noy diagnostiki tekhnologicheskikh rezhimov ekspluatatsii magistral'nykh nefteprovodov (Development of methods for functional diagnostics of technological modes of trunk pipelines operation): thesis of doctor of technical science, Ufa, 2003.

2. Shammazov A.M., Kutukov S.E., Arsent'ev A.A. et al., Complex investigation of rheological and adhesion properties of oils in the range of crystallization temperatures (In Russ.), Izvestiya vysshikh uchebnykh zavedeniy. Neft' i gaz, 1998, no. 4, pp. 63–72.

3. Brot R.A., Kutukov S.E., Determination of rheophysical parameters of gas-saturated oil (In Russ.), Elektronnyy nauchnyy zhurnal Neftegazovoe delo, 2005, no. 2, URL: http://ogbus.ru/files/ogbus/authors/Brot/Brot_1.pdf.

4. Al'tshul' A.D., Gidravlicheskie soprotivleniya (Hydraulic resistance), Moscow: Nedra Publ., 1982, 224 p.

5. Brown G.O., The history of the Darcy-Weisbach equation for pipe flow resistance, Proceedings of 150th Anniversary Conf. Environmental and water resources history of ASCE Reston, 2002, pp. 34–43, DOI: 10.1061/40650(2003)4.

6. Chernikin V.I., Gidravlicheskie soprotivlenia svarnykh truboprovodov (Hydraulic connections of welded pipelines), Proceedings of Oil industry academy, 1956, v. 3, pp. 53–56.

7. Isaev I.A., Eksperimental'noe opredelenie koeffitsientov gidravlicheskikh soprotivleniy v pryamykh nefteprovodnykh trubakh i fitingakh (Experimental determination of hydraulic resistance coefficients in straight oil pipelines and fittings), In: Voprosy transporta, khraneniya nefti i mashinostroeniya (Problems of transport, storage of oil and engineering), Proceedings of MOI, V. 17, Moscow: Gostoptekhizdat Publ, 1956, pp. 112–168.

8. Frenkel' N.Z., Gidravlika (Hydraulics), Moscow – Leningrad: Gosenergizdat Publ., 1956, 456 p.

9. Lobaev B.N., Novye formuly dlya rascheta trub v perekhodnoy oblasti (New formulas for calculating pipes in the transition area), Moscow: Sanitarnaya tekhnika Publ., 1954, 121 p.

10. Filonenko G.K., Pipeline hydraulic resistance (In Russ.), Teploenergetika, 1958, Vfi 4, pp.63–68.

11. Konakov P.K., New formula for hydraulic resistance coefficients for smooth pipes (In Russ.), DAN SSSR, 1946, no. 10, pp. 70–77.

12. Churchill S.W., Empirical expressions for the shear stress in turbulent flow in commercial pipe, AIChE Journal, 1973, V. 19, pp. 375–376.

13. Nikolaev A.K., Bykov K.V., Malarev V.I., Determination of the hydraulic resistance coefficient of the main oil pipeline (In Russ.), Gornyy informatsionno-analiticheskiy byulleten', 2013, no. 5, pp. 265–268.

14. Prandtl L., Tietjens O.J., Hydro und aeromechanic, Berlin: Springer-Verlag, 1934, 290 p.

15. White F.M., Fluid mechanics, 3rd ed., New York: Mc-Graw Hill, 1994, 736 p.

16. Rouse H., Ince S., History of hygraulics, lowa City: lowa Institute of Hydraulic Research, Univ. of lowa, 1957, 269 p.

17. Revel'-Muroz P.A. et al., Assessing the hydraulic efficiency of oil pipelines according to the monitoring of process operation conditions (In Russ.), Nauka i tehnologii truboprovodnogo transporta nefti i nefteproduktov = Science & Technologies: Oil and Oil Products Pipeline Transportation, 2019, V. 9, no. 1, pp. 8–19.

The article analyzes the impact of the oil complex on the ecosystem of the Khanty-Mansiysk Autonomous District - Yugra. Based on the analysis of statistical data, it has been established that the size of industrial development and the high degree of intensity of industrial load on natural territories adversely affect the ecological status of the Khanty-Mansi Autonomous District. The overall environmental damage, despite the recovery measures taken by oil producing companies and the environmental performance of regional environmental organizations, remains very high, and the environmental situation in the region remains tense. The main negative factors of the impact of the oil and gas complex on the ecosystem of Khanty-Mansiysk Autonomous District - Yugra are all stages of the oil production process. It is also impossible to deny the influence of the human factor and accident rate on the pipeline sections due to excessive operation and the imperfection of the corrosion protection technology. The danger lies in possible spills of oil and oil products due to depressurization of pipelines. In this case, taking into account the peculiarity of the developed territories and, in most cases, the lack of transport networks, difficulties in eliminating leaks may arise. In order to restore the damage and prevent undesirable consequences in the future, it is proposed to use alternative energy sources, in particular hybrid wind-solar installations. The possible options for the use of hybrid plants in oil production, taking into account the effectiveness of their work on the territory of the Khanty-Mansiysk Autonomous District - Yugra, are considered, and areas for reducing environmental impact are identified. It was found that the integrated use of wind and solar installations provide an adequate level of energy for the full maintenance of pipelines. In addition, there is no need to carry out along the transmission lines, which leads to a decrease in the level of waste at the time of the capital construction of oil production facilities. Thus, the use of alternative energy sources can be a promising solution to the current problem, which concerns the prevention of negative impact on the environment.

 

1Nasyrova I.V., Askarova A.M., On the rationality of applying hybrid (wind-sun) installations for service the oil industry objects (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 6, pp. 81–83.