The article is devoted to the issues of technical and economic assessment of resources and reserves of oil and gas fields. The modern geological and economic methodology for the classification of resources and reserves of natural hydrocarbons is considered. The new Russian classification makes it possible to distinguish: firstly, recoverable reserves, which include explored and studied categories, and secondly, resources, including undiscovered, prospective and forecast categories. It is assumed that the volume of hydrocarbon reserves that can be extracted from the subsoil during the period of field development should be determined on the basis of the presented express valuation methodology. The methodology allows making decisions on the introduction of oil reserves into commercial development. On the basis of the problem being solved, a risk assessment model is proposed to determine the efficiency of their extraction. The "triangular fuzzy number" of the most profitable recoverable reserves per one production well is used as an estimated indicator, as the main criterion for evaluation. The criterion is determined by calculation using the developed methodology and is estimated based on the deviation of the regulatory parameters: capital, operating costs and oil prices based on a hypothetical option. The technique is applicable at the early stages of prospecting and exploration of C1, C2 oil deposits in terms of their probabilistic characteristics, with an insufficient amount of information on geological and technological parameters. It allows you to economically evaluate oil reserves to determine the preliminary geological and economic feasibility (inexpediency) of resource development with the drilling of capital-intensive wells. The dependences of the change in the extremely profitable oil flow rates on the price level are presented, calculated for the most typical geological, technological and economic conditions for the development of productive formations in new fields of the Surgut arch. Dependencies can be recommended for practical decision-making on the feasibility of industrial development of the identified deposits at the current level of technology and production technology and current standards, taxes and prices. The developed methodology makes it possible to identify economically efficient development targets, to determine the optimal production dynamics and a strategy for the industrial development of oil fields.

References

1. Federal law of the Russian Federation of February 21, 1992 no. 2395-1 "About subsoil" (as amended on 08-12-2020). – https://normativ.kontur.ru/document?moduleId=1&documentId=395750

2. Order of Ministry of Natural Resources of Russia no. 228 of 04/11/19, "Ob utverzhdenii metodiki "Ekspress-otsenki zapasov uglevodorodnogo syr'ya" (On approval of the methodology "Express assessment of hydrocarbon reserves"), URL:  http://docs.cntd.ru/document/554691573.

3. Strategiya razvitiya mineral'no-syr'evoy bazy Rossiyskoy Federatsii do 2030 goda (Development strategy of the mineral resource base of the Russian Federation until 2030), URL: http://www.rosnedra.gov.ru/article/8743.html

4. Andreev A.F., Zubareva V.D., Sarkisov A.S., Otsenka riskov neftegazovykh proektov (Risk assessment of oil and gas projects), Moscow: Publ. of IRTs Gazprom, 2007, 260 p.

5. Bogatkina Yu.G., Application of theory of fuzzy set in automated system of technical-economic estimation of oil and gas fields (In Russ.), Avtomatizatsiya, telemekhanizatsiya i svyaz' v neftyanoy promyshlennosti, 2010, no. 9, pp. 11–14.

6. Bogatkina Yu.G., Otsenka effektivnosti investitsionnykh proektov v neftegazovoy otrasli s ispol'zovaniem mekhanizmov avtomatizirovannogo modelirovaniya (Evaluation of the effectiveness of investment projects in the oil and gas industry using automated modeling mechanisms), Moscow: Maks Press Publ., 2020, 246 p.

Despite of the fact that over the past 20 years, from 2001 to 2020, the share of oil in the global energy balance has decreased by 7,6 % and became 30,1 % in 2020, oil is still the main energy resource in the global energy sector. More than 95 % of oil is currently used for the production of fuels and lubricants, as well as for a wide range of oil refining and petrochemical products, and only slightly more than 5 % is used in the centralized power generation system. Nevertheless, a number of experts predict an imminent significant decrease in oil share in the world energy balance, basing their judgments on limited oil reserves and the expected imminent transfer of all modes of transport to other sources of energy (electricity, natural gas, hydrogen, etc.).

The carried out by the authors analysis of data on geological resources and reserves of traditional, transitional and unconventional types of oils allows to say that when using existing and promising technologies for field development oil production can last more than 120 years. Moreover, modern scientific ideas about the genesis of hydrocarbons allow to speak about the huge, practically inexhaustible reserves of hydrocarbons presence in the bowels of the Earth, the availability of which will depend on the innovative technical and technological solutions development for their search and development, as well as on the investment attractiveness of their production in industrial scale. Expectations of the energy transition may be delayed due to obvious scientific and technical problems associated with the search for new types of global energy, therefore, hydrocarbons and in particular oil may be in demand for a very long time.

 References

1. BP Statistical Review of World Energy, July 2021, URL: https://www.bp.com/en/global/corporate/energy-economics/statistical-review-of-world-energy.html.

2. Martynov V.G., Bessel' V.V., Kucherov V.G. et al., Prirodnyy gaz – osnova ustoychivogo razvitiya mirovoy energetiki (Natural gas is the basis for sustainable development of the world energy), Moscow: Publ. of Gubkin University, 2021, 173 p.

3. Order of the Ministry of Natural Resources of the Russian Federation No. 477 dated 01.11. 13. Ob utverzhdenii Klassifikatsii zapasov i resursov nefti i goryuchikh gazov (On approval of the Classification of reserves and resources of oil and combustible gases), URL: https://docs.cntd.ru/ document/499058008.

4.  Postuglevodorodnaya ekonomika: voprosy perekhoda (Post-hydrocarbon economy: transition issues): edited by Telegina E.A., Moscow: Publ. of Gubkin Russian State University of Oil and Gas, 2017, 406 p.

5. Shell Global Energy Resources database, URL: https://www.shell.com/energy-and-innovation/the-energy-future/ scenarios/shell-scenarios-energy-models/energy-resource-database.html#iframe=L3dlYmFwcHMvRW5lcmd5UmVzb3VyY2VEYXRhYmFzZS8jb3Blbk1vZGFs

6. Meyer R.F., Attanasi E.D., Freeman P.A., Heavy oil and natural bitumen resources in geological basins of the world: U.S., Geological Survey Open-File Report, 2007, V. 1084, 36 p.

7. Kutcherov V., Krayushkin V., The deep-seated abiogenic origin of petroleum: from geological assessment to physical theory, Review of Geophysics, 2010, V. 48, RG1001, DOI:10.1029/2008RG000270.

8. EIA/ARI World shale gas and shale oil resource assessment technically recoverable shale gas and shale oil resources: An assessment of 137 shale formations in 41 countries outside the United States, URL: https://www.adv-res.com/pdf/A_EIA_ARI_2013%20.World%20Shale%20Gas%20and%20Shale%20Oil%20Resource%20A....

9. Dyni J.R., Geology and resources of some world oil-shale deposits, Scientific Investigations Report 2005–5294; U.S. Geological Survey: 2006, URL: https://pubs.usgs.gov/sir/2005/ 5294 /pdf/sir5294_508.pdf.

10.  Panchenko I.V., Nemova V.D., Smirnova M.E. et al., Stratification and detailed correlation of Bazhenov horizon in the central part of the Western Siberia according to lithological and paleontological core analysis and well logging (In Russ.), Geologiya nefti i gaza, 2016, no. 6, pp. 22–34.

11. Kucherov V.G., Bessel' V.V., Challenges and risks of deep and super deep drilling (In Russ.), Burenie i neft', 2020, no. 3, pp. 12–16.

12. Bata T., Schamel S., Fusti M., Ibatulin R., AAPG EMD bitumen and heavy oil committee commodity report, 2017, 56 p, file:///C:/Users/vku/Downloads/2017-04-01-EMD-AnnualMeetingCommitteeBitumen%20(1).pdf

13. World Energy Outlook, 2015, URL: https://iea.blob.core.windows.net/assets/5a314029-69c2-42a9-98ac-d1c5deeb59b3/WEO2015.pdf.

14. Kolesnikov A.Yu., Saul J.M., Kutcherov V.G., Chemistry of hydrocarbons under extreme thermobaric conditions, ChemistrySelect, 2017, V. 2(4), pp. 1336–1352, DOI:10.1002/slct.201601123

15. Krayushkin V.A., Kucherov V.G., Klochko V.P., Gozhik P.F., Inorganic origin of petroleum: from geological toward physical theory (In Russ.), Geologicheskiy zhurnal, 2005, V. 2, pp. 35–43.

Trap magmatism is a typical feature of the ancient platforms. In the central parts of the Siberian platform magmatic formations make up 3% out of sedimentary cover. Basically, magmatic formations are represented by sills, less often – by dikes. On the area of the Srednebotuobinskoye field intrusions occur in the deposits of the Yuregin, Nizhnetolbachan, Verkhnetolbachan, and Olekminsk formations. The intrusions thickness changes from 95 up to 112 m. By the melt of the sedimentary rocks the fracture zones are generated. The intensive mud losses are often caused by such zones existence. The intrusive formations not only have a significant impact on the generation and accumulation of hydrocarbons, but also cause certain risks at various stages of the field exploration, including seismic data processing and interpretation, drilling and field development. To reduce the risks of the influence of intrusions on the field development, it is recommended to implement an integrated approach to their study, based on the analysis of all available geological and geophysical information on the area of interests. The spatial location and the shape of the intrusions have correlation with anomaly values of the gravity and magnetic fields. More detailed identification of trap intrusions in terms of stratigraphy is based on seismic and well data. The interpretation of the intrusions top and bottom allows to achieve more correct structure surfaces in the target zones. The results of the near-field transient electromagnetic sounding the results allow to determine the resistivity in the intervals of traps. Using wells drilling data we ranked the zones in terms of the degree of mud loss. The minimum resistivity values areas are more permeable and, as a result, have a greater risk of lost circulation. Based on the drilling results the conceptual geologic model is generated, which explains main reasons of the mud loss. Taking into account this model the ideas for risk minimization during drilling are suggested. Using an integrated data set of seismic, electromagnetics and drilling a qualitative predictive risk map during field development is built.

References

1. Sysoev A.P., Prikladnye zadachi kompensatsii neodnorodnosti verkhney chasti razreza pri obrabotke i interpretatsii seysmicheskikh dannykh (Applied problems of compensation of heterogeneity of the upper part of the section during processing and interpretation of seismic data), Novosibirsk: Publ. of IPGG SB RAS, 2011, р. 88.

2. Geologiya nefti i gaza Sibirskoy platformy (Oil and Gas Geology of the Siberian Platform): edited by Kontorovich A.E., Surkov V.S., Trofimuk A.A., Moscow: Nedra Publ., 1981, 552 p.

The article presents a concept to a full study of the lithological-facies conditions of the accumulation of carbonate reef sediments, replaced up the section by mixed terrigenous-carbonate coastal-marine sediments which in turn are replaced by terrigenous transitional and continental sediments. The relevance of studying Permian-Triassic deposits is obvious, since they compose one of the oil and gas complexes identified in Timan-Pechora oil and gas province. Previously, the study of Permian-Triassic complex was not carried out at the R. Trebs and A. Titov fields, as well as in the nearby areas.

This article provides a brief description of the algorithm for studying complex terrigenous-carbonate deposits of Permian-Triassic complex which include deposits of Asselian-Sakmarian stage, Artinskian and Kungurian stages, poorly defined Upper Permian complex, as well as Charkabozh suite of Lower Triassic. For the first time, for the indicated deposits, an analysis of the core material available for the deposits was carried out, maps of attributes were constructed using 3D seismic data and lithological-facies maps were constructed as well. Sediments were accumulating in different facies conditions, gradually replacing each other from marine conditions to continental ones. Asselian-Sakmarian complex was accumulating under the conditions of the carbonate platform with the development of chain-type organogenic structures. In Artinskian-Kungurian time interval the setting changed to the conditions of a mixed terrigenous-carbonate coastline where terrigenous-carbonate deposits accumulated. Upper Permian sediments were accumulating during the formation of the deltaic system. The sediments of Charkabozh formation were accumulating in continental conditions during the formation of an alluvial system of the intertwined type. The lithological typification of the section was carried out and together with the data of geophysical studies of wells and seismic survey made it possible to establish the main regularities of the deposits formation.

References

1. Dunham R.J., Ham W.E., Classification of carbonate rocks according to depositional texture, Classification of carbonate rocks, Proceedings of Symposium of American Association of Petroleum Geologists, 1962, no. 1, pp. 108–121.

2. Baraboshkin E.Yu., Prakticheskaya sedimentologiya. Terrigennye kollektory (Practical sedimentology. Terrigenous reservoirs), Tomsk: Publ. of TPU, 2011, 159 p.

3. Zhemchugova V.A., Rezervuarnaya sedimentologiya karbonatnykh otlozheniy (Reservoir sedimentology of carbonate deposits), Moscow: Publ. of EAGE, 2014, 232 p.

4. URL: https://www.google.ru/maps

5. Selley R.C., Ancient sedimentary environments and their sub-surface diagnosis, Cornell University Press,1970.

6. Logvinenko N.V., Petrografiya osadochnykh porod (s osnovami metodiki issledovaniya) (Petrography of sedimentary rocks (with the basics of research methods)), Moscow: Vysshaya shkola Publ., 1984, 416 p.

Looking for digitization of the visual luminescence-bituminological analysis (LBA), we have carried out experiments on quantitative determination of bitumoids in oil extracts by luminescence spectroscopy. A collection of Persian Gulf oil (D-3) with asphaltene content 7.6% was prepared, luminescence spectra were studied in a concentration range of 0.04–0.64 ml per 1 ml of chloroform (7–11 reference etalons). Chloroform of a spectroscopic grade was used. The luminescence spectra were measured with a Varian Cary Eclipse fluorescence spectrophotometer. A scanning range of the luminescence spectra was within 400–700 nm, an excitation wavelength – 360 nm. It was found out that for the D-3 oil, quantitative analysis by luminescence intensity was valid for concentrations of asphaltenes up to the 10th etalon (optical density of the solutions was less than 0.5), further analysis of more concentrated solutions gave errors due to high values of optical density. A valuable power-law regression of "intensity - oil concentration" was obtained. It was shown that at low optical densities of solutions, luminescence intensity is proportional to concentration of fluorescent substance (linear dependence), while the general relation is a power-law expression. Diagrams of luminescence intensity on concentration for different crude oils, published in the middle of last century with the first description of standard LBA, coincide with the experimental one. It was concluded that quantitative LBA may be implemented using modern digital luminescence spectrophotometers and portable analyzers; the operating range of the method pointing the numbers of reference etalon solutions was calculated. For condensates and light oils, the entire LBA collection may be used for quantitative analysis; for medium oils, instrumental analysis is valid within etalons 1–13; while for bitumens – only within etalons 1–7.

References

1. Baranova T.E., Il'ina A.A., Frolovskaya V.N., Rukovodstvo po metodike lyuminestsentno-bituminologicheskikh issledovaniy (Guide to the methodology of luminescent-bituminological research), Leningrad: Nedra Publ., 1966, 113 p.

2. Plotnikova I.N., Batyrbaeva R.A., Smelkov V.M., Lyuminestsentno-bituminologicheskiy analiz (Luminescence-bituminological analysis), Kazan: Publ. of Kazan University, 2015, 24 p.

3. Nedolivko N.M., Issledovanie kerna neftegazovykh skvazhin (Oil and gas wells core study), Tomsk: Publ. of TPU, 2006, 170 p.

4. Dotsenko V.V., Reznikov A.N., Kharchuk V.V., Lyuminestsentno-bituminologicheskie issledovaniya osadochnykh porod (Luminescent-bituminological studies of sedimentary rocks), Rostov-on-Don: Publ. of RSU, 2006, 19 p.

5. Evdokimov I.N., Losev A.P., Mogil'nichenko M.A., Spontaneous formation of abnormally viscous acid-in-oil emulsions in near-wellbore formation zone (In Russ.), Burenie i neft', 2017, no. 7–8, pp. 54–59.

6. Bulychev A.A., Verkhoturov V.N., Gulyaev B.A. et al., Sovremennye metody biofizicheskikh issledovaniy: Praktikum po biofizike (Modern methods of biophysical research: Workshop on biophysics): edited by Rubin A.B., Moscow: Vysshaya shkola Publ., 1988, 359 p.

7. Evdokimov I.N., Losev A.P., Vozmozhnosti opticheskikh metodov issledovaniy v sistemakh kontrolya razrabotki neftyanykh mestorozhdeniy (Possibilities of optical research methods in oilfield development control systems), Moscow: Neft’ I Gas Publ., 2007, 228 p.

8. Evdokimov I.N., Losev A.P., On the nature of UV/Vis absorption spectra of asphaltenes, Petroleum Science and Technology, 2007, V. 25, no. 1–2, pp. 55–56.

9.  Baker A., Cumberland S.A., Bradley C. et al., To what extent can portable fluorescence spectroscopy be used in the real-time assessment of microbial water quality, Science of The Total Environment, 2015, V. 532, pp. 14–19.

To build a unified exploration strategy for the license areas of Rosneft Oil Company within the Antipayutinskaya depression, specialists of Rosneft subsidiaries in the period of 2019-2020 built a geological model of the clinoform complex over an area of 12,267 km2 based on 11,270 lin. km of seismic lines, taking into account 16 wells for further exploration of promising targets and resource assessment. To achieve the main goal, a number of tasks were completed: collected, generalized, analyzed information quality and content, systematized geological and geophysical information; performed a comprehensive study of core and fluids; completed additional processing of 408 seismic lines; built a structural model of reference and target horizons based on drilling and seismic data; made a petrophysical interpretation of logging data.

When building the model, the methods of seismic facies analysis were applied to 2D seismic data, taking into account the regional scale. A conceptual model of the clinoform complex was developed, net reservoir zones were predicted, promising targets were identified, and the volumetrics and the fluid type within the region of study were analyzed. Recommendations were developed for exploration and appraisal drilling. The practical result of the work was a significant increase in the oil and gas potential of the region and an increase in the resource base within the area of Rosneft operation and in the unallocated subsoil fund. As a result Rosneft obtained the right to use subsoil for the purpose of geological exploration as well as exploration and production of hydrocarbons at the Severo-Kustarnikovy license area. Based on the results of the work performed, a new oil field, Novoognennoye, was geometrized and registered in the State Reserve Register. Application of the developed methodology over a large territory will allow to confirm the developed algorithms and potentially apply the methodology to similar reservoirs in Western Siberia. In the future, the methodology can be replicated in all subsidiaries of the Company, which will allow to interpret the prospects in a unified manner, determine the phase state, and evaluate resources, including within the unallocated subsoil fund.

References

1. Sedimentary environments: processes, facies and stratigraphy: edited by Reading H.G., Blackwell Publishing Limited, Second edition, 1986.

2. Reineck H.-E., Singh I.B., Depositional sedimentary environments: With reference to terrigenous clastics, Springer Science & Business Media, 2012, 439 p.

3. Potapova E.A., Typing of BU15-20 deposits within Srednemessoyakhsky swell based on core petrophysical analysis and facial analysis to predict net reservoir rocks (In Russ.), Neftepromyslovoe delo, 2017, no. 11, pp. 5–13.

4. Potapova E.A., Sikvens-stratigraficheskaya model' nizhnemelovogo klinoformnogo kompleksa v zone sochleneniya Srednemessoyakhskogo vala s Bol'shekhetskoy vpadinoy i prognoz strukturno-litologicheskikh lovushek (Sequence-stratigraphic model of the Lower Cretaceous clinoform complex in the zone of junction of the Srednemessoyakhsky swell with the Bolshekhetskaya depression and the forecast of structural and lithological traps): thesis of candidate of geological and mineralogical science, Tyumen, 2018, 20 p.

5. Muromtsev V.S., Elektrometricheskaya geologiya peschanykh tel – litologicheskikh lovushek nefti i gaza (Electrometric geology of sand bodies - lithological traps of oil and gas), Leningrad: Nedra Publ., 1984, 256 p.

The article clearly shows the uniqueness of each seismic survey and demonstrates the consequences of the practice of applying the principle of analogous contracts to assessing the cost of field seismic exploration. A positive effect is shown for the high-quality and timely implementation of the exploration stage, while moving away from the principle of an analogue agreement with regard to the cost of seismic exploration. Key factors are described that directly affect the speed and productivity of field observations, which is of great practical importance not only for regions with a traditionally short field season due to harsh climatic conditions, but also for regions with the ability to work throughout the year, thereby raising them efficiency to a whole new level. The nuances arising in the process of production work, both expected and unforeseen, are indicated, which should be paid close attention to when assessing the duration of the stage of field seismic exploration and the expected productivity of the projected survey. Unique software tools are considered, with the help of which the design process becomes more efficient, and the model of the upcoming survey takes into account the presented factors and nuances to the maximum, since it can take into account several variables and components at once. As a result, the implementation of measures for the accounting and assessment of the set of issues indicated in the article in practice contributes to the obtaining of the expected high quality of the recorded seismic data, remaining within the predicted time frame. At the same time, the efficiency of the results of exploration work in general increases significantly; the predictability, reliability and safety of work are significantly increased.

The paper analyzes and reviews the equipment used for dispersing and homogenizing the solid phase of drilling flushing and process fluids. It is effective to use in these processes the phenomenon of cavitation, as an intensifying factor for bringing the prepared solution to the condition, due to the destructive effects occurring in multiphase flows due to numerous microscopic water shocks - pressure surges, accompanied by the formation of shock waves and microjets of high intensity in the liquid. To implement these effects in the prepared solution, cavitation dispersers, NKD (mixers – diffuser) and NKD2 (slot) were developed. Analytical and numerical methods revealed the main regularities of the generation of cavitation in the flowing parts of the dispersants. Numerical simulation of the flow of multiphase flows by the finite element method was carried out on the Star-CCM + platform (Siemens PLM Software). The beginning of the initiation of cavitation occurs at an inlet overpressure of 0.05-0.08 MPa; at a value of 0.2-0.3 MPa, developed cavitation occurs, and the vapor-gas cavities fill the entire space of the diffuser or sheared nozzle. Full-scale samples of NKD and NKD2 were introduced into the activities of a service company that provides comprehensive services for the preparation of drilling fluids and process fluids for the construction and overhaul of wells at gas and oil fields in the Krasnodar Territory. Tests have shown that cavitation dispersants increase the speed of preparation and conditioning of clay suspensions by several times in comparison with standard mixing systems with stirrers. Time spent on mud preparation reduced to 12 h. The article also presents other results of experimental industrial tests of equipment. The obtained economic effects are confirmed by the acts of implementation.

References

1. Drilling fluids processing handbook, Oxford, UK: Elsevier Inc., 2005, 666 p.

2. Bridges S., Robinson L., A practical handbook for drilling fluids processing, Gulf Professional Publishing, 2020, 622 p.

3. Newman K., Lomond P., McCoch K., Advances in mixing technology improve drilling fluid preparation and properties, AADE 2009-NTCE-08-02, URL: https://www.aade.org/application/files/8015/7303/4619/2009NTCE-08-02_Tech_Paper.pdf.

4. Lambin A.I., Sosnovskikh M.P., Bronnikova T.P., Comparative assessment of clay yield when preparing drilling muds (In Russ.), Izvestiya Sibirskogo otdeleniya. Sektsiya nauk o Zemle RAEN, 2012, V. 40, no. 1, pp. 110–114.

5. Bulatov A.I., Makarenko P.P., Proselkov Yu.M., Burovye promyvochnye i tamponazhnye rastvory (Drill mud and cement slurry), Moscow: Nedra Publ., 1999, 424 p.

6. Bashta T.M., Rudnev S.S., Nekrasov B.B. et al., Gidravlika, gidromashiny i gidroprivody (Hydraulics, hydraulic machines and hydraulic drives), Moscow: Mashinostroenie Publ., 1982, 423 p.

7. Omel'yanyuk M.V., Pakhlyan I.A., Gidrodinamicheskie i kavitatsionnye struynye tekhnologii v neftegazovom dele (Hydrodynamic and cavitation jet technology in oil and gas business), Krasnodar: Publ. of CSTU, 2017, 215 p.

8. Omel'yanyuk M.V., Pakhlyan I.A., Technological application of cavitating jet streams in the oil and gas industry (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 11, pp. 130–133, DOI: 10.24887/0028-2448-2019-11-130-133

9. Vryzas Z., Kelessidis V.C., Nano-based drilling fluids: A review, Energies, 2017, V. 10, no. 4, pp. 540–574, DOI:10.3390/en10040540

10. Solutions for your toughest mixing applications in chemicals. Preparation of  drilling fluids,  Silverson report no. 33CA4, p. 4.

In the analysis of field development processes, methods for assessing the mutual influence of wells within one development object and a model of the connectivity of reservoir systems, including the forecast of the spread of anisotropy of the geological properties of the productive layer of the studied reservoir, are especially in demand. There are several approaches to solving this problem, but they all have their limitations of applicability. The purpose of the study is to systematize and evaluate the effectiveness of various existing mathematical models, statistical algorithms for describing the geology of the reservoir, the connectivity of reservoir systems and field development processes. The main sources for the research search were the SPE database OnePetro, as well as Russian scientific library eLibrary.ru. The main selection criterion was the presence in the publication of a description of the study of the mutual influence of wells. After the selection of duplicate publications, a search for the full texts of the selected publications was carried out using Digital Object Identifier (DOI) and in the ResearchGate social network. The section "Classical Methods and Phenomenological Approaches" includes a review of 6 publications by Russian scientists describing the applicability of approaches based on hydrodynamic modeling of the material balance method and the mutual productivity matrix. In the section describing capacitive-resistive models, an analysis of 7 sources is carried out, describing the hydrodynamic connection of wells on the basis of material balance equations. The section "Statistical Methods and Machine Learning Methods" includes the analysis of 11 sources, which describe both approaches based on time series analysis and based on machine learning algorithms (support vector machine, decision tree algorithm, etc.), neural network models. A separate section contains 6 studies based on the applicability of geostatistical methods. This section discusses, in addition to traditional cricking and coking methods, methods based on spatial statistical modeling. The analysis of the sources allowed us to draw conclusions about the most promising use of hybrid approaches, since when building a model on the entire set of related time series (well productivity dynamics), it is important to support the study with synchronous analysis to identify the characteristic patterns of both each well and the existing time lag in the resulting mutual influence wells.

References

1. Barenblatt G.I., Entov V.M., Ryzhik V.M., Dvizhenie zhidkostey i gazov v prirodnykh plastakh (Movement of liquids and gases in natural reservoirs), Moscow: Nedra Publ., 1984, 208 p.

2. Stepanov S.V., Sokolov S.V., Ruchkin A.A. et al., Considerations on mathematical modeling of producer-injector interference (In Russ.), Vestnik Tyumenskogo gosudarstvennogo universiteta. Fiziko-matematicheskoe modelirovanie. Neft', gaz, energetika = Tyumen State University Herald. Physical and Mathematical Modeling. Oil, Gas, Energy, 2018, V. 4, no. 3, pp. 146–164, DOI: 10.21684/2411-7978-2018-4-3-146-164.

3. Abidov D.G., Kamartdinov M.R., Material balance method as a primary tool for assessing the development indicators of a field site during waterflooding (In Russ.), Izvestiya Tomskogo politekhnicheskogo universiteta, 2013, V. 322, no. 1, pp. 90-96

4. Meerov M.V., Litvak B.L., Optimizatsiya sistem mnogosvyaznogo upravleniya (Optimization of multiply connected control systems), Moscow: Nauka Publ., 1972, 344 p.

5. Valko P.P., Doublet L.E., Blasingame T.A., Development and application of the multiwell productivity index (MPI), SPE-51793-PA, 2000, DOI: 10.2118/51793-PA.

6. Yudin E.V., Method for estimating the wells interference using field performance data (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 8, pp. 64-69, DOI: 10.24887/0028-2448-2018-8-64-69

7. Albertoni A., Lake L.W., Inferring interwell connectivity only from well-rate fluctuations in waterfloods, SPE-83381-PA, 2003, DOI:10.2118/83381-pa

8. Lake L. W., Liang X., Edgar T. F., Al-Yousef A., Sayarpour M., Weber D., Optimization of oil production based on a capacitance model of production and injection rates, SPE-107713-MS, 2007, DOI: 10.2118/107713-ms.

9. Gentil P.H., The use of multilinear regression models in patterned water floods: Physical meaning of the regression coefficients: MS thesis, The University of Texas at Austin, Texas, 2005, DOI: 10.26153/tsw/8138

10. Yousef A.A., Gentil P.H., Jensen J.L., Lake L.W., A capacitance model to infer interwell connectivity from production and injection rate fluctuations, SPE-95322-PA, 2006, DOI:10.2118/95322-pa.

11. Sayarpour M., Development and application of capacitance-resistive models to water/CO2 floods: Doctoral dissertation, The University of Texas at Austin, 2008, DOI: 10.13140/RG.2.1.1798.3847

12. Sayarpour M., Zuluaga E., Kabir C.S., Lake L.W., The use of capacitance–resistance models for rapid estimation of waterflood performance and optimization, Journal of Petroleum Science and Engineering, 2009, V. 69, no. 3-4, pp. 227-238, DOI: 10.1016/j.petrol.2009.09.006.

13. Khatmullin I. F., Tsanda A. P., Andrianova A. M., Budenny S. A., Margarit A. S., Lushpeev V. A., Semi-analytical models for calculating well interference: limitations and applications (In Russ.), Neftyanoe Khozyaystvo = Oil Industry, 2018, no. 12, pp. 38-41, DOI: 10.24887/0028-2448-2018-12-38-41

14. Apergis N., T. Ewing B., Payne J., A time series analysis of oil production, rig count and crude oil price: Evidence from six U.S. oil producing regions, Energy, 2015, V. 97, pp. 339-349, DOI: 10.1016/j.energy.2015.12.028

15. Frausto-Solis J., Chi-Chim M., Sheremetov L., Forecasting oil production time series with a population-based simulated annealing method, Arabian Journal for Science and Engineering, 2015, V. 40, pp. 1081-1096, DOI:10.1007/S13369-015-1587-Z

16. Suhartono D., Prastyo H., Kuswanto M., Hisyam L., Comparison between VAR, GSTAR, FFNN-VAR and FFNN-GSTAR models for forecasting oil production, MATEMATIKA, 2018, V. 34, no. 1, pp. 103–111, DOI:10.11113/matematika.v34.n1.1040

17. Albertoni A., Lake L.W., Inferring interwell connectivity only from well-rate fluctuations in waterfloods, SPE-83381-PA, 2003, V. 6, no. 1, pp. 6–16, DOI: 10.2118/83381-pa

18. Yousef A.A., Investigating statistical techniques to infer interwell connectivity from production and injection rate fluctuations: Doctoral dissertation, The University of Texas at Austin, 2006.

19.  Smith R., Mukerji T., Lupo T., Correlating geologic and seismic data with unconventional resource production curves using machine learning, Geophysics, 2018, V. 84, no. 2, pp. 39-47, DOI: 10.1190/geo2018-0202.1

20. Bansal Y., Ertekin T., Karpyn Z., Ayala L., Nejad A., Forecasting well performance in a discontinuous tight oil reservoir using artificial neural networks, SPE-164542-MS, USA, 2013, DOI: 10.2118/164542-ms.

21. Akande K., Olatunji S., Owolabi T., AbdulRaheem A., Comparative analysis of feature selection-based machine learning techniques in reservoir characterization, SPE-178006-MS, 2015, DOI: 10.2118/178006-MS

22. Liu W., Liu W. D., Gu J., Reservoir inter-well connectivity analysis based on a data driven method, SPE-197654-MS, 2019, DOI: 10.2118/197654-MS

23. Artun E., Characterizing interwell connectivity in waterflooded reservoirs using data-driven and reduced-physics models: A comparative study, Neural Computing and Applications, 2017, V. 28, no. 1, pp. 1729–1743, DOI:10.1007/s00521-015-2152-0

24. Maojun C., Fuhua S., Study on inferring interwell connectivity of injection-production system based on decision tree, Proceedings of 10th International Conference on Fuzzy Systems and Knowledge Discovery (FSKD), 2013, DOI: 10.1109/fskd.2013.6816343 

25. Kelkar M., Application of geostatistics for reservoir characterization accomplishments and challenges, Journal of Canadian Petroleum Technology, 2000, V. 39, pp. 25–29, DOI: 10.2118/00-07-DAS

26. Delfiner P., Delhomme J., Pelissier J., Application of geostatistical analysis to the evaluation of petroleum reservoirs with well logs, Proceedings of SPWLA 24th Annual Logging Symposium, 1983, June 27–30, New Orleans, LA, 1983.

27. Kammann E., Wand M., Geoadditive models, Journal of the Royal Statistical Society: Series C (Applied Statistics), 2003, V. 52, no. 1, pp. 1-18, DOI: 10.1111/1467-9876.00385.

28. Johannesson G., Cressie N., Finding large-scale spatial trends in massive, global, environmental datasets, Environmetrics, 2003, V. 15, no. 1, pp. 1-44, DOI: 10.1002/env.624

29. Zimmerman D., de Marsily G., Gotway C., Marietta M., Axness C., Beauheim R., Bras R., Carrera J. et al., A Comparison of seven geostatistically based inverse approaches to estimate transmissivities for modeling advective transport by groundwater flow, Water Resources Research, 1998, V. 39, no. 6, pp. 1373-1413, DOI: 10.1029/98WR00003

The subject of study is the oilfields located on the territory of Perm region which is one of the oldest oil production provinces in Russia. On the example of the largest Permian Oil production company LUKOIL-PERM JSC the analysis of oil production profile within 1939-2019 is performed. The purpose of work is to identify oil and gas fields and bearing complexes which are characterized by oil production increasing during the period from 2000 to 2019. As a result the main drivers of oil production growth were defined using one of the typical oilfield as the example. Authors highlighted the role of development technologies that allowed to develop poorly drained or undrained reserves. A number of factors are indicated that contributed to the formulation of integrated solutions to enhance field development through the expanded implementation of technological operations, linked with geological conditions and available technical capabilities, providing cost-effective results

Performed analysis is relied on the previous work of authors to determined of 6 time periods that characterized oil production profile behavior in perm region during the period from 1939 to 2019. The results of performed analysis is another step of authors’ in-depth investigation of the causes of oil production growth in Perm region. The further items to consider are: 1) the use of advanced well completion in the wells of Perm region oilfields: experience, tendencies and perspectives; 2) the development of green fields in Perm Region since 2000s, their contribution into the overall oil production; 3) the perspectives of the low-productive reservoirs development on the oilfields of Perm region; 4) the use of flexible reservoir management decisions in order to minimize the possible geological risks.

References

1. Voevodkin V.L., Antonov D.V., Oil production profile behavior in Perm region: tendencies and lessons learned (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2021, no. 8, pp. 44–49, DOI: 10.24887/0028-2448-2021-8-44-49

2. Voevodkin V.L., Raspopov A.V., Muzhikova L.N., Kondratʹev S.A., Application of new technological solutions in the field of oil & gas development in the oilfields of LUKOIL-PERM LLC (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2012, no. 12, pp. 104–106.

3. Voevodkin V.L., Lyadova N.A., Okromelidze G.V. et al., Experience and prospects of slim hole construction on LUKOIL-PERM oilfields (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 12, pp. 98–102, https://doi.org/10.24887/0028-2448-2018-12-98-102

4. Lyadova N.A., Yakovlev Yu.A., Raspopov A.V., Geologiya i razrabotka neftyanykh mestorozhdeniy Permskogo kraya (Geology and development of oil deposits of the Perm region), Moscow: Publ. of VNIIOENG, 2010, 355 p.

5. Urasova A.A., The main trends in the development of the oil industry in the Perm region (In Russ.), VUZ. XXI vek, 2015, no. 1(47), pp. 113-122.

6. Yushkov I.R., Experience in the application of methods for increasing oil recovery in the fields of the Perm Territory (In Russ.), Nauchnye issledovaniya i innovatsii, 2010, V. 4, no. 1, pp. 44–50.

7. Raspopov A.V., Kazantsev A.S., Antonov D.V., The influence of development monitoring on oilfield exploration effectivness on the Perm Territory (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2012, no. 6, pp. 58–61.

8. Zhigalov D.N., Beslik A.V., Mitroshin A.V., Application of the integrated model for increased efficiency of the operations of the high sulphur oil fields, SPE-201961-MS, 2020, DOI:10.2118/201961-MS

9.  Voevodkin V.L., Chertenkov M.V., New technologies in LUKOIL: from simple to complicated (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 8, pp. 62–66, https://doi.org/10.24887/0028-2448-2019-8-62-66

10. Sayfitdinova V.A., Dudareva I.K., Skorikova E.O., Multilateral well placement in carbonates of Volga-Ural region in Russia, SPE-202043-MS, 2020, DOI: https://doi.org/10.2118/202043-MS

11. Plotnikov V.V., Rehachev P.N., Barkovsky N.N., The effect of acid treatments on the bottom zone of clastic reservoir rocks of Perm region, SPE-182063-MS, 2016, DOI: https://doi.org/10.2118/182063-MS

12. Rakitin E., Ziganshin R., Novokreshchennykh D., Experience in application of hydraulic fracturing techniques in carbonate deposits at the Perm Krai, Republic of Komi and Nenets Autonomous District Fields. Ways to improve efficiency,

The purpose of scientific work is the development of range of tools and methods for the formation of opportunities rating of the Gazprom Neft, and for preparation of optimal business cases of basic production at operating fields of the Company. Due to a new approach of the assessment of oil production potential, there is an opportunity to promote an aggregate value of portfolio of Company’s Exploration and Production Unit through the development of the best complex decisions and research ways for increased efficiency of the basic production.

In this paper, the way of top-level assessment of the current state of reserves recovery considering geological and infrastructural complications, as well as technical features of well fund operating, was considered. This assessment allows to receive two rates: the rate of complexity and the rate of development, which provide an opportunity to assess not only the current state of object in general, but to use it as a factor when forecasting oil production in short and long terms. The modification of these rates allows to raise or to low the production of residual oil both on integral and experimental-industrial works levels. Automation of this module involves constant monitoring of all fields of the Company, which, in turn, allows to make a decision for the development of an additional program of well interventions techniques in time, in case of changing of actual oil production profile from the planned one. This module suggests reducing the load on product engineers and allows to present all aspects of the field (considered object) in a single format for monitoring.

References

1. Klassifikatsiya zapasov i resursov nefti i goryuchikh gazov. Normativno-metodicheskaya dokumentatsiya (Classification of reserves and resources of oil and combustible gases. Regulatory and methodological documentation), Moscow: Publ. of ESOEN, 2016, 320 p.

2. Lisovskiy N.N., Khalimov E.M., On the classification hard to recover reserves (In Russ.) Vestnik TsKR Rosnedra, 2009, no 6, pp. 33-35.

3. Kazakov A.A., Metody kharakteristik vytesneniya nefti vodoy (Methods for the characteristics of oil displacement by water), Nedra Publishing House, 2020, 276 p.

4. Dake L.P., Fundamentals of reservoir engineering, Shell Internationale Petroleum Maatschappij B. V., The Hague, The Netherlands, 1998, 498 p.

The article discusses the features of an integrated approach to the study of single reef deposits on the example of the Dfr2 reservoir of the Frasnian single reefs of the Volostnovsky license area of the Orenburg region. It is shown that the use of an integrated approach makes it possible to increase the efficiency of the single reefs development. According to numerous studies, the facies structure of reef reservoirs has been established, as well as the complex structure of the void space, which affects the choice of a rational method for exploration and development of oil deposits in these reservoirs. Already at the drilling stage, there are complications associated with the complex structure of the pore space of the productive deposit Dfr2 and the mixed type of a single reef reservoir. Various methods of eliminating complications did not lead to positive results, probably due to structural features. Also, at the stage of assessing oil reserves in reef reservoirs, a number of problems arise related to the calculation methods. The standard technique for assessing the geological reserves of Frasnian deposits of single reefs leads to an underestimation of the initial geological oil reserves, to an underestimation of the reservoir characteristics of reservoirs by geophysical studies of wells. This is confirmed by additional studies involving laboratory core tomography data for a productive formation, as well as experimental field data. The article also provides an assessment of the lithological - facies heterogeneity of the pay zone of a single reef reservoir. An array of well data was processed, where the criteria for geological and production characteristics were identified for the Dfr2 reservoir by facies reef zones. The influence of facies zoning on the development indicators for the wells of the Volostnovsky license area has been established.

The results of the research can be applied to other similar fields (deposits) for a more efficient development of reef reservoirs.

References

1. Kuz'mina V.V., Vilesov A.P., Facial heterogeneity of the Frasnian Kindelsky reef and its manifestation in the process of the oil deposit development (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2021, no. 7, pp. 49–57, DOI: 10.33285/2413-5011-2021-7(355)-49-57

2. Vilesov A.P., Nikitin Yu.I., Akhtyamova I.R., Shirokovskikh O.A., The Frasnian reefs of the Rybkinsky group: facial structure, formation stages, oil potential (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2019, no. 7, pp. 4–22, DOI: 10.30713/2413-5011-2019-7(331)-4-22

3. Shakirov V.A., Vilesov A.P., Chertina K.N. et al., Oil reserves distribution in complicatedly-built fractured collectors of the Frasnian reefs of Volostnovsky area in Orenburg region (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2019, no. 5(329), pp. 13–21, DOI: 10.30713/2413-5011-2019-5(329)-13-21

4. Kuz'mina V.V., Novaya tekhnologiya likvidatsii pogloshcheniy v karbonatnykh kollektorakh (na primere Kuleshovskogo mestorozhdeniya PAO “NK “Rosneft'”) (New technology for liquidation of losses in carbonate reservoirs (on the example of the Kuleshovskoye field of Rosneft Oil Company)), Proceedings of VI International (XIV All-Russian) scientific and practical conference “Neftepromyslovaya khimiya” (Oilfield chemistry), 2019, pp. 6–9.

5. Petrov V.S., Razrabotka tekhnologii i materialov, obespechivayushchikh povyshenie kachestva tamponazhnykh rabot v slozhnykh gorno-geologicheskikh usloviyakh (Development of technology and materials to improve the quality of plugging operations in difficult mining and geological conditions): thesis of candidade of technical science, Orenburg, 2013.

6. Kuz'mina V.V., A comprehensive approach to studying reef masses (on the example of fields in the Orenburg region) (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2020, no. 11, pp. 4–8, DOI: 10.30713/2413-5011-2020-11(347)-4-8

7. Kotenev Yu.A., Otsenka raspredeleniya ostatochnykh zapasov s tsel'yu povysheniya effektivnosti vyrabotki zalezhey nefti v karbonatnykh kollektorakh (na primere mestorozhdeniy yuga Bashkirii) (Assessment of the distribution of residual reserves in order to improve the efficiency of the production of oil deposits in carbonate reservoirs (on the example of fields in the south of Bashkiria): thesis of candidate of geological and mineralogical science, Ufa, 1991.

8. Patent RU 2 606 894 C1, Method for development of oil deposits confined to reef reservoirs, Inventors: Brilliant L.S, Evdoshchuk P.A., Kusner D.D.

Rosneft Oil Company pays special attention to the application of a systematic approach to find the most effective methods of enhanced oil recovery (EOR). This article is devoted to the development of a procedure for the selection of deposits and fields favorable for gas EOR methods application in a large operating company with a large number of license areas A sufficient number of geological and physical criteria for the use of gas EOR methods are given in the world technical literature. However, as a more thorough study shows, they are mainly given for successful projects. Unsuccessful projects are often silenced or there is not any explication of low-performing. In addition, the range of reservoir properties during the actual testing of EOR methods is quite wide, and the factorial study of the influence of geological and physical conditions on the effectiveness of gas EOR is extremely low. The statistics of successful gas projects did not reveal strictly significant filtration properties affecting the efficiency of gas injection, but only indicates a wide range of applicability. The authors proposed a number of key geological and physical parameters that affect the efficiency of gas exposure processes. The main selection criterion is the technical and economic efficiency of the use carbon dioxide, hydrocarbon, flue gases and nitrogen for water alternated gas injection. The procedure is based on the results of the analysis of the world experience in the use of gas EOR projects, processing of accumulated experimental studies and numerical calculations on a sector composite model. It includes several steps: 1) the search for the threshold of the minimum required amount of oil and gas in the field based on the implementation of consolidated economic assessments; 2) the identification and consideration of geological, physical and technological stop-factors that hinder the effective use of gas methods; 3) ranking of the remaining deposits based on the introduced criterion of proximity of reservoir pressure to the minimum mixing pressure; 4) clarification of economic estimates of the use of gas EOR for the company's top-priority deposits; 5) identification and consideration of technological and infrastructural risks for ranking candidates. The approach proposed by the authors has been tested at the deposits and fields of Rosneft Oil Company and will be the basis for the formation of the company's long-term plans in the field of the use of gas EOR.

References

1. Vazquez A.F., Guerrero R., Ancona M.A. et al., Immiscible nitrogen injection: a challenging experience on depleted naturally fractured reservoir, SPE-171816-MS, 2014, DOI: https://doi.org/10.2118/171816-MS

2. Heucke U., Nitrogen injection as IOR/EOR for North African oil fields, SPE–175730-MS, 2015, DOI: https://doi.org/10.2118/175730-MS

3. Taber J.J., The use of flue gas for the enhanced recovery of oil, Conference paper symposium “EOR by Gas Injection”, Int. Energy Agency Collaborative Research Program on EOR, Copenhagen, Denmark, 1988, 14 September.

4. Baykov N.M., Experience of enhanced oil recovery by CO2 injection in the U.S. fields (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2012, no. 11, pp. 141–143.

5. Balint V., Ban A., Doleshan Sh., Primenenie uglekislogo gaza v dobyche nefti (The use of carbon dioxide in oil production), Moscow: Nedra Publ., 1977, 240 p.

6. Stalkup F.I., Miscible flooding fundamentals, Society of Petroleum Engineers Monograph Series, 1983, 204 p.

7. Dindoruk B., Johns R., Orr F.M., Measurement of minimum miscibility pressure: A state of the art review, SPE–200462-MS, 2020, DOI: https://doi.org/10.2118/200462-MS

8. Christensen J.R., Stenby E.E., Skauge A., Review of WAG field experience, SPE-71203-PA, 2001, DOI: https://doi.org/10.2118/71203-PA

9. Trukhina O.S., Sintsov I.A., Experience of carbone dioxide usage for enhanced oil recovery (In Russ.), Uspekhi sovremennogo estestvoznaniya, 2016, no. 3, pp. 205–209, URL: http://www.natural-sciences.ru/ru/article/view?id=35849.

10. Juanes R., Blunt M.J., Impact of viscous fingering on the prediction of optimal WAG ratio, SPE-99721-MS, 2007, DOI: https://doi.org/10.2118/99721-MS

11. Lake L.W., Enhanced oil recovery, Englewood Cliffs, New Jersey: Prentice-Hall, 1989.

12. Piyakov G.I., Yakovlev A.P., Kudashev R.I., Romanova E.I., Study of the efficiency of WAG (on the example of the Ju1 formation of the Kogalymskoye field) (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 1992, no. 1, pp. 38–39.

13. Drozdov A.N., Telkov V.P., Egorov Ya.A. et al., Research of efficiency of high viscosity oil displacement by water-gas mixtures (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2007, no. 1, pp. 58–59.

14. Taber J.J., Martin F.D., Seright R.S., EOR screening criteria revisited. Part 1. Introduction to screening criteria and enhanced recovery field projects, SPE-35385-PA, 1997, DOI: https://doi.org/10.2118/35385-PA

15. Alkin M.Y., Hammadi E.A., First CO2 – EOR project in the Middle East, Lessons learnt and future plan after two years of injection, SPE–197274-MS, 2019, DOI: https://doi.org/10.2118/197274-MS

16. DeGolyer & MacNaughton: Otsenka proekta CO2 MUN 2020 (Assessment of the CO2 EOR project 2020) SPE, 2021.

17. Abbaszadeh M., Enhanced oil recovery methods, Publ. of Innovative Petrotech Solutions, Inc., Japan, JOGMEC, 2010.

18. Willhite G.P., Byrnes A.P., Dubois M.K. et al., A pilot carbon dioxide test, Hall-Gurney Field, Kansas, SPE-153906-PA, 2012, DOI: https://doi.org/10.2118/153906-PA

19. Zhang N., Wei M., Bai B., Comprehensive review of worldwide CO2 immiscible flooding, SPE–190158-MS, 2018, DOI: https://doi.org/10.2118/190158-MS

20. Kossack C., EOR processes – Miscible gas injection miscible CO2 and/or

H-C solvent injection, Lecture Schlumberger, SIS Training and Development, 2018.

21. Pesotskaya D.V., Fedorov M.V., Klimov M.Yu. et al., Assessment of the potential of associated gas utilization by means of gas injection technologies for the purpose of oil recovery increasing (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2013, no. 2, pp. 74–78.

22. Ignat'ev N.A., Sintsov I.A., Experience and prospects of nitrogen injection in oil&gas industry (In Russ.), Technical Sciences Fundamental Research, 2015, no. 11, pp. 43–46.

23. Nazarova L.N., Karpov S.N., Evaluation of efficiency of gas injection technology in low-permeable multiplayer objects (In Russ.), Territoriya neftegaz, 2019, no. 9, pp. 58–63.

24. Uchiyama T., Fujita Y., Ueda Y. et al., Evaluation of a Vietnam offshore CO2 Huff’n’Puff test, SPE–154128-MS, 2012, DOI:10.2118/154128-MS

25. Khan M.Y., Kohata A., Patel H. et al., Water alternating gas WAG optimization using tapered WAG technique for giant offshore Middle East oil field, SPE–183181-MS, 2016, DOI:10.2118/183181-MS

26. Zakharenko V.A., Kobyashev A.V., Fedorov K.M. et al., A forecast of the minimum mixture pressure based on the correlations equations and determination of the optimal component composition for achievement of mixing displacement in the geological conditions of the fields in the Western and Eastern Siberia (In Russ.), Neftepromyslovoe delo, 2019, no. 11 (611), pp. 62–68.

The article is devoted to the selection and application of flow redirecting technologies at the development sites of the Vankorskoye field by RN-Vankor LLC.

The first part of the article discusses the possibility of planning and applying enhanced oil recovery methods, and also analyzes the criteria for the applicability of these EOR in the conditions of the Vankorskoye field. The issues of the choice of flow redirecting technologies and their improvement are considered, taking into account a number of features, such as large compartmentalization, high permeability and permeability heterogeneity of reservoirs, as well as the development of a network of horizontal and directional wells. Shown are the results of laboratory development and pilot testing of technology based on three-dimensionally crosslinked partially hydrolyzed acrylamide polymers. Watering routes for production wells have been established. Based on the results of laboratory tests, the processing design was selected, which includes recipes for the preparation of rims and the processing sequence. Taking into account the experience of the live application of gel polymer compositions in the Vankorskoye field, the well treatment design has been improved. The technique of selection of candidate wells by the method of parametric ranking of waterflooding elements is described. The data on technological efficiency from the impact on injection wells, as well as data on the number of treatments and coverage of the fund in the implementation of the program for the use of flow diverting technologies are presented. The periods of the first tests in 2016, replication in 2017 at the Yak-3-7 deposit of the Vankorskoye field are considered.

References

1. Ganiev I.M., Yakovlev K.V., Voytov O.V. et al., Opyt primeneniya fiziko-khimicheskikh metodov uvelicheniya nefteotdachi i sovershenstvovanie potokootklonyayushchikh tekhnologiy na Vankorskom mestorozhdenii (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2021, no. 9, pp. 60–64, DOI: 10.24887/0028-2448-2021-9-60-64.

2. Mikhaylovskiy M.K., Ageev V.T., Mirgasimov R.M. et al., Investigation of factors affecting the quality of Udmurt oil treatment (In Russ.), Neftepromyslovoe delo, 1982, no. 9, pp. 74–77.

3. Igdavletova M.Z., Khlebnikova M.E., Singizova V.Kh. et al., On the mutual influence of chemicals in the technological processes of oil production (In Russ.), Neftepromyslovoe delo, 2001, no. 1, pp. 53–56.

When developing oil fields with bottomhole pressures in the wells below the saturation pressure of oil with gas, oil degassing zones will be formed in the bottomhole formation zone with different values of the phase mobility ratio, depending on the degree of bottomhole pressure decrease below the bubble point pressure. Under such operating conditions, the speed of movement of the gas phase and water will be significantly higher than the rate of oil filtration, which will lead to a decrease in the productivity index of the well. In the second half of the twentieth century, petroleum engineers, as a result of research, established the maximum permissible bottomhole pressure limit at 80% of the oil saturation pressure. In the current field development conditions, more and more production wells operate with bottomhole pressure close to the bubble point pressure, therefore, the relevance of determining the optimal bottomhole pressure relative to the bubble point pressure has significantly increased. At present, using modern means of monitoring the well operation mode, it is possible to determine this ratio in almost every field, using hydrodynamic studies of production wells equipped with an electric centrifugal pump. By changing the frequency of the electric motor using a frequency converter, and controlling the pressure at the pump intake using a thermomanometric system, it is possible to change the operating mode of the well and monitor the change in the productivity factor. As a result of the studies carried out, a limit is established for lowering the bottomhole pressure, below the saturation pressure of oil with gas, at which the maximum production rate of the production well is ensured. The article offers recommendations for maintaining a given bottomhole pressure as the main conclusions.

References

1. Nazarova L.N., Nechaeva E.V., The analysis of influence of bottomhole pressure decrease under saturation pressure on the oil recovery (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2013, no. 1, pp. 83–85.

2. Kim V.G., Baymukhametov M.A., Review of well-known methods of hydrodynamic studies of wells operating at bottomhole pressure below saturation pressure (In Russ.), Sciences of Europe, 2019, V. 45, pp. 51–57.

The oilfields of Gazpromneft-Vostok LLC are located in remote areas of the Tomsk and Omsk regions. Road transport is possible only in winter. One of the serious factor which complicating oil production at the fields of Gazpromneft-Vostok LLC is a high gas-oil ratio (GOR), in some cases the GOR can exceed 1000 m³/m³. The wells of the Urmano-Archinsk group are the most complicated by the high GOR. The number of wells with a high GOR tends to grow annually due to the drilling of new wells in the Urman-Archinsky group oilfields. At the same time, natural flowing wells are regularly converted to production by ESP, while maintaining a high GOR, which negatively affects the stable operation of the ESP. Stabilization of the ESP operation in wells with a high gas-oil ratio is an important task for the long-term operation of submersible equipment and increase oil production. One of the key factor in the stable operation of these wells is the accuracy of the selected equipment gas stabilizing device type. The geological conditions of operation of the fields of Gazpromneft-Vostok LLC force us to use a wide variety of intakes/ gas stabilizing devices to stabilize the operation of the equipment: intake, rotary gas separator, vortex gas separator, tandem gas separators, multiphase pumps, automatic diverted valve ADV. Before widespread use, the effectiveness of using additional equipment must be proven at the oilfields of Gazpromneft-Vostok LLC.  This article presents the experience of OOO Gazpromneft-Vostok in the operation of wells with a high GOR. This article shows the effectiveness of the use of multiphase pumps, advanced gas handler, and also presents the successful experience of the use of automatic diverted valve at the oilfields of Gazpromneft-Vostok LLC. Presented experience of variable-speed drive run in motor current-feedback mode.

References

1. Mishchenko I.T., Skvazhinnaya dobycha nefti (Oil production), Moscow: Neft’ i gaz Publ., 2003, 816 p.

2. Volkov M.G., Smolyanets E.F., Specifics of oil well operation in the conditions of high free gas content in the production stream (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 11, pp. 120-124, DOI: 10.24887/0028-2448-2018-11-120-124.

3. Lyapkov P.D., Metodika issledovaniya struktury potoka gazozhidkostnoy smesi v kanalakh tsentrobezhnogo nasosa (Technique for studying the structure of the flow of a gas-liquid mixture in the channels of a centrifugal pump), Proceedings of MINKh i GP, 1972, V. 99, pp. 100–106.

4. Gareev A.A., About maximum gas content on the electrical centrifugal pump (ECN) suction (In Russ.), Oborudovanie i tekhnologii dlya neftepromyslovogo kompleksa, 2009, no. 2, pp. 21–25.

5. Lyapkov P.D., Doroshchuk N.F., Zlatkis A.D., Results of tests of a submersible centrifugal pump on oil and oil and gas mixtures (In Russ.), Tatarskaya neft', 1962, no. 4.

6. Markelov D.V., Tsentrobezhnaya separatsiya gaza i tverdykh chastits v priemnykh ustroystvakh pogruzhnykh nasosnykh ustanovok dlya dobychi nefti (Centrifugal separation of gas and solid particles in the receivers of submersible pumping systems for oil extraction): Thesis of candidate of technical science, Moscow, 2007.

7. Gafurov O.G., Vliyanie dispersnosti gazovoy fazy na rabotu stupeni pogruzhnogo elektrotsentrobezhnogo nasosa (Influence of the dispersion of the gas phase on work stages of submersible electric centrifugal pump), Proceedings of BashNIPIneft', 1973, V. 34, pp. 36–49.

8. Castro M., Pessoa R., Kallas P., Successful test of new ESP technology for lake of Maracaibo Gassy oil wells, OTC 8867, 1998, DOI:10.4043/8867-MS.

9. Verbitskiy V.S., Gorid'ko K.A., Fedorov A.E., Drozdov A.N., Experimental studies of electric submersible pump performance with ejector at pump inlet when liquid-gas mixture delivering (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 9, pp. 106–109.

10. Brunet C.L., Segui E., Poseidon gas handling technology: A case study of three ESP wells in the Congo, SPE-141668-MS, 2011, DOI:10.2118/141668-MS.

11. Gi P., Buvat P., Bratu Ch., Durando P., Poseidon multiphase pump: Field tests results, OTC 7037, 1992, DOI:10.4043/7037-MS

12. Sipra I., Shotter P., Use of auto diverter valves in ESP completed oil wells which produce sand and solids, SPE-131760-MS, 2009, DOI: 10.2118/126071-MS

13. Amijaya W., Kusuma H., Narso N., Yudhanto Sudibyo G., VSD setting: ESP motor current-feedback, an effective approach to mitigate high gas interference problem in gassy ESP well, SPE-196492-MS, 2019, DOI: 10.2118/196492-MS

The article discusses the applying of an integrated approach to the planning and detailed design of the exploration well, including identifying goals and objectives, developing a decision tree, justifying the use of modern research methods and technologies, which were used to obtain the maximum possible volume of reliable geological and geophysical information and increasing the efficiency of geological exploration at a complex geological object.

The article deals with the specifics of water and gas inflow isolation processes in horizontal wells. The main causes and sources of non-target fluid inflow into horizontal boreholes and the main technologies of repair and insulation works are described. Features of the choice of technologies to restrict the flow of water and gas in horizontal wells are considered. The characteristic features of different methods of isolating compounds injection - without horizontal hole zone isolation, with the use of in-casing packers, with the use of "liquid packer" or with the installation of a "chemical plugging packer" are singled out. The success rate of water shut-off and gas shut-off technologies worldwide has been analyzed and the most effective technologies of shut-off compositions injection have been determined depending on the type of fluid to be shut-off, type of reservoir and water or gas inflow site (toe, middle or bottom of the horizontal well). Effective technologies are also divided according to the completion method: open hole, liner without or with packers, liner with flow control devices, or a cemented liner. It is also noted that in some cases the problem cannot be solved by use of chemicals and technical means or targeted search for new efficient solutions is necessary. An analysis of isolating compounds potentially highly effective in shutting off both water and gas inflows has been carried out. A polymer composition, an aluminosilicate reagent and an organosilicon compound were chosen for laboratory tests. The critical pressure gradient, which the isolating compound can withstand without being carried away from the bulk reservoir model, was taken as the main parameter evaluated to determine the effectiveness of the isolation. Another estimated parameter is residual resistance factor, which characterizes the frequency of permeability decrease of model after injection of mixture. High efficiency of polymer systems and silicone-organic compositions for water and gas isolation, as well as applicability of aluminosilicate compounds for water shut-off works were determined in the laboratory. A ranking of types of isolating compounds in terms of applicability for water or gas shut-off has been carried out. The risks and required volume of isolating agents for the treatment of extended horizontal borehole intervals were assessed. The technology of directional injection of polymer system into the target interval using two-packer arrangement was justified to isolate water inflow in conditions of high risk of gas breakthrough, and field trials were conducted - a decrease in water cut of the production was achieved.

References

1. Sun Xindi, Bai Baojun, Comprehensive review of water shutoff methods for horizontal wells, Petrol. Explor. Develop., 2017, V. 44, no. 6, pp. 1022–1029.

2. Lane R.H., Seright R.S., Gel water shutoff in fractured or faulted horizontal wells, SPE-65527-MS, 2000, https://doi.org/10.2118/65527-MS

3. Yu H., Li L., Zheng J. et al., Case study of blocking water coning in horizontal well for steam stimulation in heavy oil reservoir, SPE-182391-MS, 2016, DOI: https://doi.org/10.2118/182391-MS

4. Al-Muntasheri G.A., Sierra L., Garzon F. et al., Water shut-off with polymer gels in a high temperature horizontal gas well: a success story, SPE-129848-MS, 2010, DOI: https://doi.org/10.2118/129848-MS

5. Zaitoun A., Kohler N., Bossie-CoD. dreanu, Denys K., Water shutoff by relative permeability modifiers: lessons from several field applications, SPE-56740-MS, 1999, DOI: https://doi.org/10.2118/56740-MS

6. Shaykhulov A.M., Gilemzyanov R.M., Methods of horizontal wells operations efficiency increase at Mishkinskoye oilfield (In Russ.), Nauchno-tekhnicheskiy vestnik OAO “NK “Rosneft'”, 2013, no. 2, pp. 41–43.

7. Lightford S., Pironi E., Burrafato G., Serapiglia C.,  Solving excessive ware production in a prolific long horizontal open hole drilled in a naturally fractured carbonate reservoir, SPE-113700-MS, 2008, https://doi.org/10.2118/113700-MS

8. Al-Sharji H., Ehtesham A., Kosztin B. et al., Challenging chemical gas shut off in a fractured carbonate reservoir: case studies, SPE-112021-MS, 2008, DOI: https://doi.org/10.2118/112021-MS

9. Robertson D.B., Brown M.A., Duong L.H. et al., Coiled tubing deployed gas and water shutoffs in Alaska utilizing a polymer gel and microfine cement, SPE-173655-MS, 2015, DOI: https://doi.org/10.2118/173655-MS

10. Hupp D., Frankenburg A., Bartel P., Roberts G., Gas shutoff evaluation and implementation, North Slope, Alaska, SPE-75358-PA, 2000, DOI: https://doi.org/10.2118/75358-PA

11. Burdin K., Kichigin A., Mazitov R. et al., Gas shutoff treatment in mega rich horizontal well with coiled tubing inflatable packer for North Caspian, SPE-176688-MS, 2015, DOI: https://doi.org/10.2118/176688-MS

12. Golovanev A.S., Potryasov A.A., Kovalev V.N. et al., Unique water shut-off solution for water producing interval in a horizontal well completed with multistage fracturing system using two CT inflatable bridge plugs, SPE-171268-MS, 2014, DOI: https://doi.org/10.2118/171268-MS

13. Uddin S., Dolan J.D., Chona R.A. et al., Lessons learned from the first openhole horizontal well water shutoff job using two new polymer systems – a case history from Wafra Ratawi field, Kuwait, SPE-81447-MS, 2003, DOI: https://doi.org/10.2118/81447-MS

14. Kochetkov L., Zhurba V., Moroz V., Burdin K., Technologies from Surgutneftegaz (In Russ.), Vremya koltyubinga. Vremya GRP, 2002, no. 1, pp. 12–17.

15. Bond A.J., Blount C.G., Davies S.N. et al., Novel approaches to profile modification in horizontal slotted liners at Prudhoe Bay, Alaska, SPE-38832-MS, 1997, DOI: https://doi.org/10.2118/38832-MS

15. Nigmatullin T.E., Borisov I.M., Kornilov A.V. et al., Some aspects of filtration testing of agents for water shutoff in horizontal wells (In Russ.), Nauchno-tekhnicheskiy vestnik OAO “NK “Rosneft'”, 2012, no. 2, pp. 12–15.

The article discusses the issue of the practical implementation of various methods for calculating the quantitative values of the operating cycles of the tank of the marine terminal. The analysis of the above methods is carried out for direct and indirect calculation of the cyclicality of the sea terminal reservoir. On the basis of the performed study of various methodologies for calculating fatigue damages of structures of one type or another, as reflected in the methodological documents, a comparison and critical analysis of the results of these calculations was carried out. The contradictory and ambiguous nature of the calculation results is shown on the examples of structural steel of the tank wall of the marine terminal. The regularities of the cyclic loading of the reservoirs of the sea terminals have been determined and a method has been developed for the quantitative assessment of the parameters of the cyclic operation of the reservoirs under various modes of operation of the terminals. It is shown that the actual cyclical operation of the marine terminal reservoir, taken into account on the basis of objective data from the dispatch control and management system, differs significantly from the values obtained by any analytical methods that assess the cargo flows passing through this reservoir. The paper presents a methodology for calculating the actual and permissible number of operating cycles for a defect in the geometry of the tank wall. The proposed technique is based on formalizing real irregular loading through equivalent circuits of regular cyclicity. The scheme for determining the variants of loading blocks is presented, which allows to objectively calculate for any reservoir the number of schematization classes and the number of loading blocks. On the basis of the proposed methodology and the "rainflow method" it is possible to schematize the actual values of irregular loading and present these data in the form of schematized cycles for different filling levels corresponding to the loading units.

References

1. GOST 31385-2016. Vertical cylindrical steel tanks for oil and oil-products. General specifications, URL:  https://docs.cntd.ru/document/1200138636

2. RD 153-112-017-97. Instruktsiya po diagnostike i otsenke ostatochnogo resursa vertikal'nykh stal'nykh rezervuarov (Instructions for the diagnosis and evaluation of the residual life of vertical steel tanks), Ufa: Publ. of USPTU, 1997, 74 p.

3. SA-03-008-08, Rezervuary vertikal'nye stal'nye svarnye dlya nefti i nefteproduktov. Tekhnicheskoe diagnostirovanie i analiz bezopasnosti (metodicheskie ukazaniya) (Vertical steel welded tanks for oil and oil products. Technical diagnostics and safety analysis), Ul'yanovsk: Ul'yanovskiy Dom pechati Publ., 2009, 288 p.

4. GOST 34233.6-2017. Vessels and apparatus. Norms and methods of strength calculation. Strength calculation under low-cyclic loads, URL: https://docs.cntd.ru/document/556348918.

5. API 579-1/ASME FFS-1 2016. Fitness-for-service, URL: https://www.techstreet.com/standards/api-rp-579-1-asme-ffs-1?product_id=1924300.

6. GOST R 58622-2019. Trunk pipeline transport of oil and oil products. Methods of assessing the strength, stability and durability of vertical steel tank, URL: https://docs.cntd.ru/document/1200169167

7. Gorban' N.N., Vasil'ev G.G., Leonovich I.A., Analysis of existing approaches to modeling cyclic loading of the oil tank wall of marine terminals (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 3, pp. 110–113, DOI: 10.24887/0028-2448-2019-3-110-113

8. Gorban' N.N., Vasil'ev G.G., Leonovich I.A., Sal'nikov A.P., Study of the functioning models of tank farms of marine terminals in the Russian Federation (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2020, no. 1, pp. 77–80, DOI: 10.24887/0028-2448-2020-1-77-80

9. Gorban' N.N., Vasil'ev G.G., Leonovich I.A., The analysis of the operating mode of the large volume oil tank (In Russ.), Nauka i tehnologii truboprovodnogo transporta nefti i nefteproduktov = Science & Technologies: Oil and Oil Products Pipeline Transportation, 2019, V. 9, no. 4, pp. 394–401, DOI: 10.28999/2541-9595-2019-9-4-394-401

10. Kaspiyskiy Truboprovodnyy Konsortsium: Khronologiya proekta (Caspian Pipeline Consortium: Project timeline), URL: http://www.cpc.ru/RU/about/Pages/chronology.aspx

11. Sturges H., The choice of a class-interval, J. Amer. Statist. Assoc., 1926, V. 21, pp. 65–66.

The paper describes the challenges in integrated history matching of high-viscous oilfields. Integrated models are increasingly implemented in hydrocarbon fields development. Once the integrated model is applied within the technological process, it becomes the tool of the oil company operation. The advantage of the integrated models is confirmed by various articles in Russian and foreign research publications.  It has been confirmed, that ignoring of temperature dependencies of high-viscous oil and water-oil emulsion lead to poor history matching of the stream gathering and transportation system, especially in cold seasons. The performed studies on the integrated model of the oilfield showed significant dependency of the flow line pressure in gathering and transportation system from the ambient temperature. The fact, that the model describes gathering and transportation system behaviour very well within warm seasons and has poor history matching within cold seasons, proves the ignoring of the temperature effect. It has been described, that the temperature dependency for high-viscous oil is significant, especially in the area of low temperatures. This fact allows performing good history matching of the gathering and transportation system to the flowline pressure measurement during the cold seasons. However, without consideration of possible emulsions in some point of the gathering and transportation system, it is impossible to “fine-tune” the history matching. Even though, this assumption is hypothetical, it clearly indicates the challenging spots within the gathering system, which require additional studies for sources determination of the stream motion resistance. The adjustment of the integrated model it is necessary to understand that the matching results significantly depend on the initial data of the model update. Asynchrony in measurements, mistakes in the system operation parameters, ignored effects – all these bring the high level of uncertainty and reduce the forecast properties of the integrated model.

References

1. Apasov R.T., Chameev I.L., Varavva A.I. et al., Integrated modeling: a tool to improve quality of design solutions in development of oil rims of multi-zone oil-gas-condensate fields (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 12, pp. 46–49, DOI: 10.24887/0028-2448-2018-12-46-49

2. Ushmaev O.S., Apasov R.T., Chameev I.L. et al., Integrated modeling as a tool for evaluating the effects of well production rates and surface gathering system performance on development of oil rim (In Russ.), SPE-182007-MS, 2016, https://doi.org/10.2118/182007-MS

3. Povyshev K.I., Vershinin S.A., Vernikovskaya O.S., Integrated model "Reservoir – Well – Infrastructure" and its opportunities (In Russ.), PRONEFT''. Professional'no o nefti, 2016, no. 2, pp. 48–53.

4. Bogdanov E.V., Chameev I.L., Reshetnikov D.A. et al., Integrated modeling as a tool to increase the development efficiency of the multilayer oil-gas-condensate field (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no 12, pp. 52–55, DOI: 10.24887/0028-2448-2019-12-52-55

5. Yanochkin S.V. Rychkov A.F., Integrated modeling. Experience in operating pilot projects (In Russ.), Neft'. Gaz. Novatsii, 2018, no. 12, pp. 29–30.

6. Rychkov A.F., Kadykov I.A., Postroenie integrirovannykh modeley mestorozhdeniy s vysokoproduktivnymi skvazhinami v usloviyakh malykh znacheniy depressiy na plast na primere Pamyatno-Sasovskogo mestorozhdeniya (Construction of integrated models of fields with highly productive wells in conditions of low values of drawdowns on the reservoir using the example of the Pamyatno-Sasovskoye field), Proceedings of Konferentsiya molodykh uchenykh i spetsialistov Golovnogo ofisa LUKOYL-Inzhiniring, 2018, Moscow, 2018, pp. 664–673.

A significant item of operating costs of an oil production enterprise is the consumption of electricity to ensure the pumping of products through the field pipelines. To assess the efficiency of electricity use it is necessary to monitor the energy consumption of the technological process

This article focuses on evaluating the performance of field pipelines in terms of energy consumption. The paper presents methods for assessing the energy efficiency of the linear part of field pipelines and factor analysis of the causes of changes in energy efficiency. A modification of the equation for determining the hydraulic power losses in the pipeline to assess the energy consumption of field pipelines transporting gas-liquid mixtures is proposed. An algorithm for determining the influence of various operational factors on energy efficiency is described, and the performance and effectiveness of the factor analysis is shown on the example of an existing pipeline. Factor analysis is performed by the deterministic method of chain substitution, in which the sum of the influence of each factor individually is equal to the actual change in the analyzed value, which allows you to choose the most uncertain factor and find the impact of its changes in the amount of energy consumption by the joint value of the impact of known factors. The approaches described allow us to assess the change in the energy efficiency of the pipeline over the period under consideration, as well as to compare the level of energy consumption and energy efficiency of different pipelines among themselves, to carry out ranking of pipelines on the basis of the obtained indicators. Comparison of different pipelines can be performed by comparing the values of deviation of energy consumption from the normative or ideal, the values of each of the influencing factors, thus forming a certain information rating. Consequently, knowing the overall picture of the impact of various factors, you can determine which of them individually or in the aggregate have the greatest negative impact on the object under consideration and to assess what measures to reduce energy consumption can bring the greatest effect.

References

1. Bogdanov R.M., Calculation of standards of electric energy consumption for oil transportation via pipelines (In Russ.), Neftegazovoe delo, 2012, no. 1, pp. 47–57.

2. Kutukov S.E., Informatsionno-analiticheskie sistemy magistral'nykh truboprovodov (Information and analytical systems of trunk pipelines), Moscow: Publ. of SIP RIA, 2002, 324 p.

3. Gol'yanov A.I., Gol'yanov A.A., Kutukov S.E., Review of main pipelines energy efficiency estimation methods (In Russ.), Problemy sbora, podgotovki i transporta nefti i nefteproduktov, 2017, no. 4 (110), pp. 156–170, DOI: 10.17122/ntj-oil-2017-4-156-170.

4. Galimov R.M., Chumakov G.N., Burtasov S.E., Evaluation of energy efficiency of field well production gathering systems in CDNG no. 7 LLC "LUKOIL-PERM" (In Russ.), Vestnik Permskogo natsional'nogo issledovatel'skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Bulletin of Perm National Research Polytechnic University. Geology. Oil & Gas Engineering & Mining, 2013, no. 7, pp. 35–46, DOI:10.15593/2224-9923/2013.7.4

The object of the study is high-viscosity emulsions consisting of two immiscible liquids – oil and water. Factors affecting both the viscosity of such emulsions and the phase inversion point are considered. It was experimentally established that the phase inversion point is within the product water content from 50 to 80% and is characterized by the highest viscosity values of oil-water emulsions. However, under certain factors affecting the dispersion system, this range can increase to 85%. The influence of such parameters as water density, oil density, oil viscosity, mixing intensity, liquid shear rate, interfacial tension at the oil-water interface, acidity (pH) of the water phase on the rheological behavior of dispersed systems with respect to the displacement of the phase inversion point and the viscosity of oil-water emulsions is studied. The rheological dependences of the dynamic viscosity of oil-water emulsions on the above-mentioned factors were obtained. The factors that affect the phase inversion of dispersed systems and the value of the dynamic viscosity of oil-water emulsions are determined. The criteria for the influence of these factors on the displacement of the inversion point of the phases of the emulsions are revealed. An empirical equation is derived that takes into account the effect of the displacement of the phase inversion point as a function of the difference in the densities of oil and water. The main conclusions on the phase inversion offset are presented, which can be used to develop decision-making algorithms for predicting the phase inversion point and the dynamic viscosity of oil-water emulsions both during production and transportation, and during oil preparation.

References

1. Valiakhmetov R.I., Zdolnik S.E., Litvinenko K.V., A systematic approach to the choice of technologies for preventing complications in well oil production (In Russ.), Inzhenernaya praktika, 2016, no.4.

2. Medvedev V.F., Sbor i podgotovka neustoychivykh emul'siĭ na promyslakh (Gathering and preparation of unstable emulsions in the fields), Moscow: Nedra Publ., 1987, 144 p.

3.  Sakharov V.A., Mokhov M.A., Gidrodinamika gazozhidkostnykh smesey v vertikal'nykh trubakh i promyslovykh pod"emnikakh (Hydrodynamics of gas-liquid mixtures in vertical pipes and field hoists), Moscow: Publ. of Gubkin University, 2004, 398 p.

4. Ngan K.H., Phase Inversion in dispersed liquid-liquid pipe flow: PhD Thesis, Department of Chemical Engineering, University College London, 2010.

5. Matar O.K., Hewitt G.F., Ortiz E.S., Phase inversion in liquid-liquid dispersions, Department of Chemical Engineering, Imperial College, London.

6. Arirachakaran S., Oglesby K.D., Malinowsky M.S. et al., An analysis of oil/water flow phenomena in horizontal pipes, SPE-18836-MS, 1989, DOI: http://dx.doi.org/10.2118/18836-MS

7. Alboudwarej H., Shahraki A. et al., Rheology of heavy-oil emulsions,

SPE-97886-PA, 2007, DOI:10.2118/97886-PA

8. Wang W., W Cheng., Li K. et al., Flow patterns transition law of oil-water two-phase flow under a wide range of oil phase viscosity condition, Journal of Applied Mathematics, 2013, no. 8, pp. 1–8, DOI: http://dx.doi.org/10.1155/2013/291217.

9. Odozi U.A., Three-phase gas/liquid/liquid slug flow: PhD Thesis, Chem. Eng. Dept., Imperial College, London, UK, 2000.

10. 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. 9–31.

11. Faroughi S.A., Huber C., Crowding-based rheological model for suspensions of rigid bimodal-sized particles with interfering size ratios, Physical Review, 2014, no. 5, DOI:10.1103/PhysRevE.90.052303

12. Ioannou K., Phase inversion phenomenon in horizontal dispersed oil/water pipeline flows: PhD Thesis, London: University College London, 2006.

13. Nädler M., Mewes D., Flow induced emulsification in the flow of two immiscible liquids in horizontal pipes, Int. J. Multiphase Flow, 1997, no. 23 (1), pp. 55–68.

14. Instruction Manual HAAKE Viscotester 550,  https://archive-resources.coleparmer.com/Manual_pdfs/98941-00,10.pdf

In domestic and international regulations the calculation of pipeline durability is performed based on force criterion under stress in form of allowed limit states and allowed limit stresses. This assumes that pipeline level of defect, at the point of its installation, construction and operation, remains within the norm of flaw detection control. However, continuous practice of pipelines operation (up to 40-50 years) demonstrates that these calculations do not exclude the appearance and development of flaw and cracks with sizes not only exceeding the norms, but also leading to loss of tightness and breakdown.

This article covers the analysis problems of the most dangerous states of main oil pipelines for transportation of oil and oil products in the event of longitudinal welded cracks, leading to loss of tightness and further breakdown. Normative methods of durability main calculations based on allowed loads, combined with methods of linear and nonlinear destruction mechanics were used as a basis for analysis. For modern pipelines, manufactured from enhanced plasticity pipe steel, reaching limit states within and outside of crack area happens upon occurrence of developed plastic regions, notably altering rated and local stress strain state. Taking this into account, the necessity and possibility of using a combination of force criterion of linear breakdown mechanics - critical coefficients of load intensity, critical coefficients of deformation intensity within the system of relative parameters was justified and proposed. This allows performing calculations for cases of high rated and local deformation, exceeding elasticity limits by tens and hundreds of times. Calculations show significant increase of limit crack size after transition from brittle to ductile fractures.

References

1. Mazur I.I., Ivantsov O.N., Bezopasnost' truboprovodnykh sistem (Pipeline safety), Moscow: Nedra Publ., 2004, 1099 p.

2. Radionova S.G., Zhulina S.A., Makhutov N.A. et al., Research prospects in the field of risk analysis for improvement of government regulation and safety increase of the oil and gas chemical complex objects (In Russ.), Bezopasnost' truda v promyshlennosti, 2017, no. 9, pp. 5–13.

3. Makhutov N.A., Deformatsionnye kriterii razrusheniya i raschet elementov konstruktsiy na prochnost' (Deformation criteria for fracture and strength analysis of structural elements), Moscow: Mashinostroenie Publ., 1981, 272 p.

4. Neyber G., Khan G., Problems of stress concentration in scientific research and technology (In Russ.), Mekhanika, 1967, no. 3, pp. 96–112.

5. Lisin Yu.V., Makhutov N.A., Neganov D.A. et al., Integral mechanical tests in the strength calculations of the main pipeline for transportation of oil and oil products (In Russ.), Zavodskaya laboratoriya. Diagnostika materialov, 2018, V. 84, no. 4, pp. 47–59.

6. Makhutov N.A., Prochnost' i bezopasnost': fundamental'nye i prikladnye issledovaniya (Strength and safety: fundamental and applied research), Novosibirsk: Nauka Publ., 2008, 528 p.

7. Lisin YU.V., Makhutov N.A., Neganov D.A., Varshitskiy V.M., Comprehensive analysis of the pipelines safety and basic mechanical properties of the pipe steels (In Russ.), Nauka i tehnologii truboprovodnogo transporta nefti i nefteproduktov = Science & Technologies: Oil and Oil Products Pipeline Transportation, 2017, no. 1(28), pp. 30–38.

8. Kiefner J.F., Failure stress levels of flaws in pressurized cylinders, American society of testing and materials report, 1973, ASTM STP 536, pp. 461–481.

9. Pluvinage G., Mécanique élastoplastique de la rupture: Critères d'amorçage, Cepadues, 1989.

10 . Matvienko Yu.G., Safety factors in structural integrity assessment of components with defects, International Journal of Structural Integrity, 2013, no. 4, pp. 457–476.

11. Bezopasnost' Rossii. Pravovye, sotsial'no-ekonomicheskie i nauchno-tekhnicheskie aspekty. Bezopasnost' sredstv khraneniya i transporta energoresursov (Security of Russia. Legal, socio-economic and scientific-technical aspects. Security of energy storage and transportation facilities): edited by Makhutov N.A., Moscow: Znanie Publ., 2019, 928 p.

12. Makhutov N.A., Permyakov V.N., Resurs bezopasnoy ekspluatatsii sosudov i truboprovodov (Resource of safe operation of vessels and pipelines), Novosibirsk: Nauka Publ., 2005, 516 p.

The present paper discusses the author’s experience in development and use of a number of educational mobile applications for "Oil and Gas Engineering" subjects. Mobile devices can be easily used for educational purposes by creating a virtual educational environment due to high computing power. One can create an interactive technical process, in particular, a laboratory work on a smartphone screen. The quality of modern graphics, combined with the performance of traditional calculations, enhance the perception of educational information by the student. An additional benefit is the high availability of mobile devices. Thanks to the mobile learning application, each student gets the opportunity to understand and learn a laboratory work or other practical task using a personal phone or a tablet in a relatively short period of time. Unfortunately, nowadays higher education practically does not use the potential of mobile devices in any way. Learning subjects of oil and gas engineering profession include a large number of laboratory and calculation tasks that simulate industrial activities. A variety of tasks and their practical approach suggests a high potential for e-learning technologies. The paper discusses educational problems that can be solved by mobile applications simulating the work of laboratory instruments or a field research procedure. Such applications are called "virtual laboratories" - they allow a student to complete a technical task in a virtual environment, while each student works with his own numbers, and the application checks the student's calculations. Basic principles of application design are described in the paper. The applications are based on a numerical or analytical model. The student interacts with this model by performing actions in the application (pressing buttons or moving objects). Then student sees some parameters of the model on the phone screen – these values are perceived as real parameters of the technical process (object weight, pressure gauge readings, etc.). Finally, the student calculates hidden parameters of the model (which are the subject of verification) by processing the visible parameters. The results of students’ survey on using mobile applications in distance learning are analyzed in the end of the paper. Recommendations on the development of similar applications are given.

References

1. Mukhina A.G., Shelyago N.D., Building virtual models for monitoring technological processes of oil and gas production in the PI system environment as a learning tool for digital natives generation (In Russ.), Avtomatizatsiya, telemekhanizatsiya i svyaz' v neftyanoy promyshlennosti, 2020, no. 4(561), pp. 50–54, DOI: 10.33285/0132-2222-2020-4(561)-50-54

2. Shtyrova I.A., Vishtak N.M., Remarenko S.A., Use of the mobile application for the establishment of a higher education unit of additional education (In Russ.), Sovremennye naukoemkie tekhnologii, 2019, no. 2, pp. 153–157.

3. Dobychina S.S., Mobil'nye tekhnologii v sisteme vysshego obrazovaniya (Mobile technologies in the higher education system), Collected papers “Nauka YuUrGU” Proceedings of 69th scientific conference. Section of Economics, Management and Law, 2017, Part 1, pp. 29–34.

4. Rakhmatov V.Z., Virtual'nye laboratorii v sisteme obucheniya studentov (Virtual laboratories in the student learning system), Proceedings of Donetsk Institute of Railway Transport, 2018.

5. Duncan R., The potential contribution of augmented and virtual reality to the oil and gas industry, International Journal of Management and Applied Research, 2015, V. 2, no. 3, pp. 112–120, DOI: 10.18646/2056.23.15-011

6. Santos I.H.F., A collaborative virtual reality oil & gas workflow, The International Journal of Virtual Reality, 2012, no. 11(1), pp. 1–13, DOI: 10.20870/IJVR.2012.11.1.2832

7. Jampeisov Z., Using virtual reality technology in oil and gas industry, International Journal of Engineering and Management Research, 2019, V. 9(2), pp. 124–127, DOI: 10.31033/ijemr.9.2.15

8. Kyselova V., The benefits of VR for improving training in the oil and gas industry, URL. https://jasoren.com/the-benefits-of-vr-for-improving- training-in-the-oil-and-gas-industry/

9. Drilling simulator lab training - Module 1: Drilling operation practices, Dakota: University of North Dakota, URL: https://register.und.edu/learning/jsp/session.jsp?sessionId=EVT.18.0003&courseId=EVT.ENGR.DS...

10. Martynov V.G., Sheynbaum V.S., Pyatibratov P.V., Sardanashvili S.A., Implementing interdisciplinary education through virtual environment for design and professional tasks (In Russ.), Inzhenernoe obrazovanie, 2014, no. 14, pp. 5–11.

11. Martynov V.G., Sheynbaum V.S., Sardanashvili S.A., Pyatibratov P.V., Digital field in the education  (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2011, no. 6, pp. 124–126.

12. Hero L.M., Lindfors E., Students’ learning experience in a multidisciplinary innovation project, Education + Training, 2019, V. 61, no. 4, pp. 500–522, DOI 10.1108/ET-06-2018-0138

The process of biocorrosion of pipelines develops as a result of the influence of various factors. The process of adaptation of microorganisms to the action of individual environmental factors is quite complex and is determined by a set of parameters. The soil conditions of the pipeline route lead to active bacterial and mycological colonization. Micromycetes that are part of the microbial association can change the concentration of individual bacteria, producing antibiotic compounds, thereby changing the quantitative ratios between various representatives of the microbiocenosis. Purpose of the work was to investigate the complex of factors that make up the development of the biocorrosion process on the routes of the oil pipeline. The factors of development of corrosion are studied in the samples of soil on the routes of the oil pipeline and in control samples. Bacteriological study of soil samples made it possible to establish the qualitative and quantitative characteristics of corrosive microorganisms - sulfate-reducing and thionic bacteria. The quantitative characteristics of the identified thionic and sulfate-reducing bacteria in the pipeline route and in the control samples differed. The mycological study of the soil showed a higher quantitative content of micromycetes near the oil pipeline in comparison with the control soil samples. The level of the index of specific electrical resistance of the soil has been established, indicating the high corrosiveness of the soil and the optimal indicator of moisture for the maximum rate of underground soil corrosion. The obtained results indicate the formation of a specific soil microbiocenosis on the oil pipeline routes, represented by corrosive microorganisms - bacteria, fungi that contribute to the development of biocorrosion. The analysis of the severity of the microbiological indicators of the soil indicates the need to introduce additional research methods in order to further identify the spectrum of corrosive microorganisms that cause the development of corrosion along the oil pipeline routes.

References

1. Sharkova T.V., Kutlunina N.V., Mingalev E.P., Corrosion-dangerous microflora of soils of Western Siberia oil fields (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2009, no. 8, pp. 108–111.

2. Li S., Kim Y., Jeon K., Kho K., Microbiologically influenced corrosion of underground pipelines under the disbonded coatings, Metals and Materials International, 2000, no. 6(3), pp. 281–286.

3. Ryazanov A.V., Vigdorovich V.I., Zavershinskiy A.N., The bio-corrosion of metals. Theoretical principles. Methods of depression (In Russ.), Vestnik Tambovskogo universiteta. Seriya: Estestvennye i tekhnicheskie nauki, 2003, no. 8(5), pp. 821–837.

4. Talukdar M.K., Kujur A., Bhat S., Sahota S.K., Failure analysis of an onshore pipeline in petroleum industry – A case study, SPE-155232-MS, 2012, https://doi.org/10.2118/155232-MS.

5. Griban'kova A.A., Myamina M.A., Beloglazov S.M., Microbiological corrosion of soft steel in water-salt medium containing sulfate-reducing bacteria (In Russ.), Vestnik Baltiyskogo federal'nogo universiteta im. I. Kanta, 2011, no. 7, pp. 23–29.

6. Hamilton W.A., Microbially influenced corrosion as a model system for the study of metal microbe interactions: a unifying electron transfer hypothesis, Biofouling, 2003, V. 19, no. 1, pp. 65–76.

7. Yang M., Yang Y.S., Du X., Fate and transport of petroleum hydrocarbons in vadose zone: Compound-specific natural attenuation, Water, Air & Soil Pollution, 2013, V. 224, no. 3, Article no. 1439.

8. Chesnokova M.G., Shalay V.V., Kraus Yu.A., Biocorrosion activity in soils of pipeline route in Krasnodar Region (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 5, pp. 102–105.

9. Chesnokova M.G., Shalay V.V., An actuality of soil micromyceta community studies for soil biocorrosive activity evaluation on the oil pipeline routes, AIP Conference Proceedings, 2018, V. 2007: Oil and Gas Engineering, https://doi.org/10.1063/1.5051845.

10. Chesnokova M.G., Shalay V.V., Kriga A.S., Biocorrosive activity analysis of the oil pipeline soil in the Khanty-Mansiysk Autonomous Region of Ugra and the Krasnodar Territory of the Russian Federation, AIP Conference Proceedings, 2017, V. 1876, https://doi. org/ 10.1063/1.4998839.

11. Chesnokova M.G., Shalay V.V., Aktual'nost' izucheniya soobshchestva pochvennykh mikromitsetov pri provedenii otsenki biokorrozionnoy aktivnosti pochvogrunta na trassakh nefteprovoda. Tekhnika i tekhnologiya neftekhimicheskogo i neftegazovogo proizvodstva (The relevance of studying the community of soil micromycetes when assessing the biocorrosive activity of soil along the oil pipeline routes. Technique and technology of petrochemical and oil and gas production), Proceedings of 8th international scientific and technical conference, 2018, pp. 30–32.

12. Chesnokova M.G., Shalay V.V., Kriga A.S., The relevance of studying soil biocorrosive activity in establishing an integrated action criterion combined effect of corrosion factors, Procedia Engineering, 2016, V. 152, pp. 420–422.

The process of oil production is accompanied by the impact on all components of natural environments: atmospheric air, soil and vegetation cover, surface waters, including bottom sediments. In the conditions of the Middle Ob region, with its high degree of swampiness and lakes, it is the bog-lacustrine ecosystems that are the most vulnerable in the course of human economic activity. This also applies to the territory of the Lyantorskoye oil and gas condensate field, developed since 1978, in the landscape structure of which lake-bog complexes occupy almost 80% of the territory. At long-term developed fields, primarily those whose exploitation began in the Soviet period, background observations of the state of natural environments, including surface water and bottom sediments, were not carried out. This gap was filled only in the post-Soviet period, and at the beginning of the 21st century, hydrochemical studies became regular with the determination of a large number of pollutants. The Lyantorskoye field, like other long-term developed fields, is also covered by annual hydrochemical studies with a large number of determined components in 10 watercourses. The results of these studies are presented in the article. As a result of the analysis of the current state of the surface waters of the Lyantorskoye field, it was established that the presence of phenols, biogenic substances, heavy metals and other chemical substances in the surface waters, the content of which exceeds the established maximum permissible concentrations. This is typical not only for the rivers of this field, but also for other watercourses in the territory of the Khanty-Mansiysk Autonomous District - Yugra, where hydrocarbon production is not carried out. The noted is associated with the natural features of the area and the processes taking place in the bowels of the earth. Analysis of the research results indicates that the long-term operation of the Lyantorskoye field did not have a visible effect on the hydrochemical state of surface waters and bottom sediments of the field's streams. The increased content of some pollutants is caused not only by technogenic factors, but by the natural features of the taiga zone of Western Siberia.

References

1.  Shubaev L.P., Surgut Polesye of West Siberian Lowland (In Russ.), Izvestiya VGO SSSR = Proceedings of the Russian Geographical Society, 1956, T. 88, no. 2, pp. 167–169.

2. Liss O.L., Abramova L.I., Avetov N.A. et al., Bolotnye sistemy Zapadnoy Sibiri i ikh prirodookhrannoe znachenie (Marsh systems of Western Siberia and their conservation value): edited by Kuvaev V.B., Tula: Grif i Co Publ., 2001, 584 p.

3. Resolution of the Government of the Khanty-Mansi Autonomous Okrug-Yugra no. 485-P of 23.12.11. “O sisteme nablyudeniya za sostoyaniem okruzhayushchey sredy v granitsakh litsenzionnykh uchastkov na pravo pol'zovaniya nedrami s tsel'yu dobychi nefti i gaza na territorii Khanty-Mansiyskogo avtonomnogo okruga-Yugry” (On the system for monitoring the state of the environment within the boundaries of licensed areas for the right to use subsoil for the purpose of oil and gas production in the Khanty-Mansiysk Autonomous Okrug-Yugra).

4. Moskovchenko D.V., Ekogeokhimiya neftegazodobyvayushchikh rayonov Zapadnoy Sibiri (Ecogeochemistry of oil and gas regions of Western Siberia), Novosibirsk: Geo Publ., 2013, 259 p.

Modeling the economy of competing refineries and the industry as a whole causes a number of difficulties due to limited information about processing facilities. The development of Russian oil refining on the basis of large investments requires weighted assessments taking into account all available information. The modeling tools and the application of its results vary depending on the analysis of the individual refinery or their group. There is a need for tools to generate a set of evaluation parameters of Russian refineries that will provide comparable simulation results for each facility, regardless of the availability of information.

The purpose of the paper is to develop and test tools that allow to obtain the parameters of the refinery and form a Russian oil refining model based on them. In the absence of key data on the material balances of technological installations, flows of intermediates and their properties, prices for the sale of petroleum products and the purchase of oil, procedures were proposed to obtain estimates of the missing data. A number of assumptions were introduced to assess the material balances of technological processes of oil refineries. As a result, a set of estimates of the material balances of the refinery's technological processes has been obtained, which correspond to real ranges of values, satisfy the actual production of products and provide a condition for the economic optimality of the actual volume of crude oil processing. Having formed the price parameters and evaluated the material balances of the installations, a target economic function was compiled, the maximization of which is achieved by optimizing the volume of processed oil raw materials. Based on the model, a scenario forecast was built with detailing of indicators to the level of a separate refinery with the ability to analyze the dynamics of the corporate structure. The obtained results can be used as a basis for long-term management decisions regarding the development strategy of refineries or the preparation of marketing and investment policies of plants.

References

1. Ketabchi E., Mechleri E., Gu S., Arellano-Garcia H., Modelling andoptimisation approach of an integrated oil refinery and a petrochemical plant, Computer Aided Chemical Engineering, 2018, V. 44, pp. 1081-1086, http://doi:10.1016/B978-0-444-64241-7.50175-0

2. Sales L., Luna F., Prata B., An integrated optimization and simulation model for refinery planning including external loads and product evaluation, Braz. J. Chem., 2018, V. 35, no. 1, pp. 199-215, http://doi:10.1590/0104-6632.20180351s20160124

3. Oliveira F., Nunes P., Blajberg R., Hamacher S., A framework for crude oil scheduling in an integrated terminal-refinery system under supply uncertainty, European Journal of Operational Research, 2016, V. 252(2), pp. 635–645, http://doi:10.1016/j.ejor.2016.01.034

4. Ulanov V., Business development in emerging economies on the basis of limits and conditions of national strategies, Global Journal of Emerging Market Economies, 2019, V. 11, no. 1–2, pp. 37–47, http://doi:10.1177/0974910119871376

5. Klochko O., Grigorova A., Models of oil exporting countries’ inclusion into oil refining global value chains (In Russ.), Mirovaya ekonomika i mezhdunarodnye otnosheniya, 2020, no. 1, pp. 99–109, http://doi:10.20542/0131-2227-2020-64-1-99-109

6. Yakovlev A., Vyglovsky O., Demidova O., Bashlyk A., Incentives for repeated contracts in public sector: Empirical study of gasoline procurement in Russia, International Journal of Procurement Management, 2016, V. 9, no. 3, pp. 99–109, http://doi:10.1504/IJPM.2016.076305