The Bazhenov formation is the main source formation in Western Siberia and contains oil-saturated reservoirs. The Bazhenov formation is promising for oil production, but at the same time it is extremely complex. The article proposes a multi-level lithological typization of sediments, developed o based on the study of more than 100 wells with the core of the Bazhenov formation within the Khanty-Mansiysk Autonomous District. Lithotypization contains 4 levels of detail. The first level includes two classes of rocks: carbonate-clay-carbon-siliceous (oil source rocks) and siliceous-carbonate (potential reservoirs). The rocks of the first class are oil source, contain liquid hydrocarbons in a sorbed state, which cannot be extracted using existing technologies. The rocks of the second class are also oil source, however, they often have reservoir properties, which is justified by a comparison of core studies with well and field studies to determine the intervals of inflow. The second level of litho typization contains seven groups of lithotypes, which are divided by the ratio of rock-forming components. Groups of lithotypes of the first class have their location in the section and differ in logging curves; it is extremely difficult to separate the groups of lithotypes of the second class according to the logging data and they can be found throughout the section. The third level of lithotypification consists of 11 lithotypes, distinguished by mineral composition, organic matter content, structural and texture features. The fundamental difference between this typification and the previous ones is the consideration of the texture features of the rocks, which allows you to immediately separate the source rocks and potential reservoirs. The fourth level of lithotypization is the mapping of the variety of rocks of the Bazhenov formation, where 33 subtypes of rocks are distinguished, which differ in mineral and biogenic inclusions, impurities, textures, and secondary transformations. Isolation of lithological subtypes of rocks with a characteristic set of faunal residues and impurities is necessary during detailed facies reconstructions. This classification allows the transition from studying rocks in transparent sections to building a three-dimensional geological model without losing a large amount of detailed lithological information. Confidently interpret the well data, compare geological sections of the suite according to core and GIS data with each other, determine the factors that control the productivity of the stratum, establish patterns of distribution of properties of potential reservoirs.

References

1. Korovina T.A., Zakonomernosti formirovaniya i rasprostraneniya kollektorov v bituminoznykh otlozheniyakh bazhenovskoy svity dlya otsenki perspektiv neftegazonosnosti zapadnogo sklona Surgutskogo svoda (Patterns of formation and distribution of reservoirs in the bituminous sediments of the Bazhenov formation to assess the oil and gas potential of the western slope of the Surgut arch): thesis of candidate of geological and mineralogical science, St. Petersburg, 2004.

2. 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.

3. Panchenko I.V., Razmyvy v bazhenovskikh otlozheniyakh Zapadnoy Sibiri: znachenie dlya korrelyatsiy razrezov i prognoza kollektorov (Scour in the Bazhenov sediments of Western Siberia: the value for the correlation of sections and reservoir forecast), Proceedings of 3rd EAGE/SPE scientific workshop “Nauka o slantsakh” (The science of shale), Moscow, 2019.

4. Alekseev A.D., Nemova V.D., Koloskov V.N., Gavrilov S.S., Lithological peculiarities of Lower Tutleimsky subsuite structure of Frolovsky oil-and-gas-bearing area in view of its oil potential (In Russ.), Geologiya nefti i gaza = The journal Oil and Gas Geology, 2009, no. 2, pp. 27-33.

The paper reviewed the main physicochemical characteristics of certain types of clay minerals, the differences in which predetermine the differences in the complex of measures aimed at intensifying oil production. The object of research is terrigenous rocks of the Vasyugan suite (formation U1), characterized by polymineral clay cement, which includes kaolinite, chlorite, a group of hydromica minerals. Each of the selected minerals has different crystal chemical (ability to swell) and physicochemical characteristics (size of specific surface area, cation-exchange ability). According to the results of a comparative analysis of laboratory and special studies, it was found that rocks with a high content of kaolinite are characterized by low values of both specific surface size and cation exchange capacity, and rocks with a high content of hydromica group of minerals are characterized by high values of these values, which confirms the influence of the mineral and quantitative composition of clay cement on the physicochemical characteristics of rocks. Detailed lithological-technological typification of rocks was performed considering the described issues and the results of previous studies. Three types are distinguished. Each of them is characterized by a certain qualitative and quantitative composition, physicochemical features, and a complex of geological and technological measures, which are recommended to be applied at sites (in intervals) of distribution of a certain lithological-technological type, in order to intensify production. Thus, in the zones of distribution of rocks of type I, it is most effective to carry out activities using additives of various surfactants, or carbon dioxide. In the zones of development of rocks of type II, all existing types of geological and technological measures will be effective. In zones of type III rock distribution, it is possible to use chemical methods to intensify oil production.

References

1. Sokolov V.N., Microcosm of clay rocks (In Russ.), Sorosovskiy obrazovatel'nyy zhurnal, 1996, no. 3, pp. 56–64.

2. Kravchenko I.I., Babalyan G.A., Adsorbtsiya PAV v protsesse dobychi nefti (The adsorption of surfactants in the oil production), Moscow: Nedra Publ., 1971, 159 p.

3. Kolpakov V.V., Zholudeva V.A., Saetgaleev Ya.Kh., Efficiency enhancement of geological exploration and risks reduction of deposits development based on lithological-technological modeling of clay collectors of Yu1 formation of Kogalymsky region (In Russ.), Neftepromyslovoe delo, 2017, no. 10, pp. 9–13.

4. Sarkisyan S.G., Kotel'nikov D.D., Glinistye mineraly i problemy neftegazovoy geologii (Clay minerals and problems of oil and gas geology), Moscow: Nedra Publ., 1980, 232 p.

5. Bregg V.G., On the structure and properties of clays (In Russ.), Uspekhi fizicheskikh nauk, 1939, V. 26, pp. 1–20.

6. Shmyrina (Zholudeva) V.A., Morozov V.P., Morfogeneticheskie osobennosti glinistykh mineralov produktivnykh na neft' otlozheniy Kustovogo mestorozhdeniya (plasty BS111 i YuS11) (Morphogenetic features of clay minerals of oil-producing deposits of Kustovoye oilfield (BS111 and YuS11 layers)), Collected papers “Leningradskaya shkola litologii” (Leningrad School of Lithology), Proceedings of All-Russian Lithological Conference dedicated to the 100th anniversary of the birth of L.B. Rukhin, Part 2, St. Petersburg: Publ. of SPbSU, 2012, pp. 202–204.

The Russian sector of the Caspian Sea is one of the promising regions for the search for hydrocarbon deposits. The results obtained from the processing of seismic facies, lithological, geophysical, petrophysical and other researches indicate that the main prospects are connected with the carbonate Upper Jurassic-Lower Cretaceous complex of deposits. The development predicted at the initial stage of research in this (previously considered to be Tithonian) complex of rifogenic type traps has not been confirmed. Along with this, materials are accumulating that indicate the possible presence in this region of a significant number of non-structural oil and gas traps of lithological, stratigraphic and combined types. Search and exploration of deposits of this type dictate the need for a well-developed stratification scheme. The territory of the Northern Caspian Sea is of great scientific interest from the perspective of paleogeographic events that took place at the turn of the Jurassic and Cretaceous: it is through this region that water masses and marine biota were exchanged between the Boreal and Tethyan basins. The joint analysis of stratigraphic and paleogeographic data on the Northern Caspian Sea can provide key information for the Boreal-Tethys correlation and justification of the Jurassic-Cretaceous boundary in the boreal sections. In this regard, the initial figures about the structure of the Jurassic-Cretaceous sequence of the region that were obtained by drilling are of particular interest. It is established that the carbonate complex previously attributed to the formations of the titon tier should be considered as a transitional Tithon-Berriass, and the productive I layer, represented by fractured-cavernous dolomites, should be attributed to the Berriasian. Inter-well correlation of the refined roof of Jurassic system sediments was executed using three independent methods. The one-dimensional modeling performed taking into account the VSP and drilling data, made it possible to correctly stratigraphically link the reference horizons to the borehole data and unambiguously correlate the target horizons. The seismic facies analysis showed that in the upper part of the Upper Jurassic deposits there is a zone of the release of individual phases under the roof of the Upper Jurassic deposits. The obtained geological results confirm the assumption about the possible development of stratigraphic screening traps in this region.

References

1. Smirnov M.V., Baraboshkin E.Yu., Bogdanova T.N. et al., Tithonian and Neocomian of Northern Caspian (In Russ.), Byulleten' Moskovskogo obshchestva ispytateley prirody. Otdel geologicheskiy, 2004, V. 79, no. 2, pp. 30–39.

2. Guzhikov A.Yu., Molostovskiy E.A., Stratigraphic informativeness of numerical magnetic characteristics of sedimentary rocks (methodical aspects) (In Russ.), Byulleten' Moskovskogo obshchestva ispytateley prirody. Otdel geologicheskiy, 1995, V. 70, no. 1, pp. 32–41.

3. Guzhikov A.Yu., Geological informativeness of the magnetism of the core and sludge sedimentary rocks obtained during the drilling of exploratory wells (In Russ.), Pribory i sistemy razvedochnoy geofiziki, 2013, no. 4(46), pp. 51–61.

4. Kuznetsov A.B., Semikhatov M.A., Gorokhov I.M., Strontium isotope stratigraphy: Principles and state of the art (In Russ.), Stratigrafiya. Geologicheskaya korrelyatsiya = Stratigraphy and Geological Correlation, 2018, V. 26, no. 4, pp. 3–23.

5. Wierzbowski H., Anczkiewicz R., Pawlak J. et al., Revised Middle–Upper Jurassic strontium isotope stratigraphy, Chemical Geology, 2017, V. 466, pp. 239–255.

6. Kuznetsov A.B., Izokh O.P., Dzyuba O.S., Shurygin B.N., Sr isotope composition in belemnites from the Jurassic–Cretaceous boundary section (Maurynya River, Western Siberia) (In Russ.), Doklady RAN = Doklady Earth Sciences, 2017, V. 477, no. 4, pp. 455–460.

7. Baraboshkin E.Yu., Naydin D.P., Ben'yamovskiy V.N. et al., Prolivy Severnogo polushariya v melu i paleogene (Straits of the Northern Hemisphere in the Cretaceous and Paleogene), Moscow: Publ. of MSU, 2007, 182 p.

8. Baraboshkin E.Yu., Shtun' S.Yu., Guzhikov A.Yu. et al., Sedimentologiya i stratigrafiya pogranichnogo yursko-melovogo intervala karbonatnogo rampa Severnogo Kaspiya (Sedimentology and stratigraphy of the border Jurassic-Cretaceous interval of the carbonate ramp of the Northern Caspian), Collected papers “Melovaya sistema Rossii i blizhnego zarubezh'ya: problemy stratigrafii i paleogeografii” (The Cretaceous system of Russia and neighboring countries: problems of stratigraphy and paleogeography), Proceedings of IX All-Russian meeting, 17–23 September 2018, Belgorod: Politerra Publ., 2018, pp. 54–58.

9. Baraboshkin E.Yu., Rogov M.A., Guzhikov A.Yu. et al., Kashpir section (Volga River, Russia), the proposed auxiliary section for the J/K interval in Subboreal Realm, Proceedings of XII Jurassica Conference. Field Trip Guide and Abstracts Book, Smolenice, Slovakia: Publ. of Earth Science Institute, Slovak Academy of Sciences, Bratislava, 2016, pp. 109–112.

Perm region has its long-time oil production history. Nowadays significant part (61%) of residual oil here is associated with low-productive carbonate formations. Horizontal well drilling is one of the main ways to achieve commercial success in these geological conditions. Widely spread lateral drilling has high demand on well placement service to maintain horizontal sections within the reservoir. Well placement is the process of interactive positioning of a wellbore based on real-time geological data and technological measurements. In general, horizontal drilling in Perm region is focused on three carbonate formations: Upper Devonian - Tournaisian, Upper Visean - Bashkirian and Kashirian - Werenian.

The article describes different well drilling approaches depending on each formation’s own features. At present time, lateral drilling in Perm Region is supported by geosteering service based on real-time LWD data. Paper describes LWD methods and well placement approaches which are used in Perm region. Geosteering is a proven technology that allows increasing of effective lateral length of the well despite downward geological environment: net pay decrease, high heterogeneity etc. More than 40% of annual production rate (from new wells) is based on horizontal wells landed with well placement service. Horizontal well placement brought the opportunity of profitable production for fields with complicated geology which weren’t consider earlier as a target for lateral drilling because of high failure probability.

References

1. Joshi S.D., Cost/benefits of horizontal wells, SPE-83621-MS, 2003.

2. Lebedev S.V., Sayfitdinova V.A., Kochneva S.V. et al., Geonavigatsiya v karbonatakh. Uspeshnoe primenenie tekhnologii mnogoplastovogo kartirovaniya razreza pri burenii gorizontal'nykh skvazhin (Geosteering in carbonates. Successful application of multilayer section mapping technology for horizontal wells), Proceeding of conference “Geobaykal 2018”, Irkutsk: Publ. of EAGE, 2018.

3. 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, 335 p.

The systematic work on search and introduction of the new methods and technologies is conducted on Perm Kray oilfields in order to increase the oil recovery of a productive formation. The sidetraking is one of such technologies that allow to increase the efficiency of oilfields at a late stage of development, to increase the enhanced oil recovery and to return to operating previously drilled oil wells. The development of the sidetrack construction technology in the Perm region oilfields is considered. The methods of cut out sidetrack, currently used in the well construction in the Perm region oilfields, are presents. Great attention is paid to the technology of multilateral wells construction. Drilling of MSS is also aimed at the residual localized oil reserves extraction of and allows to put into operation emergency and non-operating wells, as well as to work on wells which depleted their reserves. At the present level of drilling operations, multilateral well technology is turning into a viable alternative to traditional methods of oilfield development. The experience of the design and testing of multilateral wells construction technology and horizontal sidetrack technology in the oilfields of Perm region is considered. The development and widespread introduction of domestic equipment for multilateral and multi-hole wells construction, all levels of organization of the joint of the additional borehole from TAML-1 to TAML-5, will provide the further development of this technology and the transition from quantitative to new qualitative development of the oil and gas industry.

References

1. Chernyshov S.E., Turbakov M.S., Krysin N.I., The main directions of improving the efficiency of the construction of sidetracks (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2011, no. 8, pp. 98–100.

2. Gilyazov R.M., Sovershenstvovanie tekhniki i tekhnologii bureniya bokovykh stvolov (Improving the technology and technology of drilling sidetracks): thesis of doctor of technical science, Ufa, 1999.

3. Okromelidze G.V., Fefelov Yu.V., Suntsov S.V., Kuchevasov S.I., The experieence of design and construction of multihole wells (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2011, no. 10, pp. 54–55.

4. Lyadova N.A., Il'yasov S.E., Okromelidze G.V. et al., The experience of design and construction of a multihole wells (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2014, no. 3, pp. 58–60.

5. Garshina O.V., Predein A.A., Klykov P.I. et al., Geomechanical modeling as an integral part of a complex approach to wells construction in complicated geological conditions (In Russ.), Neftepromyslovoe delo, 2017, no. 5, pp. 28–33.

The article describes the successful experience of geosteering while drilling wells with a long horizontal completion in the Upper Jurassic deposits. The article deals with the issues of geology of the object, the structure of the section of the target sediments, also example of reservoirs discrimination is given. Reservoirs in the section of the Upper Jurassic sediments are interlayers 0.5–3.0 m thick, which can be clearly distinguished according to geophysical studies of wells and cores. A well test field experiment conducted to substantiate the position of the reservoirs in the section is described. The choice of the target interval for drilling long horizontal boreholes in order to maintain the stability of the wellbore and obtain maximum oil inflows is validated. The goal was to support the drilling of horizontal shafts in the target interval of Upper Jurassic sediments with a thickness of 3-5 m. In the conditions of the impossibility of attracting high-tech logging complex for horizontal shafts, a method of geosteering in Upper Jurassic deposits using GR and rock cuttings during the drilling process has been developed. The high degree of characterization of the Upper Jurassic deposits by the data of core studies made it possible to identify indicator elements, the changes of which are most contrasting in different interlayers. Based on the analysis of drilling results, a series of conclusions was made. The proposed technique was tested in the process of drilling 9500 m of horizontal shafts and its high information content and reliability was confirmed. This technology is not expensive and can be implemented on any field after equipping the station for geotechnical well testing with portable devices for determining the elemental composition of rocks. To replicate this technology to other fields, it is necessary to study the reference sections of target sediments from the point of view of layer-by-layer changes in the elemental composition of rocks.

References

1. 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.        

2. Slavkin V.S., Alekseev A.D., Koloskov V.N., Some aspects of a geological structure and prospects of oil-bearing capacity of Bazhenovskaya suite in the West of latitudinal Priobye (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2007, no. 8, pp. 100–104.

3. Nemova V.D., Gavrilov S.S., Issledovaniya kerna otlozheniy bazhenovskogo gorizonta, kak osnova dlya interpretatsii dannykh seysmorazvedki (Research core of deposits of Bazhenov horizon, as the basis for the interpretation of seismic data), Collected papers “Petrofizika slozhnykh kollektorov: problemy i perspektivy 2014” (Petrophysics of complex reservoirs: problems and prospects for 2014), Moscow: Publ. of EAGE Geomodel', 2014, pp. 212–230, ISBN 978-94-6282-030-2.

4. Nemova V.D., Panchenko I.V., Localization of inflow intervals and storage volume of the Bazhenov formation, Sredne-Nazym oil field (In Russ.), Neftegazovaya geologiya. Teoriya i praktika, 2017, V. 12, no. 1, URL: http://www.ngtp.ru/ rub/4/11_2017.pdf

5. Nemova V.D., Panchenko I.V., The productivity factors of Bazhenov formation in Frolov megadepression (Western Siberia) (In Russ.), Neftegazovaya geologiya. Teoriya i praktika, 2017, V. 12, no. 4, URL: http://www.ngtp.ru/rub/ 4/46_2017.pdf

Sidetracking is one of the most effective technologies that allows increasing oil production while expanding reserves and increasing oil recovery fr om reservoirs, returning oil wells to operation. In the region wh ere LUKOIL-Western Siberia LLC operates, these fields include Vatieganskoye, which has been developed since 1985. The main problem with sidetracking in this field is the section of unstable clay-argillite rocks (Pokachev-Savoy rock unit), drilling-in at large zenith angles, as well as transit and target productive formations with abnormally low formation pressures. At present, a set of measures has been formed that allow preventing the occurrence of accidents and complications horizontal sidetracking in incompatible conditions, reducing unproductive time. The activities include: optimization of the candidate well selection process for the sidetracking; pre-design and research work to improve the design, formulation of drilling mud, wiring technology and completion of sidetracks; conducting pilot tests; construction and updating of geomechanical models.

The positive results of introducing an integrated approach for well reconstruction using sidetracking method in incompatible geological and technological conditions made it possible to construct sidetracks with multilateral horizontal completion, which ensured an increase in drainage area and well productivity. The current experience and technical and technological solutions were widely used in sidetracking operations and in production drilling in difficult conditions.

References

1. Fazylov D.A., Mazur G.V., Rezul'taty vnedreniya metodiki po kriteriyam slozhnosti profiley bokovykh stvolov s gorizontal'nym okonchaniem (The results of the implementation of the methodology according to the complexity criteria of sidetrack profiles with horizontal ending), Proceedings of XVIII Conference of young scientists and specialists of the Branch of LUKOIL-Engineering LLC, Tyumen', 2018, pp. 565–573.

2. Malyutin D.V., Bakirov D.L., Babushkin E.V., Svyatukhov D.S., Geomechanical modeling to solve the problem of wells construction in LLC "LUKOIL-Western Siberia" (on the example of Vategansky deposit) (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2016, no. 11, pp. 23–26.

3. Malyutin D.V., Bakirov D.L., Babushkin E.V., Svyatukhov D.S., The results of 1D geomechanical modeling application by LLC "LUKOIL-West Siberia" when drilling wells (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2017, no. 9, pp. 52–58.

4. Tikhonov E.V., Sokovnin S.A., Dolmatov A.P. et al., Drilling low pressure reservoirs in Western Siberia: BARADRIL-N®/Mineral oil, oil in water emulsion (In Russ.), Burenie i neft', 2013, no. 10, pp. 50-52.

5. Sokovnin S.A., Tikhonov E.V, Kharitonov A.B. et al., Best practices – Direct emulsion-based drilling solution as a new approach to drilling in mature fields with low reservoir pressure (In Russ.), SPE 176519-MS, 2015.

6. Bakirov D.L., Babushkin E.V., Fattakhov M.M., Malyutin D.V., Improving the efficiency of multilateral wells construction by the use of oil-based drilling fluids (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 8, pp. 28–30.

To ensure the maintenance and growth of cost-effective oil production in the fields of Western Siberia, in the face of an objective deterioration in the structure of current reserves, it is necessary to use modern, innovative approaches and development technologies. One of such technologies for LUKOIL-Western Siberia LLC was the development of hydrocarbon deposits in multilateral wells. Currently, the technical aspects of the construction of multilateral wells are not difficult. The method is applied on an industrial scale. More than 200 wells have been drilled in 24 fields. With such a significant number of multilateral wells constructed, it is worth noting that the practical experience of their application in the framework of regular development systems for individual independent oil deposits of LUKOIL-Western Siberia LLC is not so great. The reasons for this situation are obvious; the current drilling is largely confined to the oil deposits of the developed fields. Accordingly, there is the use of multilateral wells as part of already formed development systems. Maintaining reservoir pressure in most cases is carried out by directional injection wells. Injection of a working agent into injection wells with horizontal completion often has the status of pilot works. Placement of horizontal and multilateral wells is carried out in accordance with classical development systems designed for vertical wells or single-hole horizontal wells. An example of the design and formation of development systems for multilateral wells is the Pyakyakhinskoye field, the main oil facilities of which are fully drilled by multilateral wells. Formation pressure is maintained by injection horizontal wells. New fields of LUKOIL-Western Siberia LLC, such as: Imilorskoye, Zapadno-Pokamasovskoye, Vostochno-Ikilorskoye, are commissioned using multilateral wells as part of independent development systems. he large-scale use of multilateral wells requires the introduction of development systems adapted to the filtration conditions of formation fluids. The article presents the experience of designing and the actual implementation of development systems using multilateral wells in the fields of LUKOIL-Western Siberia LLC, conclusions and recommendations are made.

References

1. Bakirov D.L., Fattakhov M.M., Mnogozaboynye skvazhiny: prakticheskiy opyt Zapadnoy Sibiri (Multilateral wells: practical experience of Western Siberia), Tyumen': Tyumenskiy dom pechati Publ., 2015, 232 p.

2. Patent no. RU2016117788A, Oil deposit development method, Inventors: Zaytsev A.V., Mavletdinov M.G., Solyanov S.A.

Since 2008, PermNIPIneft Branch of LUKOIL-Engineering LLC in Perm has been performed a complex of works on scientific-engineering support of hydraulic fracturing at Perm region fields and since 2017 it has been the same at the fields of the Komi Republic and the Nenets autonomous district. Hydraulic fracturing technology is implemented at all oil and gas bearing complexes of the regions. Significant differentiation of geological and physical characteristics of productive formations causes an individual approach at the performance of hydraulic fracturing for each production zone. The main objectives of improving the hydraulic fracturing technological efficiency are the following: increasing of the fracture conductivity, increasing of conformance along the horizontal and in a vertical sense, reducing uncontrolled leakage of breakdown agent, excluding the water-cut growth, reducing the fracture height in the conditions of nearby gas-and water-saturated intervals. The article presents the main problems of hydraulic fracturing for each of the considered oil and gas bearing complexes, describes the main technological solutions. Continuous improvement of hydraulic fracturing method is carried out for maintaining a stable technological efficiency in the conditions of gradual deterioration of geological and physical conditions of wells-candidates. The main areas of work are identified and technology modifications are successfully selected for solving the existing problems of development and the problems of effective hydraulic fracturing implementation.

References

1. Voevodkin V.L., Aleroev A.A., Baldina T.R. et al., Razvitie tekhnologiy gidravlicheskogo razryva plasta na mestorozhdeniyakh Permskogo kraya (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 11, pp. 108–113.

2. Kondrat'ev S.A., Zhukovskiy A.A., Kochneva T.S., Malysheva V.L., Opyt provedeniya proppantnogo gidrorazryva plasta v karbonatnykh kollektorakh mestorozhdeniy Permskogo kraya (Experience of proppant hydraulic fracturing in the carbonate reservoirs of the Perm Region), Moscow: Publ. of VNIIOENG, 2016, 68 p.

3. Aleroev A.A., Kondrat'ev S.A., Sharafeev R.R. et al., Performance of proppant hydraulic fracturing in low-permeability oil reservoirs of the Nenets autonomous district (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 9, pp. 108–111.

4. Votinov A.S., Drozdov S.A., Malysheva V.L., Mordvinov V.A., Recovery and increase of the productivity of wells of Kashirskiy and Podolskiy reservoirs of the certain Perm region oil field (In Russ.), Vestnik Permskogo natsional'nogo issledovatel'skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2018, V. 18, no. 2, pp. 140–148, DOI: 10.15593/2224-9923/2018.4.4.

The article considers the possibility of increasing the efficiency of oil recovery in one of the fields in Iraq, which has been actively developed for several years using the waterflooding process. The object of development is the Mishrif reservoir with a fracture reservoir. At the same time, a decrease in reservoir pressure has been noted recently due to insufficient compensation of reservoir energy by pumped water. Based on the complex data analysis from well logging, aerospace geology, well testing, well development and operation indicators, conclusions are drawn about the emerging negative trends in field development associated with changes in fracture configurations, which in turn is due to a decrease in reservoir pressure below their closure pressure. To take into account the distribution of the volume and permeability of the cracks, the previously used methodology for constructing a model of the volumetric network of cracks tested at the objects of the Perm region and the Republic of Komi, adapted in the course of research to the specific conditions of the field under consideration. An analysis of the results showed the possibility of applying the methodologies used at carbonate sites in Russia for the conditions of Iraq. Based on the constructed model of a network of fractures, analysis of changes in the permeability of the formation during the development and analysis of other technological indicators, specific technological recommendations have been issued for restoring the reservoir pressure and for choosing the operating mode of the wells, as well as for placing additional production and injection wells. A feasibility study of the proposed recommendations has been made. Taking into account the revealed dynamic dependences of permeability on pressure, the location of fracture zones, can significantly reduce the well stock and capital investment at the research object.

References

1. Makhavi M.M., Geologicheskoe obosnovanie kompleksnogo osvoeniya uglevodorodnykh resursov yuga Iraka (Geological justification for the integrated development of hydrocarbon resources in south of Iraq): thesis of candidate of geological and mineralogical science, Ufa, 2010, 24 p.

2. Sablin R.A., Ramazanov A.M., Some specific features of resources recovery in carbonate heterogeneous collectors on the example of Mishrif object of the deposits located in the South of Iraq (In Russ.), Neftepromyslovoe delo, 2018, no. 5, pp. 5–14.

3. Holden A., Lehmann C., Ryder K. et al., Integration of production logs helps to understand heterogeneity of Mishrif reservoir in Rumaila, SPWLA-2014-GGG, Proceedings of SPWLA 55th Annual Logging Symposium, 18–22 May, Abu Dhabi, United Arab Emirates.

4. Kotyakhov F.I., Fizika neftyanykh i gazovykh kollektorov (Physics of oil and gas reservoirs), Moscow: Nedra Publ., 1977, 363 p.

For the successful implementation of large capital projects LUKOIL Company has implemented a phase approach, formalized in an integrated project management system and ensuring on-time identification of risks and economical assessment of different asset development options. One of the elements of an integrated project management system is an integrated model allowing production profile calculation, taking into account the interaction of wells through the reservoir and the surface infrastructure. Using of the integrated model also allow to estimate the probabilistic distribution of economic indicators of the project through multivariate calculations, to identify risks and contradictions of design decisions in various functional areas and discover opportunities to optimize projects that do not achieve targeted economic efficiency. In this article, using the example of the D33 offshore field of the Baltic Sea, the main tasks of the early stages of the project implementation are considered and the advantages of using integrated models for solving them are highlighted. The main approaches used in the calculations were: probabilistic modeling to assess the uncertainties of technological indicators and the associated risks; modeling of the downhole equipment control in intelligent wells providing improvement of oil recovery; multivariate integrated modeling to optimize capital and operating costs. By optimizing the position of production wells, optimal selection of ESP and downhole equipment and automatic control of well operation modes in IAM at phase 2 of the project, it was possible to keep the oil production levels planned for phase 1 while reducing the number of producing wells and refusing to use a boosting multiphase pump. Implementation of the proposed solutions allows reducing the cost of the project and increasing the project IRR by 0.6 %. According to the results of the described works, IAM based approach has been recommended for use in the initial phases on all LUKOIL major capital projects.

The article highlights the activities of LUKOIL PJSC in the area of research, adaptation and testing of new technologies as part of the implementation of the Pilot Operation Program in the Company. Statistical data on the pilot operation performance and on the transition of the technologies to the commercial operation stage is provided. The history of enhancing the hydraulic fracturing technologies, construction of multibranch wells (multilateral and multihole ones), drilling of slim wells is highlighted as examples of development of the innovative directions on the “from simple to complicated” basis. As part of development of the hydraulic fracturing area, information is provided regarding the evolution of applicable hydraulic fracturing technologies from formation injection operations (up to 10 t of propping agent) to large-scale hydraulic fracturing (100 t and more) and, further, to multistage hydraulic fracturing technologies for horizontal wells. The data on the efficiency of multistage hydraulic fracturing at LUKOIL PJSC fields is provided. The development of multilateral well construction technologies in the Company is represented from the drilling of first multilateral wells with double completion and further to the construction of multihole wells with TAML-5 complexity degree at the offshore fields. Drilling of slim wells obtained its development and distribution across LUKOIL PJSC primarily due to its economic viability for the conditions of the mature fields operating at the advanced development stages. Starting from year 2010, the slim well drilling technologies have evolved from pilot operations to the level of engineering solutions for field development project design documentation. Besides, in 2017, a first multilateral slim well was successfully drilled at the Osinsky field, and a sidetracking technology for slim wells was developed.

References

1. Mulyak V.V., Chertenkov M.V., Shamsuarov A.A. et al., Increasing efficiency of hard-to-recover reserves involving in the development with use of multi-zone hydraulic fracturings in horizontal wells (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2011, no. 11, pp. 48–51.

2. Voevodkin V.L., Aleroev A.A., Baldina T.R. et al., The evolution of the hydraulic fracturing technology on the fields of Perm region (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 11, pp. 108–113.

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.

Development of offshore oil fields is one of the perspective areas for oil and gas companies. Performing offshore operations require significant means for the implementation of well construction projects. High cost of capital investment is one of the most important problems in the process of involving subsea deposits in the production of mineral resources.

The optimal methods of offshore drilling units considered in the article are based on the searching the compliance of the technical characteristics of drilling platforms with the geographical, metocean and climatic drilling conditions which determines the economic efficiency of offshore operations.

The authors have analyzed various options for drilling operations, including jack-ups, semi-submersible drilling rigs, as well as tender assist drilling units. Advantages and disadvantages of using various types of drilling units for wells construction at D33 field in the Baltic Sea have been addressed, the special aspects of tender assist drilling technologies used by foreign companies have been considered.

Actual approaches to the development of hydrocarbon resources on the shelf with use of modern floating drilling units make it possible not only to analyze the technical and economic efficiency of work, but also to estimate the possible drilling risks using different types of drilling platforms.

References

1. Bogoyavlenskiy V.I., Prospects and problems of the Arctic shelf oil and gas fields development (In Russ.), Burenie i neft', 2012, no. 11, pp. 5–9.

2. Ampilov Yu., Fields of the Russian shelf (In Russ.), Neftegas, 2014, no. 10, pp. 20–27.

3. ND 2-020201-012. Pravila klassifikatsii, postroyki i oborudovaniya plavuchikh burovykh ustanovok i morskikh statsionarnykh platform (Rules for the classification, construction and equipment of floating drilling rigs and offshore fixed platforms).

4. Smidth F., Contractors M., Georges C., Deepwater skid-over solution for marginal field development at the Froy field, SPE 35041-MS, 1996, https://doi.org/10.2118/35041-MS .

5. MODU Dayrates, URL: https://www.infield.com/rigs/report-rig-day-rates

Due to the increasing cost of offshore oil and gas fields development there is a world tendency of using unmanned technologies. In order to reduce the cost of offshore structures construction and operation technologies involving using both subsea production systems and remote operated fixed platforms have been successfully applied. Choosing the most optimal development option in terms of technological and economic perspective, application of above-water offshore structures is much more preferable given that at present the costs for subsea development options and conventional offshore structures are comparable. Further reduction of offshore development costs becomes possible with unmanned offshore structures. The article covers global experience of using remote operated unmanned platforms in different regions of the world, provides classification of such structures which differ in terms of their key parameters such as: presence of a helideck, dynamic equipment, coiled tubing workover unit, firewater system, well-logging unit. The authors note the lack of experience in the construction and operation of unmanned offshore structures in Russia, as well as the insufficient existing regulatory documents governing design aspects. The article highlights the experience of developing the first national GOST R standard on the basis of the modified international ISO standard, which introduces for the first time a classification of unmanned offshore structures in terms of the personnel safety category and the category of consequences degree for potential risks arising from the operation of offshore structures.

References

1. URL: https://www.offshore-technology.com/features/featurecould-unmanned-platforms-provide-the-boost-the-n...

2. Unmanned wellhead platforms – UWHP: Summary report, Rambøll Oil & Gas, 2016, URL: https://www.npd.no/globalassets/1-npd/publikasjoner/rapporter-en/unmanned-wellhead.pdf.

One of the most important and high priority issues for the Russian oil and gas industry is the choice of options for the development of oil fields, which ensured compliance with a number of conflicting requirements: rational use and protection of mineral resources; the most complete extraction of hydrocarbon reserves; the need to maximize the budgetary efficiency of the project; ensuring the commercial attractiveness of the field development for the license holder.

As the analysis has shown, the approach proposed in the "Guidelines for the preparation of technical projects for the development of hydrocarbon deposits" to the choice of the development option contradicts the commercial interests of the hydrocarbon deposits and does not allow to maximize the economic efficiency of oil field development. This approach is based on the method of additive coagulation of the vector criterion, which includes normalized coefficients of oil, gas (free, gas cap) and condensate extraction for a cost-effective development period, normalized NPV of the license holder, normalized accumulated discounted income of the government. When determining the integral indicator of all the criteria gives the same weight.

An approach to the selection of oilfield development options based on the criteria of the maximum public net present value of the project is proposed. As a tool to stimulate the license holder to choose this option, a correction factor for reducing the rate of oil production tax is used. When the license holder selects the optimal option from the point of view of public efficiency, the adjusted rate should ensure that the license holder receives the same NPV as in the optimal variant for him. The application of this approach allows to increase the oil recovery rate and budget efficiency of the project.

References

1. Metodicheskie rekomendatsii po otsenke effektivnosti investitsionnykh proektov (Methodical recommendations according to efficiency of investment projects), Moscow: Publ. of Ministry of Economics RF, Ministerstvo finansov RF, 2008, 221 p.

2. Zubareva V.D., Sarkisov A.S., Andreev A.F., Tekhniko-ekonomicheskiy analiz neftegazovykh proektov: effektivnost' i riski (Technical and economic analysis of oil and gas projects: efficiency and risks), Moscow: Publ. of Gubkin University, 2018, 280 p.

3. Sarkisov A.S., Tekhnologiya strategicheskogo upravleniya (Strategic management technology), Moscow: Pechatnyy Dvor Publ., 2001, 312 p.

4. Duvigneau J.C., Prasad R.N., Guidelines for calculating financial and economic rates of return WBG for DFC projects, 1984, 171 p., URL: http://documents.worldbank.org/curated/en/567991468782148724/Guidelines-for-calculating-financial-an...

5. Zheltov Yu.P., Razrabotka neftyanykh mestorozhdeniy (The oil fields development), Moscow: Nedra Publ., 1986, 332 p.

The article discusses the sedimentation conditions of terrigenous sediments of the Tyumen suite in the west of the Ob region. It is shown that the ЮС2 reservoir rocks layer was formed in the setting of a wave delta, which occupied the coastal part of the extensive coastal plain in the Bathonian. The geological section of sedimentary rocks is represented by two typical elements of the delta: 1) a front that includes mouth bars processed by waves into a beach and bar complex with distributary delta channels embedded in it, and 2) a delta plain with distributary channels and crevasse splay sands.

The main reservoir is represented by the bar facies of the proximal and distal zones with the cyclical sequences and a regressive particle size profiles. The most high-quality reservoir rocks are concentrated in the proximal zone with increased sandiness and coarser granulometric composition. Sandstones form well-connected continuous bodies with different-scale layering of wave ripples, along the direction of which the flow profiles of production wells are oriented. In the distal zone of the bar deposits, the grain size, sorting and thickness of the sandy layers decrease, and the length and thickness of the layers of clayey siltstones increase, which impairs the reservoir properties and violates the cohesion of sandy bodies.

The highest injectivity of injection wells is characteristic of sandstones of the proximal zone of mouth bars and sandy deposits of the flow facies of the distributary delta channels, which have a high permeability. In low-permeable and low-pore reservoirs of distal zone of the mouth bars, the average injectivity of wells decreases more than twice. Macrofacial heterogeneity, which determines the filtration structure of the reservoir and its hydrodynamics, should be taken into account when designing the system for the location of injection and production wells, estimating residual hydrocarbon reserves and choosing geological and technological measures for their extraction.

References

1. Rykus M.V., The influence of secondary transformations on terrigenous reservoirs quality (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2018, no. 12, pp. 40–45.

2. Rykus M.V., Rykus N.G., Sedimentologiya terrigennykh rezervuarov uglevodorodov (Sedimentology of terrigenous hydrocarbons reservoirs), Ufa: Mir pechati Publ., 2014, 324 p.

3. Kontorovich A.E., Kontorovich V.A., Ryzhkova S.V. et al., Jurassic paleogeography of the West Siberian sedimentary basin (In Russ.), Geologiya I geofizika = Russian Geology and Geophysics, 2013, V. 54, no. 8, pp. 972–1012.

4. Zakharov V.A., Shurygin B.N., Levchuk M.A. et al., Eustatic signals in the Jurassic and lower cretaceous (neocomian) deposits of the West-Siberian sedimentary basin (In Russ.), Geologiya I geofizika = Russian Geology and Geophysics, 1998, V. 39, no. 11, pp. 1492–1504.

5. Rykus M.V., Lithofacies peculiarities of oil and gas-containing complexes of the Pursk region of Western Siberia (In Russ.), Neftegazovoe delo, 2019, V. 17, no. 2, pp. 14–26.

6. Chzhan Ts., Rykus M.V., About the influence of geological heterogeneity of mouth bar on the hydrodynamics of the reservoir rock of Red Forest field (China) (In Russ.), Neftegazovoe delo, 2015, no. 1, pp. 33–46.

7. Belozerov V.B., Ivanov I.A., Rezyapov G.I., Upper Jurassic deltas of West Siberia (In Russ.), Geologiya I geofizika = Russian Geology and Geophysics, 2001, V. 42, no. 11–12, pp. 1888–1896.

The article is devoted to the problems of determining and evaluating the filtration and capacitive properties of complex reservoir rocks using the results of core microtomography. Various processes were simulated directly for the three-dimensional pore space images of the samples (pore-scale modeling) to evaluate their effective properties and to obtain a more detailed understanding of the processes under study – one- and two-phase flow in porous media. The results of mathematical processing and interpretation of core computed microtomography data (μCT) allowed us to obtain relative permeabilities which can be used for three-dimensional reservoir simulation models. In comparison with experimental studies, the methods of computer microtomography together with pore-scale modeling make it possible to estimate filtration-capacitive properties with significantly lower costs and to conduct calculations for core samples, for which it is impossible to conduct experiments, as well as to rescale the results for the use in reservoir simulation models. Taking into account in a more complete way the microscale factors using the techniques of microtomography expands opportunities of reservoir simulation models for complex reservoirs, which have hard-to-recover reserves, and, as a consequence, allows more reasonable and less costly ways to solve the management problems of oil and gas field development.

References

1. Shpurov I.V., Pisarnitskiy A.D., Purtova I.P., Varichenko A.I., Trudnoizvlekaemye zapasy nefti Rossiyskoy Federatsii. Struktura, sostoyanie, perspektivy osvoeniya (Hard to recover oil reserves of the Russian Federation. Structure, status and prospects of development), Tyumen': Publ. of FGUP ZapSibNIIGG, 2012, 256 p.

2. Blunt M.J., Flow in porous media - pore-network models and multiphase flow, Current Opinion in Colloid & Interface Science, 2001, V. 6, pp. 197–207.

3. Xiong Q., Baychev T.G., Jivkov A.P., Review of pore network modelling of porous media: Experimental characterisations, network constructions and applications to reactive transport, Journal of Contaminant Hydrology, 2016, V. 192, pp. 101–117.

4. Markov P.V., Rodionov S.P., Application of porous media microstructure models when calculating filtration characteristics for hydrodynamic models (In Russ.), Neftepromyslovoe delo. – 2015. – № 11. – S. 64–75.

5. Shabarov A.B., Shatalov A.V., Markov P.V., Shatalova N.V., Relative permeability calculation methods in multiphase filtration problems (In Russ.), Vestnik Tyumenskogo gosudarstvennogo universiteta. Fiziko-matematicheskoe modelirovanie. Neft', gaz, energetika, 2018, V. 4, no. 1, pp. 79–101.

6. Ryazanov A.V., Pore-scale network modelling of residual oil saturation in mixed-wet systems, Edinburgh: Heriot-Watt University, Institute of Petroleum Engineering, 2012.

7. Valvatne P.H., Predictive pore-scale modelling of multiphase flow, London: Imperial College, 2003, 146 р.

8. Øren P.E., Bakke S., Arntzen O.J., Extending predictive capabilities to network models, SPE 52052-PA, 1998.

9. Zeyun Jiang, Kejian Wu et al., Efficient extraction of networks from three-dimensional porous media, Water Resources Research, 2007, V. 43, no. 12, рр. 1–17, DOI: 10.1029/2006WR005780.

10. Markov P.V, Rodionov S.P., Method of stochastic generation of pore network models from their parameter distribution (In Russ.), Vestnik kibernetiki, 2016, no. 3 (23), pp. 18–25.

11. Markov P.V., The relative permeability regions assignment on the basis of pore network models parameters distributions, Proceedings of Saint Petersburg 2016 International Conference & Exhibition, 11–14 April 2016. – St. Petersburg, 2016, рр. 31–35.

12. Markov P.V., Rodionov S.P., Rock typing on the basis of pore-scale models and complex well log interpretation parameters, Proceedings of International Conference & Exhibition "Tyumen 2017", EAGE, 11–14 April 2017, Tyumen, 2017, 14 р.

This article describes the well design approach for the offshore field White Tiger. As this field has a multi-reservoir structure and there is a number of infrastructure limitations related to the maximum number of well slots on a platform, the directional drilling technology has acquired a big spread. Currently, the main field parts have been developed and the field margins are being drilled. This leads to a more complicated well design and extending wells reach. In addition, the well trajectory is chosen so that the well meets the objectives of both additionally appraising the ‘risky reserves’ and penetrating the ‘proven reserves’ of a multilayered reservoir structure. The main well design maturation steps are geological justification, choosing the optimal well trajectory and casing scheme with regards to geological targets. The real time operation and geological monitoring are also considered. From the well construction point of view, the new technologies have been described that were successfully applied and contributed to skills broadening in ERD well design and drilling. The focus has been put as well on drilling fluids technology, selecting appropriate drilling rig and drill string. Should there be more complex wells planned with further outstep, the acquired skills will help in delivering these wells.

References

1. Lubnin A.A., Afanasiev I.S., Yudin E.V., System approach to planning the development of multilayer offshore field (In Russ.), SPE 176690-MS, 2015, https://doi.org/10.2118/176690-MS.

2. Lubnin A.A., Yudin E.V., Sansiev G.B., Methods to improve the efficiency of development of a multi-layer offshore gas condensate field: Thien Ung case study (In Russ.). SPE 187865-MS, 2017, https://doi.org/10.2118/187865-MS.

3. Nguyen Du Hung, Hung Van Le, Hydrocarbon geology of Cuu Long Basin – offshore Vietnam, Proceedings of AAPG International Conference, Barcelona, Spain, September 21-24, 2003.

4. Negrao A., Technology focus: Multilateral/Extended reach, SPE 0514-0130-JPT, 2014, https://doi.org/10.2118/0514-0130-JPT.

5. Netichuk I., Suvorov A., Galimov A., Special features of casing running and cementing in ERD wells, SPE 181947-RU, 2016, https://doi.org/10.2118/181947-RU

Low efficiency development areas of carbonate reservoir by traditional methods are located in Central Khoreyver Uplift region. In the main such areas are observed in formation D3fmIV, that widely propagate on the many oil fields of this region. This formation has high degree of compartmentalization and heterogeneity of reservoir properties. Such facts make difficult development of formation D3fmIV by vertical wells. Thus, application of more complicate well completion technologies may increase development efficiency of the such areas. This paper presents analysis of modern well completion technologies for low density reserves area development, selection criteria for pilot areas, efficiency estimation for selected pilot areas by simulation model. Identification of oil fields that have sufficient amount reserves located in low density reserves areas was carried out based on routine data collection during production period and production logging analysis. Further, field, that has high degree of exploration maturity and surface facilities opportunity, was selected for pilot areas estimation. Pilot area selection carried out based on criteria associated sufficient amount reserves presence, non-depleted reservoir pressure and availability of well test and production logging data for reduction of risk. Efficiency estimation of complicate well completion technology application was carried out by analytical methods and simulation model with local grid refinement and taking into account well test and production logging data. Start parameters of wells with complicate completion, estimated by simulation model with local grid refinement good match up with results calculated by analytical methods. In result “Fishbone” technology became the most effective for development of high compartmentalization and heterogeneous carbonate reservoir. The main advantage of this technology in comparison with multi-fractured horizontal well is unlimited effect duration. Commonly known fracture stimulation duration usually continue 2-3 years. However, application “Fishbone” technology for oil fields located in Central Khoreyver Uplift region is very limited due to absent in local market. In result, multi-fractured horizontal well completion technology was recommended for efficiency increasing of low density reserves areas development. The most efficient technologies are determined for low density reserves areas located in Central Khoreyver Uplift region: the most efficient well completion and its parameters was identified with taking into account technical limits. Developed workflow may be used for fields with low density reserves areas located in other regions.

References

1. Karpov V.B., Parshin N.V., Ryazanov A.A., Advanced development of hard-to-recover reserves using multistage hydraulic fracturing (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 3, pp. 96–100.

2. BazitovM.V., Golovko I.S. , D.A. Konosov et al., First fishbone well drilling at Vankorskoe field (In Russ.), SPE 176510-MS, 2015.

3. Algeroy J., Pollock R., Equipment and operation of advanced completions in the M-15 Wytch Farm multilateral well, SPE 62951-MS, 2000.

4. Dossary A.S., Mahgoub A.A., Challenges and achievements of drilling maximum reservoir contact (MRC) wells in Shaybah field, SPE 85307-MS, 2003.

5. Bouldin B., Turner R., Bellaci I. et al., Intelligent completion in laterals becomes a reality, SPE 183949-MS, 2017.

6. Dulaijan A., Shenqiti M., Ufondu K. et al., A decade of experience using intelligent completions for production optimization and water shut-off in multilateral wells in the world's largest oilfield, SPE 184629-MS, 2017.

7. Liu Hai, Luo Yin, Li Xianwen et al., Advanced completion and fracturing techniques in tight oil reservoirs in Ordos Basin: A workflow to maximize well potential, SPE 158268-MS, 2012.

8. Zaikin I.P., Kempf K.V., Shkarin D.V., Experience in constructing a multilateral well in Zarubezhneft JSC (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 8, pp. 21–24.

9. Bagmanov R.D., Fedorchenko G.D., Afanas'ev I.S., Ayushinov S.P., Challenges of horizontal well drilling technology implementation on carbonate reservoirs in Zarubezhneft JSC (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 6, pp. 72–86.

10. Rice J.K., Jorgensen T., Waters J.W., First installation of efficient and accurate multilaterals stimulation technology in carbonate reservoir, SPE 171804-MS, 2014.

11. Akhkubekov A.E., Vasiliev V., Acid tunneling technology: Application potential in Timano-Pechora carbonates (In Russ.), SPE 135989-MS, 2010.

12. Elliott S., Tethys petroleum on radial drilling technology case history: North Urtabulak, URL: https://rogtecmagazine.com/tethys-petroleum-on-radial-drilling-technology-case-history-north-urtabul...

Cyclic waterflooding as one of the methods of enhanced oil recovery is a fairly effective technology to maintain the level of oil production in developed fields. In 2010 Udmurtneft JSC started the using of the dual injection equipment. The equipment allows cyclic injection for only one selected production zone. With an integrated approach to the management of cyclic waterflooding, one of the tasks is to assess the actual efficiency of cyclic injection over past periods, for which it is recommended to use daily production data for impacted production wells. To assess the actual effectiveness of cyclic injection based on daily production data, information is required on the dates of its beginning and end.

The author developed an algorithm to recognize cyclic injection mode of water injection well based on daily reports of its rate. The algorithm is based on the moving average for adaptive selection of the main trend in the injection. On the one hand, it allows identifying the cyclic mode for wells, which completely shut in the corresponding half-cycle (zero injection rate). On the other hand, the algorithm can also be used for wells with dual injection equipment, for which cyclic injection is carried out only within one of the production zones, for the other production zone the injection is carried out in normal mode (the variation of injection rate about its mean). The proposed algorithm makes it possible with 90% reliability to recognize cyclic injection intervals in wells with stop of water injection both in all opened production zones and in a part of them.

References

1. Ibragimov N.G., Khisamutdinov N.I., Taziyev M.Z. et al., Sovremennoye sostoyaniye tekhnologiy nestatsionarnogo (tsiklicheskogo) zavodneniya produktivnykh plastov i zadachi ikh sovershenstvovaniya (The current state of unsteady (cyclic) flooding technology and problems of their improving), Moscow: Publ. of VNIIOENG, 2000, 112 p.

2. Sharbatova I.N., Surguchev M.L., Tsiklicheskoye vozdeystviye na neodnorodnyye neftyanyye plasty (Cyclical effects on heterogeneous oil layers), Moscow: Nedra Publ., 1988, 121 p.

3. Tsepelev V.P., Nasyrov V.A., Kachurin S.I., Analysis of the effectiveness of the use of non-stationary waterflooding at the fields of Udmurtneft OAO (In Russ.), Territoriya “NEFTEGAZ”, 2011, no. 4, pp. 30–34.

4. Borovskiy I.A., The technology of dual injection (In Russ.) Geologiya, geografiya i global'naya energiya, 2010, no. 4(39), pp. 99-103.

5. Sidel'nikov K.A., Tsepelev V.P., Integrated cyclic waterflooding management in the oil fields of Udmurtneft OJSC (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 6, pp. 112-116.

6. Sidel’nikov K.A., Automated search of injection wells with cyclic change of injection according to dayly data (In Russ.), Avtomatizatsiya, telemekhanizatsiya i svyaz’ v neftyanoy promyshlennosti, 2016, no. 3, pp. 30–34.

Tyumen suite is a low permeable reservoir with difficult geological aspects. Sensitivity of production well to work start reservoir pressure maintenance system in low permeable reservoir conditions is less than traditional reservoirs thus flow back oil production of injection wells is compare with efficiency of reservoir pressure maintenance system. In this connection injection wells flow back period issue is actual for technical and economics indexes enhance. The conversion to injection decisions are based on production rate decline analysis and results of hydrodynamic modeling. For this purpose was created hydrodynamic three phase model which segment was used for multiple option calculations. The goal of multiple option calculation is injection wells flow back optimum period definition. The efficiency of reservoir pressure maintenance system was estimated for each injection well with different flow back period. Each injection well has its own flow back optimum period. With conventional approach, that means many variations and computation which number depends on the number of injection wells and flow back period detail. This way is complicated for continuously updated geological information from drilling operations. An express method for injection wells flow back optimum period definition with minimal number of hydrodynamic calculations was proposed. Definition of reaction intensity between injection well and environment wells based method. The express method give closed to optimum result with significant reduction in labor costs.

References

1. Smagina T.N., Volkov M.A., Rybak V.K. et al., Issues of studying oil pools in Tyumen suite, Krasnoleninskoye field (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2010, no. 11, pp. 24–27.

2. Chusovitin A.A., Gnilitskiy R.A., Smirnov D.S. et al., Evolution of engineering solutions on the development of Tyumen suite oil reserves on an example of Krasnoleninskoye oilfield (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 5, pp. 54–58.

3. Shupik N.V., Povyshenie effektivnosti ploshchadnykh sistem zavodneniya nizkopronitsaemykh plastov Zapadnoy Sibiri (Improving the efficiency of pattern waterflooding of low-permeability formations in Western Siberia): thesis of candidate of technical science, Moscow, 2017.

4. Karpov V.B. et al., Tight oil field development optimization based on experience of Canadian analogs (In Russ.), SPE 182572-RU, 2016.

5. Galeev R.R., Zorin A.M., Kolonskikh A.V. et al., Optimal waterflood pattern selection with use of multiple fractured horizontal wells for development of the low-permeability formations (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2013, no. 10, pp. 62–65.

6. Baykov V.A., Zhdanov R.M., Mullagaliev T.I., Usmanov T.S., Selecting the optimal system design for the fields with low-permeability reservoirs (In Russ.), Neftegazovoe delo, 2011, no. 1, pp. 84–97.

An approach to solving the optimization problem for a multistage hydraulic fracturing (MHF) design is proposed. Free optimization parameters are set as follows: the length of the horizontal well, the number of fractures and the amount of proppant loaded in each fracture. Optimization targets are the maximum of the cumulative well production, the maximum of the net present value (NPV), and the minimum of fracturing costs. As an optimization algorithm, we use genetic algorithm NGSA-II, which requires calculating three related values at each iteration step: the fracture geometry, the post-fracture well production, and economy indicators. The approach proposed is illustrated by the case of the low-permeability oil reservoir under the following suggestions. It is assumed that the oil reservoir is rectangular, the horizontal well is positioned along the centerline of the reservoir, and hydraulic fractures are placed on equal distance perpendicular to the wellbore and symmetric about it. In addition, all fractures are identical to each other. The geometric characteristics of fractures (length and width) are determined by the amount of proppant injected and are calculated by empirical relationships. To obtain the value of post-fracture well production, approximate analytical formulas that take into account the final conductivity of fractures are applied. The main economic indicator that characterizes the economic profitability of the MHF is the NPV-based income. The case studies for different values of the average permeability of the reservoir are carried out. The numerical results show that the dependence of NPV on the well production is not always linear. The results show that after certain adjustment of the algorithm to parameters of the particular field, the model can be used as a tool for planning of the field development.

References

1. Economides M.J., Oligney R.E., Valko P.P., Unified fracture design: Bridging the gap between theory and practice, Texas: Orsa Press Alvin, 2002, 262 p.

2. Marongiu-Porcu M., Economides M.J., Holditch S.A., Economic and physical optimization of hydraulic fracturing, J. Nat. Gas. Sci. Eng., 2013, V. 14, pp. 91–107.

3. Rahman M.M., Rahman M.K., Rahman S.S., An integrated model for multiobjective design optimization of hydraulic fracturing, J. Petrol. Sci. Eng., 2001, V. 31, pp. 41–62.

4. Rahman M.M., Rahman M.K., Rahman S.S., Multicriteria hydraulic fracturing optimization for reservoir stimulation, Pet. Sci. Technol., 2003, V. 21, pp. 1721–1758.

5. Deb K., Agrawal S., Pratap A. et al., A fast and elitist multiobjective genetic algorithm: NSGA-II, IEEE Trans. Evol. Comp., 2002, V. 6, pp. 182–197.

6. Shel E. et al., Retrospective analysis of hydrofracturing with the dimensionless parameters: Comparing design and transient tests (In Russ.), SPE 191707-18RPTC-MS, 2018, https://doi.org/10.2118/191707-18RPTC-MS.

7. Shel E.V., Paderin G.V., Kabanova P.K., Testing methodology for the hydrofracturing simulator (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 12, pp. 42–45.

8. Elkin S.V., Aleroev A.A., Veremko N.A. et.al., Flowrate calculation model for fractured horizontal well depending on frac stages number (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 1, pp. 64–67.

9. Elkin S.V., Aleroev A.A., Veremko N.A. et.al., Accounting for dimensionless conductivity in express calculation of flow-rate in a well after multi-stage hydraulic fracturing (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 12, pp. 110–113.

The article presents a comparative analysis of three methods for determining the reservoir filtration parameters: the traditional one, based on recording and processing the pressure build-up curve, and two new methods – pressure stabilization curve and production analysis. The method, based on the processing of pressure build-up curves, is theoretically justified; its reliability is confirmed by a long-term history of practical application. The predominant characteristic of the methods of the pressure stabilization curve and production analysis is the lack of a technological stage of a long well shutdown. However, it seems necessary to assess the reliability of the results shown by these methods, in comparison with the traditional method of pressure build-up curve. To solve the problem, we used materials from the records of bottomhole pressure and fluid flow rates in wells of Perm region fields. The pressure build-up and pressure stabilization curves were processed in the KAPPA Workstation v5.20.01 software package (Saphir module), the same software product (Topaz module) was used to process the production data. As a result of the analysis, we can conclude that when comparing the results high convergence was found and the error between the values was less than 5%. Thus, it is possible to use the methods of the pressure stabilization curve and production analysis for determining the parameters of low-permeable reservoirs, when this cannot be done using the pressure build-up curve because of poor data quality (under-restored pressure recovery curves), and based on the reservoir information it is possible to refine the hydrodynamic model and optimize wells operating modes.

References

1. Gulyaev D.N., Ipatov A.I., Kremenetskiy M.I. et al., Reservoir management by long-term downhole production monitoring on the example of Western Salymskoye oilfield (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2012, no. 12, pp. 36–39.

2. Davydova A.E., Shchurenko A.A., Dadakin N.M. et al., Well testing design development in carbonate reservoir (In Russ.), Izvestiya Tomskogo politekhnicheskogo universiteta. Inzhiniring georesursov = Bulletin of the Tomsk Polytechnic University. Geo Assets Engineering, 2019, V. 330, no. 6, pp. 68–79.

3. Latysheva M.V., Ustinova Yu.V., Kashevarova V.V., Potekhin D.V., Improvement of hydrodynamic simulation using advanced techniques of hydrodynamic well data processing (exemplified by Ozernoe field) (In Russ.), Vestnik Permskogo natsional'nogo issledovatel'skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo, 2015, no. 14, pp. 73–80.

4. Galkin V.I., Ponomareva I.N., Cherepanov S.S., Development of the methodology for evaluation of possibilities to determine reservoir types based on pressure build-up curves, geological and reservoir properties of the formation (case study of famen deposits of Ozernoe field) (In Russ.), Vestnik Permskogo natsional'nogo issledovatel'skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2015, V. 14, no. 17, pp. 32–40.

5. Sergeev V.L., Nguen T.Kh.F., Models and algorithms for adaptive interpretation of combined well test data of intelligent wells (In Russ.), Izvestiya Tomskogo politekhnicheskogo universiteta. Inzhiniring georesursov = Bulletin of the Tomsk Polytechnic University. Geo Assets Engineering, 2018, V. 329, no. 10, pp. 67–75.

6. Davydova A.E., Shchurenko A.A., Dadakin N.M. et al., Optimization of carbonate reservoir well testing (In Russ.), Vestnik Permskogo natsional'nogo issledovatel'skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2018, V. 17, no. 2, pp. 123–135.

7. Sergeev V.L., Dong V.Kh., Fam D.A., Adaptive interpretation of the results of horizontal well production testing using forecasting models (In Russ.), Izvestiya Tomskogo politekhnicheskogo universiteta. Inzhiniring georesursov = Bulletin of the Tomsk Polytechnic University. Geo Assets Engineering,, 2019, V. 330, no. 1, pp. 165–172.

8. Sergeev V.L., Vu K.D., Adaptive interpretation of pressure transient tests of horizontal wells with pseudoradial flow identification (In Russ.), Izvestiya Tomskogo politekhnicheskogo universiteta. Inzhiniring georesursov = Bulletin of the Tomsk Polytechnic University. Geo Assets Engineering,, 2017, V. 328, no. 10, pp. 67–73.

9. Sergeev V.L., Dong V.Kh., Identification of filtration flow regimes in hydrodynamic studies of horizontal wells with hydraulic fractures (In Russ.), Izvestiya Tomskogo politekhnicheskogo universiteta. Inzhiniring georesursov = Bulletin of the Tomsk Polytechnic University. Geo Assets Engineering, 2019, V. 330, no. 3, pp. 103–110.

10. Fei Wang, Shicheng Zhang, Pressure-buildup analysis method for a post-treatment evaluation of hydraulically fractured tight gas wells, Journal of Natural Gas Science and Engineering, 2016, V. 35, pp. 753–760.

11. Yi-Zhao Wan, Yue-Wu Liu, Fang-Fang Chen et al., Numerical well test model for caved carbonate reservoirs and its application in Tarim Basin, China, Journal of Petroleum Science and Engineering, 2018, V. 161, pp. 611–624.

12. Iktisanov V.A., Sakhabutdinov R.Z., Evaluation of effectiveness of EOR and bottomhole treatment technologies using rate transient analysis (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 5, pp. 77–76.

According to the literature and our own experimental data, the known types of residual oils, methods for determining the predominant type of residual oils for the oil reservoir targeted stimulation in order to increase oil recovery are considered. The qualitative characteristics of the properties of residual oils, by which it is possible to assess their changes by modern technical means are revealed. At residual oils additional displacement from the water-flooded reservoir, the phase state of the reservoir fluids, due to the redistribution of components between two reservoir fluids (reservoir water and residual oil), as well as a change in the phase state depending on the saturation of the oil - solid phase and wax precipitation in reservoir conditions - play an important role. Examples of studying at a particular field not only the composition of the residual oil, but also the degree of development of reservoir reserves under conditions of its washing with fresh water, when oil wells geophysical prospecting can't provide reliable information about the oil saturation of different intervals of the reservoir in the flooded area, are given. The change in the phase state (wax precipitation in reservoir conditions) of surface samples and degassed deep oil samples taken from the same oil well in different years are given. It is recommended for the analysis of changes in the properties of reservoir fluids to create an operational data bank with a data monitoring function, the ability to build maps and histograms of the distribution of physical and chemical properties both along the strike and along the depth of the beds.

The obtained on the basis of areal and temporary monitoring information on changes in the properties of reservoir fluids allows to identify the oil reservoir zones with varying degrees of oil saturation and assess the quality of residual oils, which makes it possible to monitor the state of the developed deposit and adopt optimal management decisions.

References

1. Surguchev M.L., Gorbunov A.T., Zabrodin D.P. et al., Metody izvlecheniya ostatochnoy nefti (Residual oil recovery methods), Moscow: Nedra Publ., 1991, 347 p.

2. Ashmyan K.D., Vol'pin S.G., Kovaleva O.V., To the question about the development of stranded (In Russ.), Trudy NIISI RAN, 2019, V. 1, pp. 23–28.

3. Kovalev A.G., Kovaleva O.V., Kozlov G.A., Maslov S.A., Prospects for the isolation of commercial reservoirs with in-circuit flooding according to core analysis (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 1989, no. 10, pp. 78–79.

4. Namiot A.Yu., Rastvorimost' gazov v vode (Solubility of gases in water), Moscow: Nedra Publ., 1991, 167 p.

5. Nafikov A.A., Khisametdinov M.R., Fedorov A.V. et al., Changes in composition and properties of crude oil resulting from application of enhanced oil recovery technologies (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 9, pp. 100–103.

6. Titov V.I., Zhdanov S.A., Changes in the composition of reservoir oils in the development of fields (Overview) (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 1988, no. 8, pp. 26–28.

7. Kovaleva O.V., Sostav i svoystva ostatochnoy nefti v obvodnennykh zonakh produktivnykh plastov (Composition and properties of residual oil in watered areas of productive formations): thesis of candidate of technical science, Moscow, 1988.

8. Kovaleva O.V., Vliyanie razlichnykh faktorov na izmenenie sostava ostatochnoy nefti (The influence of various factors on the change in the composition of the residual oil), Collected papers “Nauchno-tekhnicheskie problemy razrabotki i obustroystva neftyanykh mestorozhdeniy” (Scientific and technical problems of oil fields development and field facilities), Proceedings of Giprovostokneft', 1990, pp. 103–114.

9. Kovaleva O.V., Ob izmenenii svoystv ostatochnoy nefti v protsesse razrabotki mestorozhdeniy metodom zavodneniya (Changes in the properties of residual oil in the process of field development by water flooding), Proceedings of All-Union Conference on Oil Chemistry, Tomsk, 1988, pp. 138–139.

10. Blyumentsev A.M., Kononenko I., Operativnyy monitoring razrabotki neftyanykh mestorozhdeniy na pozdney stadii s tsel'yu povysheniya izvlecheniya nefti (Operational monitoring of the development of oil fields at a late stage in order to increase oil recovery), Proceedings of International Scientific and Practical Conference, Kazan': FEN Publ., 2013, 408 p.

11. Eksperimental'nye metody issledovaniya parafinistykh neftey (Experimental methods for the study of paraffin oils): edited by Ashmyan K.D., Moscow: Publ. of VNIIneft', 2004, 108 p.

12. Namiot A.Yu., Fazovye ravnovesiya v dobyche nefti (Phase equilibria in oil production), Moscow: Nedra Publ., 1976, 180p.

13. Ashmyan K.D., Vliyanie mineralizatsii vody na vzaimnuyu rastvorimost' vody i komponentov plastovykh neftey v usloviyakh neftyanykh zalezhey na bol'shikh glubinakh (The effect of water salinity on the mutual solubility of water and components of reservoir oils in the conditions of oil deposits at great depths): thesis of candidate of technical science, Moscow, 1985.

14. Ashmyan K.D., Kovaleva O.V., Nikitina I.N., Method for evaluating the paraffin phase state in raw oil (In Russ.), Vestnik TsKR Rosnedra, 2011, no. 6, pp. 11–14.

For the design of new technologies aimed at increasing the efficiency of the production of hard-to-recover reserves, it is necessary to take into account factors that may affect their implementation. These factors may include the pore structure, the physical and physicochemical properties of reservoir fluids, as well as their variability within the development object. The authors determined the basic laws of the variability of the molecular mass distribution of alkanes based on chromatographic studies of the composition of high-viscosity oil of the Bobrikovian-Radaevian horizon of the Vishnevo-Polyanskoe field. The object of the study is the Vishnevo-Polyanskoe high-viscosity oil field, which is located on the eastern side slope of the Melekess Depression and was put into development in 1988. The main object of development is the Bobrikovian-Radaevian horizon. The Vishnevo-Polyanskoe field is characterized by a rather low oil recovery factor of 0,09. Consequently, this highly viscous oil field can be considered as a priority object for the application of technologies aimed at increasing oil production. In connection with the above, for the selection of effective reservoir stimulation methods, it is necessary to study the patterns of manifestation of microprocesses occurring in the reservoir. The analysis for study the dynamics of the composition of the moving part of the remaining oil in place of the Vishnevo-Polyanskoe field of high-viscosity oil samples taken from 20 production wells with a frequency of 7 days was carried out. In general, the oil of the Bobrikovian-Radaevian horizon of the Vishnevo-Polyanskoe field is characterized by close molecular mass distribution curves of n-alkanes C10-C40. Analysis of the molecular mass distribution of n-alkanes is characterized by a monotonic decrease in hydrocarbon content from C14 to C34. The oil of the Vishnevo-Polyanskoe field has a single-mode character with a maximum in C14. The group of heavy components C21-C40 is characterized as heterogeneous, which may indicate a decrease in the stability of structural formations and precipitation of aggregates from high-molecular hydrocarbons, gums and asphaltenes in the reservoir and bottomhole zone due to changes in thermodynamic conditions.

References

1. Muslimov R.Kh., Abdulmazitov R.G., Khisamov R.B. et al., Neftegazonosnost' Respubliki Tatarstan. Geologiya i razrabotka neftyanykh mestorozhdeniy (Oil and gas bearing of the Republic of Tatarstan. Geology and development of oil fields), Part 2, Kazan': FEN Publ., 2007, 524 p.

2. Yusupova T.N., Ganeeva Yu.M., Romanov G.V., Barskaya E.E., Fiziko-khimicheskie protsessy v produktivnykh neftyanykh plastakh (Physical and chemical processes in the productive oil reservoirs), Moscow: Nauka Publ., 2015, 412 p.

3. Kayukova G.P., Romanov G.V., Lukyanova R.G., Sharipova N.S., Organicheskaya geokhimiya osadochnoy tolshchi i fundamenta territorii Tatarstana (Organic geochemistry of sedimentary strata and basement of the territory of Tatarstan), Moscow: GEOS Publ., 2009, 487 p.

4. Surguchev M.L., Vtorichnye i tretichnye metody uvelicheniya nefteotdachi plastov (Secondary and tertiary methods of enhanced oil recovery), Moscow: Nedra Publ., 1985, 308 p.

Hydraulic fracturing is one of the most common technologies aimed at increasing the productivity of wells. A detailed analysis of the experience of conducting hydraulic fracturing accumulated for a particular region will help to develop approaches to the successful implementation of the method. In particular, determining size and direction of the fracture is of great interest for the theory and practice of oil production. One of the modern methods to determine the spatial location of a hydraulic fracture and its dimensions is microseismic monitoring. However, not every hydraulic fracturing operation can be accompanied by microseismic monitoring. Thus, in some cases, the application of this control method is hampered by the presence of adverse seismic and geological conditions that impede the passage of waves. It is also necessary to take into account the rise in the cost of the fracturing procedure when it is accompanied by microseismic monitoring. In this regard, it seems relevant to develop a method that allows, according to the integrated processing of geological field material, to solve this problem.

The article presents the results of the data analysis on wells of the Perm region, the hydraulic fracturing of which was accompanied by high-quality microseismic monitoring. For the same wells hydrodynamic research materials under unsteady conditions and production data for 12 months before and after hydraulic fracturing were attracted. A comprehensive analysis of these materials also made it possible to obtain crack parameters with a high degree of convergence with the results of microseismic monitoring. Thus, the article developed an approach to assess the results of hydraulic fracturing based on the use of data from field and hydrodynamic studies, which showed high convergence with the results of microseismic monitoring.

References

1. Voevodkin V.L., Aleroev A.A., Baldina T.R. et al., The evolution of the hydraulic fracturing technology on the fields of Perm region (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 11, pp. 108–113.

2. Cherepanov S.S., Chumakov G.N., Ponomareva I.N., Results of applying acidic hydraulic fracturing with proppant in the Tournaisian-Famennian reserves at the Ozernoe field (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, 2015, no. 16, pp. 70–76.

3. Votinov A.S., Drozdov S.A., Malysheva V.L., Mordvinov V.A., Recovery and increase of the productivity of wells of Kashirskiy and Podolskiy reservoirs of the certain Perm region oil field (In Russ.), Vestnik Permskogo natsional'nogo issledovatel'skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2018, V. 18, no. 2, pp. 140–148, DOI: 10.15593/2224-9923/2018.4.4.

4. Aleksandrov S.I., Gogonenkov G.N., Pasynkov A.G., Passive seismic monitoring as a tool of hydrofrac geometry determination (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2007, no. 3, pp. 51–53.

5. Barkhatov E.A., Yarkeeva N.R., The efficiency of multizone hydraulic fracturing in horizontal well (In Russ.), Izvestiya Tomskogo politekhnicheskogo universiteta. Inzhiniring georesursov = Bulletin of the Tomsk Polytechnic University. Geo Assets Engineering, 2017, V. 328, no. 10, pp. 50–58.

6. Jianming He, Chong Lin, Xiao Li et al., Initiation, propagation, closure and morphology of hydraulic fracturing in sandstone cores, Fuel, 2017, V. 208, pp. 65–70, DOI: 10.1016/j.fuel.2017.06.080..

7. Galkin V.I., Koltyrin A.N., Kazantsev A.S. et al., Development of a statistical model aimed at prediction of efficiency of proppant hydraulic fracturing of a formation, based on a reservoir geological-technological parameters, for Vereiskian carbonate oil- and gas-bearing complex (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2017, no. 3, pp. 48–54.

8. Galkin V.I., Ponomareva I.N., Koltyrin A.N., Development of probabilistic and statistical models for evaluation of the effectiveness of proppant hydraulic fracturing (on example of the Tl-Bb reservoir of the Batyrbayskoe field) (In Russ.), Vestnik Permskogo natsional'nogo issledovatel'skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2018, V. 17, no. 1, pp. 37–49.

9. Tarek A. Ganata, Meftah Hrairi, A new choke correlation to predict flow rate of artificially flowing wells, Journal of Petroleum Science and Engineering, 2018, V. 171, pp. 1378–1389.

10. Nurgaliev R.Z., Mukhliev I.R., Sagidullin L.R. et al., Peculiarities of wells interference influence on the efficiency of hydraulic and gaz-dynamic fracturing of a formation (In Russ.), Neftepromyslovoe delo, 2018, no. 3, pp. 29–34.

11. Mukhametshin V.V., Rationale for trends in increasing oil reserves depletion in Western Siberia cretaceous deposits based on targets identification (In Russ.), Izvestiya Tomskogo politekhnicheskogo universiteta. Inzhiniring georesursov = Bulletin of the Tomsk Polytechnic University. Geo Assets Engineering, 2018, V. 329, no. 5, pp. 117–124.

12. Mirzadzhanzade A.Kh., Tekhnologiya i tekhnika dobychi nefti (Technology and oil production technology), Moscow: Nedra Publ., 1986, 382 p.

13. Chornyy A.V., Kozhemyakina I.A., Churanova N.Yu. et al., Analysis of wells interaction based on algorithms of complexing geological and field data (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 1, pp. 36–39.

14. Chekalyuk E.B., Osnovy p'ezometrii zalezhey nefti i gaza (Basics of piezometry of oil and gas deposits), Kiev: Gosnauchtekhizdat Ukrainy Publ., 1961, 286 p.

One of the major problems of development of fields with gas caps and oil rims is breakthrough of the gas to the bottom holes of producing wells. This problem becomes bigger if the gas is re-injected into the gas cap in order to maintain the reservoir pressure. Because of the big difference in mobility ratio, the gas "plugs" the oil in the reservoir and in the well bore and that materially reduces the oil production rates. Considering gas processing facilities limitation, the gas production growth the load increases and restricts the total volume of associated gas production at the field. This results in production cuts or shut-ins of the wells with high gas-to-oil ratio (GOR) and oil production losses. The gas processing infrastructure expansion option is not economical and it requires long time for design and construction. Another approach to solve above mentioned problem is to run well work activities for shutting off gas break-through intervals in the producer wells for GOR reduction. This article reveals unique experience of Rosneft Oil Company shutting off gas break-through intervals at the Northern edge of Chaivo oil-gas-condensate field on Sakhalin Island offshore. Rosneft has identified and shouted off gas break-through intervals in the extended reach horizontal well at 9800 m MD. The article reviews the equipment and the technology that used for production logging tests (PLT), the approach to candidate wells selection based on PLT, the equipment and activities for gas shutoff; also, oil production results after gas shutoff are provided.

References

1. Ganichev D., Makarov E., Bardin V., Bovykin A., Planning and results of ultra extended reach well drilling in the Chayvo field, SPE 181897-MS, 2016, https://doi.org/10.2118/181897-MS.

2. Gupta V.P., Sanford S.R., Mathis R.S. et al., Case history of a challenging thin oil column extended reach drilling (ERD) development at Sakhalin, SPE 163487-MS, 2013, https://doi.org/10.2118/163487-MS.

3. Molloy R., Sakhalin gas shut-off workovers: A case history of zonal isolation at record depth, SPE 163482-MS, 2013, https://doi.org/10.2118/163482-MS.

4. Sheiretov T., Wireline tractors and mechanical services tools: comparative study of technical solutions, SPE 179044-MS, 2016, https://doi.org/10.2118/179044-MS.

Vankor oil and gas condensate field is one of the largest in the oil and gas region of the Nadym-PUR-Taz basin of Western Siberia. Development of the field began in 2009 and is carried out by a system of horizontal wells, with a horizontal section length of up to 1100 m. directional wells. To maintain high rates of field development, the issue of restoration and increase of productivity of horizontal wells becomes relevant. One of the effective methods to restore the productivity of wells is the treatment of the bottom-hole zone with composite compositions including solvents and acids. This article discusses the method of selection of technologies and reagents to restore the productivity of horizontal wells on the example of the Vankor field. The methodology for the selection of technologies and compositions consists of the following steps: study of acid compositions; exploration of changes in the filtration characteristics of an oil-saturated porous medium (cores) when exposed to an acid composition; selection of the target reagent; compatibility of bottom-hole formation zone treatment reagents with reservoir fluids; consumption rate of reagents for carrying out bottom-hole formation zone treatment; the time required to remove (destroy, dissolve) the colmatant; a method for the delivery of a reagent to the place of sediment colmatant; products formed when reagents act on colmatant; removal of reaction products from the well; risks of incompatibility of reagents with each other and with formation fluids; materials and technology for selective processing of a given interval. The proposed methodology for the selection of bottom-hole formation zone treatment technology in horizontal wells was tested at the VNGKM. 20 well treatments were carried out on the main reservoirs, the specific consumption of reagents varied from 6 dm3/m to 32 dm3/m. The main results: the minimum increase in oil production was 11 tons/day, the average increase in oil production was 24 tons/day; there were no complications during the operation of wells after the bottom-hole formation zone treatment; the duration of the effect depends on the specific consumption of reagents, a stable effect is obtained for a specific consumption of more than 8 dm3/m. The results of the treatments confirmed the effectiveness of the proposed methodology. Based on the results of the field work, it was decided to introduce the proposed bottom-hole formation zone treatment technologies at the Vankor field.

References

1. Krinin V.A., Stroenie i stratigraficheskoe polozhenie plastov-kollektorov nizhnekhetskogo produktivnogo gorizonta v severo-vostochnoy chasti Zapadno-Sibirskoy neftegazonosnoy provintsii (The structure and stratigraphic position of reservoir layers of the Lower Khetian productive horizon in the north-eastern part of the West Siberian oil and gas province), Proceedings of Scientific and Practical Conference “Perspektivy razvitiya neftegazodobyvayushchego kompleksa Krasnoyarskogo kraya” (Prospects for the development of the oil and gas complex of the Krasnoyarsk Territory), Krasnoyarsk: KNIIGiMS, 2007.

2. Fokin P.A., Demidova V.R., Yatsenko V.M. et al., Composition and formation conditions of pay zones in the lower Cretaceous Nizhnyaya Kheta and Yakovlevo formations within the Vankor oil-and-gas field (In the Northeast of West Siberia) (In Russ.), Vestnik Moskovskogo universiteta. Ser. 4. Geologiya = Moscow University Geology Bulletin, 2008, no. 5, pp. 12–18.

3. Civan F., Near-wellbore formation damage by inorganic and organic precipitates deposition, Ch. 24, In: Reservoir Formation Damage, 2016, 1084 p.

4. Civan F., Reservoir stress-induced formation damage: formation compaction, subsidence, sanding tendency, sand migration, prediction and control, and gravel-pack damage. Ch. 15, In: Reservoir Formation Damage, 2016, pp. 419–443.

5. Valekzhanin I.V., Rezvova K.K., Akhtyamov A.R. et al., An integrated approach to the prevention of scale in terms of the Vankor field (In Russ.), Ekspozitsiya Neft' Gaz, 2015, no. 5(44), pp. 24–28.

6. Abdrakhmanov G.S., Yusupov I.G., Orlov G.A. et al., Isolation of water production zones in directional and horizontal wells (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2003, no. 2, pp. 44–47.

7. Akimov O.V., Gusakov V.N., Zdol'nik S.E. et al., Well kill technologies with fluid loss control for hydro-fractured wells under AHFP and ALFP Conditions (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2010, no. 2, pp. 92–95.

The concept of conscious use of adaptive parameters when determining hydraulic losses in pipes originates from A. Darcy’s works. It was shown using the basis of the retrospective analysis of scientific works in the field of hydraulic calculation of pipelines of the XVIII-XX centuries. However, use of coefficient of the equivalent roughness as the universal adaptive parameter does not allow reducing to a reasonable minimum a divergence of estimated dependences with the experimental values of coefficients of hydraulic losses of oil pipelines. And even the increased computational capabilities of computer technology did not allow to improve the accuracy of hydraulic calculations performed according to the formulas of classical hydrodynamics. Without relying on the future success in the development of adequate multiphase models for oil and oil product pipelines, it is necessary to recognize the most effective adaptive approach to the assessment of hydraulic friction parameters according to the operation data from the technological site. It was shown that it is acceptable in this case to adapt the coefficients in the generalized Leibenson equation for the coefficient of hydraulic friction according to the operation of each specific oil pipeline. For further improvement of the technological calculations accuracy, it is necessary to use the methodology of multiphase fluid flow in the relief pipeline, taking into account the accumulation and migration of water and gas accumulations.

Generalization of the current trends in hydrodynamics study of oil flows in pipelines shows the basic opportunity to receive satisfactory convergence of settlement and actual friction losses (±10-15%) by solution of the inverse problems of fluidmechanics, applying adaptation algorithms in two parameters.

The examples received by data processing from technological sites of operating oil pipelines for equation types of Darcy – Weisbach and Leibenson are given.

References

1. Kutukov S.E., Gol'yanov A.I., Chetvertkova O.V., The establishment of pipeline hydraulics: retrospective of researches of hydraulic losses in pipes (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 7, pp. 128–133.

2. Chernikin V.A., Chernikin A.V., Generalized formula for calculating the friction factor of pipelines for light oil products and lowviscosity oils (In Russ.), Nauka i tekhnologii truboprovodnogo transporta nefti i nefteproduktov, 2012, no. 4 (8), pp. 64–66.

3. Tsal R.J., Altshul-Tsal friction factor equation, Heating, Piping and Air Conditioning, 1989, no. 8, pp. 30–45.

4. Brkić D., Review of explicit approximations to the Colebrook relation for flow friction, Journal of Petroleum Science and Engineering, 2011, V. 77, no. 1, pp. 34–48.

5. Swamee P.K., Jain A.K., Explicit equations for pipe-flow problems, Journal of the Hydraulics Division, 1976, V. 102, no. 5, pp. 657–664.

6. Eck B., Technische Stromungslehre, New York: Springer, 1973, 324 p.

7. Round G.F., An explicit approximation for the friction factor-Reynolds number relation for rough and smooth pipes, The Canadian Journal of Chemical Engineering, 1980, V. 58, pp. 122–123.

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9. Zeghadnia L., Robert J.L., Achour B., Explicit solutions for turbulent flow friction factor: A review, assessment and approaches classification, Ain Shams Engineering Journal, 2019, no. 10, pp. 243–252.

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11. Kutukov S.E., Shammazov A.M., The hydrodynamic conditions of the existence of water accumulation in the oil pipeline (In Russ.), Problemy sbora, podgotovki i transporta nefti i nefteproduktov, 2003, V. 62, pp. 68–75.

12. Kutukov S.E., Bakhtizin R.N., Shammazov A.M., Gas congestion influence on pipeline system curve (In Russ.), Neftegazovoe delo, 2003, no. 1, URL: http://ogbus.ru/article/view/ocenka-vliyaniya-gazovogo-skopleniya-na-xarakteristiku-truboprovoda.

13. Kutukov S.E., Bazhaykin S.G., Mukhametshin G.R., Description of a pipeline section with water accumulation (In Russ.), Problemy sbora, podgotovki i transporta nefti i nefteproduktov, 2016, no. 4 (106), pp. 118–125.

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

15. Kutukov S.E., Bazhaykin S.G., Mukhametshin G.R., Description of a pipeline section with water accumulation (In Russ.), Problemy sbora, podgotovki i transporta nefti i nefteproduktov, 2016, no. 4 (106), pp. 118–125.

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

The article describes the experience of checking the conclusions of the survey of the technical condition of facilities at hazardous production facilities of oil refining and petrochemical industry, performed by subcontractors. Considered in detail the individual moments, the joint account which would enable the authors of these opinions to avoid misconceptions, to improve the quality and completeness of the surveys: changing the requirements of standards for loads; as well as the geometrical characteristics of the rolling profiles of steel structures (including corrosion) for various time periods of construction and operation; it is noted that a mandatory part of the instrumental work during the survey of structures for further consideration of research results in verification calculations is the determination of the actual (residual) thickness of steel structure elements; determination of steel grades and the maximum permissible negative temperature of steel structures made of boiling steels, the use of which is currently prohibited; determination of the degree of neutralization (corrosion) of concrete in reinforced concrete structures and its impact on the state of reinforcement; determination of the state of supports and suspensions on pipelines and its impact on the construction of overpasses.

Issues and solutions for the examination of underground structures (shallow foundations, pile foundations) and the determination of the bearing capacity of pile foundations are addressed.

A comprehensive analysis of the technical condition of the structures will make it possible to make informed decisions on the further safe operation of the survey object, on the rationality of replacing old structures with new ones, or on the cost-effectiveness of the option to strengthen them, the possibility of additional loading of building structures during reconstruction or technical re-equipment, and also operation in monitoring mode.

References

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2. Tekhnologicheskiy reglament po primeneniyu nerazrushayushchego ekspress-kontrolya sploshnosti svay metodom “SONIK” (Technological regulations for the use of non-destructive express control of the pales integrity by the SONIC method), Moscow: Publ. of TsNIIS, 2002.

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