The theoretical foundations and methods for searching of unique and large hydrocarbon deposits at great depths of the sedimentary cover have not been sufficiently developed. In earlier publications, the authors proposed a geofluid dynamic concept for the formation of industrially significant accumulations of oil and gas at depths below 6 km. According to the authors, there is an isolated autoclave-type hydrocarbon system into the Devonian-Lower Permian seismic stratigraphical sequence within the central part of the Pre-Caspian oil-and-gas province. This system’s areal boundaries are determined by the areas of distribution of deep-sea sediments. The processes of generation and accumulation of hydrocarbons have their own specific features within the autoclave hydrocarbon system. The most important of them is the spatial-temporal coupling of the foci of generation and zones of accumulation of hydrocarbons. This feature excludes secondary migration of hydrocarbons from the ontogenetic chain of deposits formation. As a consequence, the question arises as to how the reservoirs are filled with liquid and gaseous hydrocarbons and the water is displaced out of the reservoirs. The article substantiates the mechanisms of accumulation of hydrocarbons for two types of oil and gas localizing objects – underwater fans (slope and deep-water basins) and inter-basin carbonate platforms. It is shown that at the initial stage of oil and gas accumulation in the terrigenous reservoirs of the submarine fan, two interrelated factors played a significant role in the reservation of the reservoir void space by hydrocarbons: the physically conditioned possibility of gas-hydrate’s formation and the pressure of the overlying water column in the basins as a factor preventing the destruction of gas hydrate accumulations. In carbonate reservoirs, an important factor is the generation of hydrocarbons due to the realization of the own oil and gas generation potential of the host rocks. This is accompanied by the processes of secondary epigenesis of reservoir rocks and seals under the aggressive influence of pore waters and gases generated in early catagenesis, including acidic ones. Detailing of ideas about the mechanisms of reservation of the void spaces of reservoirs located within the autoclave HCS, important in explaining the large-scale localization of oil and gas in deep-submerged reservoirs without involving the mechanism of secondary migration, which takes place in a number of salt basins. The article discusses the initial stage of the void space reservation of large-scale oil and gas accumulation in intra-basin carbonate structures, as well as deep-water slopes of the fan. The issue is of great importance for the development of geofluid dynamic exploration of large oil and gas fields at great depths.

References

1. Abukova L.A., Volozh Yu.A., Fluid geodynamics of deeply buried zones of oil and gas accumulation in sedimentary basins (In Russ.), Geologiya i geofizika = Russian Geology and Geophysics, 2021, V. 62, no. 8, pp. 1069‒1080, DOI: 10.15372/GiG2021132

2. Abukova L.A., Volozh Yu.A., Dmitrievskiy A.N., Antipov M.P., Geofluid dynamic concept of prospecting for hudrocarbon accumulations in the earth crust (In Russ.), Geotektonika, 2019, no. 3, pp. 79–91, DOI: https://doi.org/10.31857/S0016-853X2019379-91

3. Volozh Yu.A., Abukova L.A., Antipov M.P. et al., Utoclave type of the hydrocarbon systems in the Caspian oil and gas bearing province (Russia): Conditions of formation at great depth (In Russ.), Geotektonika, 2022, no. 6, pp. 1–19, DOI: 10.31857/S0016853X22060078

4. Volozh Yu.A., Abukova L.A., Rybal’chenko V.V., Merkulov O.I., Formation of oil and gas fields in deep hydrocarbon systems: Outline of a universal search concept (In Russ.), Geotektonika, 2022, no. 5, pp. 27– 49, DOI: 10.31857/S0016853X22050095

5. Volozh Yu.A., Bykadorov V.A., Antipov M.P. et al., On the boundaries and zoning of the Caspian oil and gas province (In Russ.), Georesursy = Georesources, 2021, V. 23, no. 1, pp. 60–69, DOI: https://doi.org/10.18599/grs.2021.1.6

6. S Khafizov S.F., Osipov A.V., Dantsova K.I. et al., Factors that determine the formation and preservation of accumulations of liquid hydrocarbons at depths of more than 5 km (In Russ.), Conference Proceedings, Geomodel 2020, Sep 2020, V. 2020, pp. 1 – 5, DOI: 10.3997/2214-4609.202050058

7. Khafizov S.F., Syngaevskiy P.E., Bakuev O.N., Shimanskiy V.V., On the question of the depths of the formation of alluvial fans (In Russ.), Izvestiya vysshikh uchebnykh zavedeniy. Neft’ i Gaz, 2003, no. 2(38), pp. 11–20.

8. Vassoevich N.B., Geodekyan A.A., Zor’kin L.M., Neftegazonosnye osadochnye basseyny (Oil and gas bearing sedimentary basins), In: Goryuchie iskopaemye: Problemy geologii i geokhimii naftidov (Fossil fuels: Problems of geology and geochemistry of naphthides): edited by . Vassoevich N.B., Moscow: Nauka Publ., 1972, pp. 14–24.

9. Kontorovich A.E., Bogorodskaya L.I., Mel’nikova V.M., Anaerobic transformations of organic material in ancient marine sediments (In Russ.), Izvestiya Rossiyskoy akademii nauk. Seriya geologicheskaya, 1974, no. 9, pp. 112–123.

10. Lisitsyn A.P., Lavinnaya sedimentatsiya i pereryvy v osadkonakoplenii v moryakh i okeanakh (Avalanche sedimentation and breaks in sedimentation in the seas and oceans): edited by Bogdanov Yu.A., Moscow: Nauka Publ., 1988, 309 p.

11. Burton Z.F.M., Dafov L.N., Testing the sediment organic contents required for biogenic gas hydrate formation: Insights from synthetic 3-D basin and hydrocarbon system modeling, Fuels, 2022, no. 3, pp. 555–562, DOI:10.3390/fuels3030033

12. Kroegera K.F., Plaza-Faverola A., Barnesc P.M., Pecherad I.A., Thermal evolution of the New Zealand Hikurangi subduction margin: Impact on natural gas generation and methane hydrate formation – A model study, Marine and Petroleum Geology, 2015, V. 63, pp. 97–114, DOI:10.1016/j.marpetgeo.2015.01.020

13. Deliya S.V., Abukova L.A., Abramova O.P., Popov S.N. et al., Features of collectors, underground and technical waters interaction during exploitation of Yu.Korchagin oil-gas-condensate field (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2013, no. 3, pp. 18–22.

14. Oreshkin I.V., The prospects of joint studying of Kazakh and Russian sectors of Precaspian megadepression (In Russ.), Nedra Povolzh’ya i Prikaspiya, 2018, V. 95, pp. 20–28.

15. Oreshkin I.V., Navrotskiy
O.K., Fossilization of organic matter, formation of oil and gas, and emigration
of hydrocarbons in carbonate rocks (In Russ.), Litologiya i poleznye iskopaemye
= Lithology and Mineral Resources., 2016, no. 2, pp. 168–177, DOI:

The observed situation with the multivariance of existing concepts of the Pre-Caspian depression formation is due to the fact that today there is no information on the material composition of the basement rocks in the Central Pre-Caspian Depression. Data about them have been obtained only on the basis of indirect methods (seismic data and gravimetry), also contribute to the ambiguous interpretation of the results of geophysical studies and a small number of deep wells, which also do not add the necessary critical mass to understand the entire geodynamic evolutionary path that its deep subsoil has gone through.

When analyzing the main concepts currently existing, it was found that the processes of eclogitization of the earth's crust and rifting were noted as the leading factors responsible for the formation of the Caspian structure. As a result, the failure of the processes of the first group and the second (with a wide manifestation of the processes of formation of the oceanic type of crust) was revealed, the concepts were also cut off by the time criterion, i.e. considering the formation of the structure in the post-Cambrian time.

Despite the plurality of opinions and the lack of a common opinion on the nature of the Pre-Caspian depression foundation, caused by the above reasons, the authors attempted to revise existing views based on information received in recent years. A critical analysis of the available materials and published literature on this topic was carried out, which makes it possible to speak more constructively about the possible evolution of the geostructure.

There are three stages in the formation of the Pre-Caspian: subduction-collisional (Early Proterozoic), aulacogenous (Late Proterozoic), thermal-relaxation associated with plume subsidence, cooling and formation of the structure of the basin (Early Paleozoic).

References

1. Antipov M.P., Bykadorov V.A., Volozh Yu.A., Leonov Yu.G., Problems of origin and evolution of Pre-Caspian depression (In Russ.), Geologiya nefti i gaza, 2009, no. 3, pp. 11–19.

2. Leonov Yu.G., Volozh Yu.A., Antipov M.P., Consolidate crust of Caspian region (In Russ.), Trudy Geologicheskogo instituta = Transactions of the Geological Institute, 2010, V. 593, 64 p.

3. Artyushkov E.V., Belyaev I.V., Kazanin G.S. et al., Formation mechanisms of ultradeep sedimentary basins: the North Barents basin. Petroleum potential implications (In Russ.), Geologiya i geofizika = Russian Geology and Geophysics, 2014, V. 55, no. 5–6, pp. 821–846, DOI:10.15372/GiG20140508

4. Dobretsov N.L., Polyanskiy O.P., On formation mechanisms of deep sedimentary basins: Is there enough evidence for eclogitization? (In Russ.), Geologiya i geofizika, 2010, V. 51, no. 12, pp. 1687–1696.

5. Volozh Yu.A., Nekrasov G.E., Antipov M.P. et al., Novyy vzglyad na formirovanie konsolidirovannoy kory Prikaspiyskoy neftegazonosnoy provintsii (A new look at the formation of the consolidated crust of the Caspian oil and gas province), In: Tektonika i geodinamika Zemnoy kory i mantii: fundamental’nye problemy-2022 (Tectonics and geodynamics of the Earth’s crust and mantle: fundamental problems-2022), Materials of the LIII Tectonic Meeting, Moscow: GEOS Publ., 2022, pp. 114–119.

6. Druzhinin V.S., Nachapkin N.I., Osipov V.Yu., To problem of tectonic zoning of crystalline crust of Pre-Caspian depression and environmental structures (Existing representations of depth structure and zoning) (In Russ.), Ural’skiy geofizicheskiy vestnik, 2019, no. 2, pp. 37-45, DOI: 10.25698/UGV.2019.2.4.37

7. Druzhinin V.S., Nachapkin N.I., Osipov V.Yu., Seismic-geo-density modeling - The basis for tectonic zoning of the crystalline crust Pre-Caspian depression and environmental structures (In Russ.), Ural’skiy geofizicheskiy vestnik, 2019, no. 4, pp. 21–34, DOI: 10.25698/UGV.2019.4.4.21

8. Kaz’min V.G., Bush V.A., Tikhonova N.F., Passivnaya okraina rifeyskogo okeana na yugo-vostoke Vostochno-Evropeyskoy plity: varianty rekonstruktsiy (Passive margin of the Riphean ocean in the southeast of the East European Plate: Reconstruction options), Proceedings of XVIII International Scientific Conference (School) on Marine Geology, 2009, pp. 233–235.

9. Krylov N.A., Avrov V.P., Golubeva Z.V., Geological model of sub-sart complex at Pre-Caspian depression and its oil and gas content (In Russ.), Geologiya nefti i gaza, 1994, V. 6, p. 32.

10. Orovetskiy Yu.P., On the problem of the genetic foundation of the ancient East European platform (In Russ.), Geofizicheskiy zhurnal, 2010, no. 3, pp. 106–111.

11. Tsvetkova T.A., Shumlyanskaya L.A., Bugaenko I.V., Zaets L.N., Seismotomography of the East-European and Barents-Pechora platforms: three-dimensional P-velocity model of the mantle under Volgo-Uralian, the Pre-Caspian depression and the Barents-Pechora platform (In Russ.), Geofizicheskiy zhurnal, 2010, no. 5, pp. 35-50.

12. Tsvetkova T.A., Bugaenko I.V., Zaets L.N., The main geodynamic border and seismic visualization of plumes under the East European platform (In Russ.), Geofizicheskiy zhurnal, 2019, no. 1, pp. 135-152, DOI: 10.24028/gzh.0203-3100.v41i1.2019.158868

13. Abilkhasimov Kh.B., Tectonic structure of the basement of the Caspian depression (In Russ.), Geologiya i okhrana nedr, 2012, no. 4, pp. 30–39.

14. Miletenko N.V., Fedorenko O.A., Atlas litologo-paleogeograficheskikh, strukturnykh, palinspasticheskikh i geoekologicheskikh kart Tsentral’noy Evrazii (Atlas of lithological-paleogeographic, structural, palinspastic and geoecological maps of Central Eurasia), Almaty: Publ. of Research Institute of Natural Resources YuGGEO, 2002, 26 p.

The article considers the results of 2D and 3D basin modeling of the pre-salt depositions in Kazakhstan's part of the Pre-Caspian basin. The initial data on the heat flow and geochemical parameters (total organic carbon content, hydrogen index, thickness and kinetic schemes of kerogen destruction) of the main source rocks are presented.

The performed work represents the influence of the salt diapirs on the temperature distribution in the sediments of the Pre-Caspian basin, expressed in uneven cooling of the pre-salt interval. Main hydrocarbon migration pathways and the large oil and gas accumulation zones were determined according to the results of 2D modeling. The main «kitchen» areas, level of the source rock organic matter catagenesis were determined due to the 3D modeling. As a part of the work, it was estimated which one of the source rocks contributes more to the total hydrocarbon potential of the region. The heterogeneity of the gaseous and liquid fluid saturation of the different flanks of the Pre-Caspian basin was reproduced. According to the work results, Visean-Bashkirian and Upper Devonian reservoirs contain more than 70% of all accumulated hydrocarbons predominantly one the flanks of the Pre-Caspian basin. Also, as part of the work the fluid composition and its variation vertically across the reef buildups were analyzed. In the article the prospects of the clastic intervals of Upper Carboniferous and Lower Permian alluvial fans were evaluated. The particular features of these potential reservoirs are the following: large occurrence depth, undetermined distribution and uncertain petrophysical parameters. The obtained results can be used for determination of the local prospect areas for future more detailed studies.

References

1. Mansouri Far Siamak, Zui V.I., Geothermal field and geology of the Caspian Sea region (In Russ.), Zhurnal Belorusskogo gos. universiteta. Geografiya. Geologiya = Journal of the Belarusian State University. Geography and Geology, 2019, no. 1, pp. 104 –118, DOI: https://doi.org/10.33581/2521-6740-2019-1-104-118

2. Artemieva I.M., Mooney W.D., Thermal thickness and evolution of Precambrian lithosphere: A global study, Journal of geophysical research, 2001, V. 106, pp. 16387-16414, DOI: https://doi.org/10.1029/2000JB900439

3. Behar F., Vandenbroucke M., Tang Y. et al., Thermal cracking of kerogen in open and closed systems: Determination of kinetic parameters and stoichiometric coefficients for oil and gas generation, Organic Geochemistry, 1997, V. 26, no. 5–6, pp. 321–339, DOI: https://doi.org/10.1016/S0146-6380(97)00014-4

4. Vandenbroucke M., Behar F., Rudkiewicz J.L., Kinetic modelling of petroleum formation and cracking: Implications from the high pressure/high temperature Elgin Field (UK, North Sea), Organic Geochemistry, 1999, V. 30, no. 9, pp. 1105–1125, DOI: https://doi.org/10.1016/S0146-6380(99)00089-3

5. Daukeev S.Zh. et al., Glubinnoe stroenie i mineral'nye resursy Kazakhstana (Deep structure and mineral resources of Kazakhstan), Collected papers “Neft' i gaz” (Oil and gas), Part III, Almaty, 2002, 248 p.

The Pre-Caspian basin has a high oil and gas potential. The sedimentary cover is divided into three complexes – suprasalt, salt and subsalt. The most studied to date is the suprasalt complex. It has the largest number of industrial hydrocarbon accumulations.

The Pre-Caspian basin has been studied unevenly in area and in section. The central part is the least studied because of the thick sedimentary cover, which reaches more than 20 km. However, there are positive prerequisites for the discovery of new oil and gas fields in the subsalt complex.

Basin modeling and modeling of hydrocarbon systems are used nowadays to establish oil and gas potential. When using these methods, maps of the distribution of total organic content (TOC), hydrogen index (HI) and kerogen type over the studied region are the basis for determining the foci of hydrocarbon generation and a necessary element of any basin model. For their construction, the generation characteristics of the oil-producing strata are needed. For these purposes, the authors additionally investigated the core using the Rock-Eval method, selected from wells Embinskaya 9, Kozhasai PGS 1, Vostochny Akzhar 5, Karakulkeldy P 21. But geochemical parameters directly of the well core are always insufficient, they are distributed unevenly over the area and section, which significantly reduces the reliability and detail of the constructions.

Thus, the lack of analytical data on rocks in most of the territory does not allow us to single out oil and gas-producing rocks by area, however, according to the analysis of the physico-chemical properties and composition of oil, biomarkers for the fields of the Tengiz-Karaton zone and the South Embinsky uplift, the approximate age of the oil-producing strata is Devon-middle carbon, it gives reason to assume their wide distribution and good generation potential.

Based on the analysis of published data and conducted studies, four oil-producing strata were identified as the Middle Devonian, Upper Devonian, Lower Carboniferous and Lower Permian, maps of the distribution of Total organic carbon, hydrogen index and kerogen type were constructed for subsequent modeling of hydrocarbon systems.

References

1. Iskaziev K.O., Strategiya osvoeniya resursov nefti i gaza v podsolevykh otlozheniyakh severa Prikaspiyskoy sineklizy (Strategy for the development of oil and gas resources in the subsalt deposits of the northern Caspian syneclise): thesis of doctor of geological and mineralogical science, Moscow, 2021.

2. Iskaziev K.O., Khafizov S.F., Lyapunov Yu.V. et al., Pozdnepaleozoyskie organogennye postroyki Kazakhstanskogo segmenta Prikaspiyskoy vpadiny (Late Paleozoic organogenic structures of the Kazakhstan segment of the Caspian basin), Moscow: URSS, 2019, 250 p.

3. Miletenko N.V., Fedorenko O.A., Atlas litologo-paleogeograficheskikh, strukturnykh, palinspasticheskikh i geoekologicheskikh kart Tsentral’noy Evrazii (Atlas of lithological-paleogeographic, structural, palinspastic and geoecological maps of Central Eurasia), Almaty: Publ. of Research Institute of Natural Resources YuGGEO, 2002.

4. Akhmetshina L.Z. et al., Atlas paleontologicheskikh ostatkov permskikh otlozheniy severnogo i vostochnogo pribortovykh segmentov Prikaspiyskoy vpadiny (Kazakhstanskaya chast’) (Atlas of paleontological remains of Permian deposits of the northern and eastern marginal segments of the Pre-Caspian depression (Kazakhstan part)), Aktobe, 2013, 242 p.

5. Akhmetshina L.Z. et al., Atlas paleontologicheskikh ostatkov, mikrofatsiy i obstanovok osadkonakopleniya famensko-kamennougol’nykh otlozheniy Prikaspiyskoy vpadiny (Kazakhstanskaya chast’) (Atlas of paleontological remains, microfacies and sedimentation environments of the Famennian-Carboniferous deposits of the Caspian depression (Kazakhstan part)), Almaty, 2007, 476 p.

6. Zhemchugova V.A., Prakticheskoe primenenie rezervuarnoy sedimentologii pri modelirovanii uglevodorodnykh sistem (The practical application of reservoir sedimentology in the modeling of hydrocarbon systems), Moscow: Publ. of Gubkin University, 2014, 344 p.

7. Zhemchugova V.A., Myatchin O.M., Devonian reservoirs of oil and gas: Depositional environments, structure features, oil-and-gas bearing capacity (In Russ.), Vestnik Moskovskogo Universiteta. Ser. 4. Geologiya = Moscow University Geology Bulletin, 2015, no. 6, pp. 35–43.

The article presents the lithological and geochemical characteristics of potential oil source rocks on the example of one of the wells on the eastern side of the Caspian depression. According to the complex of geological and geophysical data, several large strata were identified, lithotypes enriched in organic matter (OM) were selected based on core and pyrolytic data. Structural-textural and mineral-material features of rocks largely determine the nature of organic matter distribution. The authors presented a detailed lithological description of various lithotypes, determined the amount and patterns of distribution of organic matter, maturity level and, as a result, the oil source potential of a particular rock. The article introduces a detailed lithological description of the section of one of the deep wells of the pre-salt complex of the Upper Paleozoic. Due to a detailed study of the core material, characteristics that allowed making an assumption about attributing of certain strata to potential oil source intervals were determined.

The study of rocks was conducted by optical microscopy with the identification and description of lithotypes, with special attention paid to the nature of the distribution of organic matter in the rock. The Rock-Eval method was used to determine the generation potential of the rocks. The article presents data on the main geochemical parameters - the total organic carbon in the rock, the hydrogen index and the temperature corresponding to the maximum yield of hydrocarbons in the S2 peak (the residual generation potential of the rock). As a result, the classes of oil source rocks, the type of kerogen and the stage of maturity of organic matter were measured.

The results can be correlated with the intervals of occurrence of rocks of similar lithotypes in the similar strata in the wells section that were not characterized by a core.

References

1. Antipov M.P., Bykadorov V.A., Volozh Yu.A. et al., Osobennosti stroeniya Priural’skoy kraevoy sistemy Vostochno-Evropeyskogo kontinenta v svyazi s neftegazonosnost’yu (Features of the structure of the Urals regional system of the East European continent in connection with the oil and gas potential), In: Neftegazonosnye basseyny Kazakhstana i perspektivy ikh osvoeniya (Oil and gas bearing basins of Kazakhstan and prospects for their development), Almaty: KONG Publ., 2015, pp. 264–280.

2. Abilkhasimov Kh.B., Characteristics of oil and gas accumulation zones and features of the location of natural reservoirs in the Paleozoic complex of the Caspian depression (In Russ.), Geologiya i okhrana nedr, 2011, no. 3(40), pp. 35–47.

3. Miletenko N.V., Fedorenko O.A., Atlas litologo-paleogeograficheskikh, strukturnykh, palinspaticheskikh i geoekologicheskikh kart Tsentral’noy Evrazii (Atlas of lithological-paleogeographic, structural, palinspatic and geoecological maps of Central Eurasia), Almaty: Publ. of YuGGEO, 2002.

4. Savel’eva O.L., Savel’ev D.P., Chubarov V.M., Pyrite framboids in carbonaceous rocks of Smaginassotiation in the Kamchatsky Mys peninsula (In Russ.), Vestnik kamchatskoy regional’noy organizatsii Uchebno-nauchnyy tsentr. Ser. Nauki o Zemle, 2013, no. 2(22), pp. 144–151.

5. Postnikov A.V., Musikhin A.D., Osintseva N.A. et al., Influence of rocks pore structure on deposits development of Khadum formation in East Caucasian region (In Russ.), Geofizika, 2016, no. 6, pp. 30–38.

6. Iskaziev K.O., Savinova L.A., Almazov D.O., Lyapunov Yu.V., Prospects of oil and gas potential of deep-water Lower Permian deposits within the eastern part of the Pre-Caspian basin (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2021, no. 5, pp. 22–25, DOI: https://doi.org/10.24887/0028-2448-2021-5-22-25

The article is about formation conditions and the main patterns of distribution of potential reservoir rocks of the pre-salt complex of the Upper Paleozoic of the eastern and southeastern parts of the Caspian depression. The studies were based on a complex of geological and geophysical data, including seismic data, borehole geophysics, core data, as well as on literature data, using examples of already studied deposits close in genesis to those under study. The lithofacies environment of the formation of both carbonate and terrigenous complexes are considered. Structural, textural, material features and a set of lithotypes of the carbonate natural reservoirs make it possible to use J. Wilson sedimentation model with the identification of most favorable zones for the formation of the reservoir potential. According to this, the formation of the carbonate complex took place in relatively shallow waters with different hydrodynamics. The boundstones of the facies zone of organogenic structures and the grainstones of the upper slope are characterized with the highest porosity coefficient. Moreover, an obligatory condition for the presence of reservoir rocks with improved characteristics is the confinement of deposits to hypergenesis zones.

The formation of the terrigenous complex took place during and under the conditions of the growing mountain structure of the Urals, when the marginal trench was filled with clastic material carried from the orogen. Such deposits are characterized by a rhythmic structure and a gradation distribution of fragments within rhythms. In such rhythms, potential reservoirs will be confined to the bases of the rhythms, for example sandstones have the highest porosity in the studied wells. However, deposits of this genesis will be characterized by high vertical anisotropy due to the relatively thin alternation of rocks. Nowadays, the carbonate complex where large deposits of oil and gas have already been discovered in is the most studied. The terrigenous pre-salt complex of the Caspian depression has been poorly studied, however, the oil and gas potential of deposits of a similar genesis has already been proven in the Permian deposits of the United States.

References

1. Iskaziev K.O., Khafizov S.F., Lyapunov Yu.V. et al., Pozdnepaleozoyskie organogennye postroyki Kazakhstanskogo segmenta Prikaspiyskoy vpadiny (Late Paleozoic organogenic structures of the Kazakhstan segment of the Caspian basin), Moscow: URSS, 2019, 250 p.

2. Dunham R.J., Classification of carbonate rocks according to depositional textures, In: Classification of carbonate rocks, Tulsa, Oklahoma, American Association of Petroleum Geologists, 1962.

3. Wilson J.L., Carbonate facies in geologic history, Springer-Verlag, Berlin, 1975, 463 p.

4. Handford C.R., Loucks R.G., Carbonate depositional sequences and systems tracts-responses of carbonate platforms to relative sea-level changes, Chapter 1, 1993.

5. Lucia F.J., Carbonate reservoir characterization: An integrated approach, Springer, Berlin Heidelberg New York, 2007, 333 p.

6. Iskaziev K.O., Khafizov S.F., Kratkiy obzor turbiditnykh kompleksov permskogo megabasseyna (Tekhas i N’yu-Mekhiko, SShA) (Brief review of turbidite complexes of the Permian megabasin (Texas and New Mexico, USA)), Moscow-Izhevsk: Publ. of Institute for Computer Research, 2020, 192 p.

7. Gorozhanin V.M., Gorozhanina E.N., The Lower Permian in “Toratau” Geopark: rhythmically layered depressional and flysch deposits of the Preuralian Foredeep (In Russ.), Geologicheskii vestnik, 2019, no. 3, pp. 153–160, DOI: http://doi.org/10.31084/2619-0087/2019-3-10

The article presents the result of geological interpretation of the lineaments system of planetary directions in Western Kazakhstan and establishes their connection with oil and gas potential. Brief information about the history of the study of a regular (regmatic) network of lineaments (planetary fracturing, megafracturing) and the objections of opponents to the existence of such a network are given. The importance of studying a regular network of lineaments is due to the fact that they are zones of increased permeability, which, obviously, is important for predicting oil and gas potential and identifying areas for the development of fractured reservoirs. Revealing the characteristics of a regular network makes it possible to predict these zones even in cases where their fragments cannot be deciphered.

The paper discusses objections to the disjunctive nature of lineaments and shows that the non-reproducibility of lineament interpretation schemes and their unreliability can be overcome by following certain rules when conducting geological interpretation. The article discusses the issues of reproducibility of the results of geological interpretation of lineaments on satellite images and provides recommendations for obtaining reproducible results. The methodology and source materials of the work are described, and the results of image interpretation using the LESSA program are presented.

The images were interpreted at two scale levels - 1:10 000 000 and 1:25 000. The territory of Western Kazakhstan was studied using Landsat 5, 7 and 8 images (monochrome and synthesized images were used).

On the images of the Caspian Sea and the Turan Plate at a scale of 1:10 000 000, a system of lineament bundles of planetary directions with regular distances between unidirectional lineaments is established. It has been established that the main oil fields are located at the intersections of the beams of the latitudinal and northeastern directions.

In more detail (on a scale of 1:25,000), the node of the intersection of lineaments of all directions is reviewed, located at the confluence of the rivers Emba and Temir. Lineament bundles of planetary directions are also distinguished here, but with smaller distances between unidirectional bundles. Known deposits - Kenkiyak, Zhanazhol, Ambekmola fall into the nodes of their intersections.

As a result, the geometric characteristics of the network of lineaments and the geometric confinement of large deposits to the nodes of their intersections were revealed.

References

1. Shul’ts S.S., Planetarnaya treshchinovatost’ (Planetary fracturing), Leningrad: Publ. of LSU, 1973, pp. 5–37.

2. Bush V.A., Analiz kosmogeologicheskoy karty SSSR (Analysis of the cosmogeological map of the USSR), In: Kosmogeologiya SSSR (Cosmogeology of the USSR): edited by Bryukhanov V.N., Mezhelovskiy N.V., Moscow: Nedra Publ., 1987.

3. Sadovskiy M.A., On the block structure of the Earth’s lithosphere (In Russ.), Uspekhi fizicheskikh nauk, 1985, V. 147, pp. 421–422.

4. Lopatin D.V., Geomorphologic indication of deep ore-bearing structural forms (In Russ.), Vestnik Moskovskogo Universiteta. Seria 5, Geografia = Moscow University Bulletin. Series 5, Geography, 2011, no. 1, pp. 28–35.

5. Lopatin D.V., Lineament tectonics and giant deposits (In Russ.), Issledovanie Zemli iz kosmosa, 2002, no. 2, pp. 77–90.

6. Belozerov V.B., Planar fracturing and development of petroleum reservoirs (In Russ.), Izvestiya Tomskogo politekhnicheskogo universiteta = Bulletin of the Tomsk Polytechnic University. Geo Assets Engineering, 2015, V. 326, no. 1, pp. 6–13.

7. Koronovskiy N.V., Bryantseva G.V., Goncharov M.A. et al., Lineaments, planetary jointing, and the regmatic system: main points of the phenomena and terminology (In Russ.), Geotektonika = Geotectonics, 2014, no. 2, pp. 75–88.

8. Miloserdova L.V., Dependence of parameters of megafractures on the scale of deciphered images (In Russ.), Izvestiya vuzov. Geologiya i razvedka, 1982, no. 3, pp. 156–158.

9. Miloserdova L.V., On the influence of the scale factor on the predominant orientation of a megafracture (In Russ.), Vestnik MGU im. M.V. Lomonosova. Seriya 4. Geologiya = Moscow University Geology Bulletin, 1982, no. 4, pp. 99–103.

The textural characteristics of the anomalous gravitational and magnetic fields of the Pre-Caspian syneclise are studied using the WinLESSA software package. The results are compared with the lineament network deciphered from space images in the visible and infrared zones of the spectrum. It has been established that the WinLESSA software is applicable for revealing textural features of geophysical fields.
It has been established that changes in the texture of geophysical fields have distinct patterns. The anisotropy of the magnetic field is oriented in the northwest direction. The texture of the gravitational field has sublatitudinal, northeastern and northwestern directions. Lineament bundles identified by anomalous fields have a quasi-periodic character and planetary orientation (rays of orthogonal and two diagonal directions), which indicates their connection with planetary stress systems. The largest lineaments are reproduced on all materials, but their density (abundance) depends on the settings adopted and the details of the original image. The textural characteristics of the anomalous gravitational and magnetic fields of the Pre-Caspian syneclise and the results of lineament interpretation are compared with the results of known fault maps. In the north of the Pre-Caspian syneclise, additional blocks have been identified by other methods according to magnetic survey data.
Conclusions are presented about the main characteristics of lineaments identified from satellite images, maps of magnetic and gravitational anomalies. The lineaments are generally comparable, with regard to clusters of rose diagrams, and elongation vectors, for which it is impossible to either find correspondences in the previously identified faults, or identify any patterns  a chaotic distribution was revealed, the maxima and minima are also randomly and irregularly located on the density map strokes.

References
1. Volozh Yu.A., Antipov M.P., Garagash I.A., Lobkovskiy L.I., Eklogitovaya model' formirovaniya Prikaspiyskoy vpadiny (Eclogitic model of the formation of the Pre-Caspian Basin), In: Osadochnye basseyny: metodika izucheniya, stroenie i evolyutsiya (Sedimentary basins: a technique of studying, a structure and evolution): edited by Leonov Yu.G., Volozh Yu.A., Moscow: Nauchnyy mir Publ., 2004, pp. 471-486.
2.  Leonov Yu.G., Volozh Yu.A., Antipov M.P., Konsolidirovannaya kora Kaspiyskogo regiona: opyt rayonirovaniya (Consolidated crust of the Caspian region: zoning experience): edited by Leonov Yu.G., Moscow: GEOS Publ., 2010, 64 p.
3. Karta razlomov territorii SSSR i sopredel’nykh stran (Fault map of the territory of the USSR and neighboring countries): edited by Belyaevskiy N.A., Unksov V.A., Moscow: Publ. of Aerogeologiya, 1980.
4.  Miloserdova L.V., Aerokosmicheskie metody v neftegazovoy geologii (Aerospace methods in petroleum geology): edited by Florenskiy P.V., Moscow: Nedra Publ., 2022, 502 p
5. Zlatopol’skiy A.A., Automation of lineament analysis - LESSA methodology. Extended lineaments. Methodological review (In Russ.), Dinamicheskaya geologiya, 2020, no. 1, pp. 55-66.

Lineaments, as visual objects that stand out on space images and reflect zones of reduced rock strength in the landscape, as well as the boundaries of tectonic blocks, have not yet been exhaustively studied despite many years of research. To identify and geometrize the zones of fractured reservoirs development in the pre-Mesozoic section, it is necessary to determine the areas of lineaments concentration. The study of lineaments is facilitated by the development of computer technologies for detecting and processing linear image elements. To decipher the lineaments, a mosaic of space images received from the Landsat-7 satellite was used. The "density of strokes" function in the LESSA program is used. Based on the deciphered lineaments, the program identified generalized extended lineaments.

Therefore, in order to allocate promising zones of fractured reservoirs development in the general system of the fracture field, it is necessary to map the zones of their maximum concentration

Zones of maximum concentration of fractured reservoirs have been identified, which are confined to inherited developing planetary systems, laid down in the period of lithification. On diagrams built using the LESSA program, they look like bundles of unidirectional lineaments.

Lineament thickening zones can be considered as promising objects for the development of fractured reservoirs and unconventional hydrocarbon deposits. Large zones of development of fractured reservoirs have been mapped. 101 objects have been identified that require more detailed research. In the central part of the study area, single, small-sized objects were identified. Most of the identified objects are confined to the west of the territory in the area of Zhangalinsky and Bokeyorda districts. The sizes of zones of development of fractured reservoirs do not exceed 1012 km. The identified zones of lineament thickening (nodes) can be considered as possible territories for the development of fractured reservoirs and, accordingly, the localization of unconventional hydrocarbon deposits.

References

1. Amurskiy G.I., Distantsionnye metody izucheniya tektonicheskoy treshchinovatosti porod neftegazonosnykh territoriy (Remote sensing methods for studying tectonic fracturing of rocks in oil and gas areas), Moscow: Nedra Publ., 1988, 164 p.

2. Zlatopol’skiy A.A., Automation of lineament analysis - LESSA methodology. Extended lineaments. Methodological review (In Russ.), Dinamicheskaya geologiya, 2020, no. 1, pp. 55-66.

The Pre-Verkhoyansk foredeep is territorially confined to the Republic of Sakha (Yakutia), in tectonic terms it is part of the Siberian Platform, being its eastern frame, its area is 520 thousand km2. According to the oil and gas geological zoning, the study area belongs to the Predverkhoyansk oil and gas region, which is part of the Leno-Vilyui oil and gas province. The trough stretches from the lower reaches of the Lena River to the middle course of the Aldan River. The shape of the deflection resembles an arc.

The geological study of the Pre-Verkhoyansk foredeep territory begins at the end of the 40s and the beginning of the 50s of the last century. In 1951 specialists of the Yakutsk Geological Administration drew up a long-term plan for prospecting and exploration of oil and gas for 19551960. During the implementation of the plan, two deposits were discovered  Ust-Vilyuiskoye (1956) and Sobo-Khainskoye (1961).

Parametric drilling was carried out on the territory of the trough, and seismic surveys were carried out using the common depth point method in the basin of the river Sobolokh-Mayan in the 7080s, however, as a result of these and subsequent exploration, no commercial accumulations of hydrocarbons were discovered.

Thus, the high prospects for the oil and gas potential of the Predverkhoyansk foredeep have not been proven at present.

the author carried out 3D basin modeling on the basis of published data on the territory of the Republic of Sakha (Yakutia) within the Lena branch of the Predverkhoyansk trough. Qualitative and quantitative criteria are analyzed and described for the prospects for oil and gas in the study area. Recommendations on promising areas of exploration work are presented.

Schlumberger PetroMod software was used for basin modeling. Based on the results of the performed 3D modeling, the following oil and gas conditions were analyzed  paleostructural, lithofacies and geochemical conditions. The catagenetic evolution, the degree of depletion of the generation potential of oil and gas source rocks are also considered, the processes of migration and accumulation of hydrocarbons are evaluated.

References

1. Frolov S.V., Karnyushina E.E., Korobova N.I. et al., Features of the structure, sedimentary complexes and hydrocarbon systems of the Leno-Vilyui oil and gas basin (In Russ.), Georesursy, 2019, V. 21, no. 2, pp. 13-30, DOI: 10.18599/grs.2019.2.13-30

2. Astakhov S.M., Georeaktor. Algoritmy neftegazoobrazovaniya (Georeactor. Algorithms for oil and gas generation), Rostov-on-Don: Kontiki Publ., 2015, 256 p.

3. Maslennikov M.A., Sukhov S.S., Sobolev P.N. et al., Cambrian barrier reef systems of Siberian Platform: petroleum potential in light of new geological and geophysical data (In Russ.), Geologiya nefti i gaza, 2021, no. 4, pp. 29–50, DOI: 10.31087/0016-7894-2021-4-29-50

4. Parfenova T.M., Kashirtsev V.A., Korovnikov I.V., New naphthide shows finds in the Middle Cambrian rocks in the north-eastern Siberian platform (In Russ.), Neftegazovaya geologiya. Teoriya i praktika, 2014, no. 2(9).

5. Sobolev P.N., Smirnov E.V., Sagimbaev E.T., Perspektivy poiskov slantsevoy nefti v inikanskoy i kuonamskoy formatsiyakh na territorii Vostochnoy Sibiri (Prospects for prospecting for shale oil in the Inikan and Kuonam formations in Eastern Siberia), 2017, URL: https://spmi.ru/sites/default/files/imci_images/sciens/document/2017/Smirnov.pdf

6. Bazhenov T.K., Dakhnova M.V., Zheglova T.P. et al., Neftematerinskie formatsii, nefti i gaza dokembriya i nizhnego-srednego kembriya Sibirskoy platformy (Oil source formations, oil and gas of the Precambrian and Lower-Middle Cambrian of the Siberian Platform), Moscow: Publ. of VNIGNI, 2014, 128 p.

7. URL: http://heatflow.org/thermoglobe/worldmap/

In recent years, the geological structure has become more complex, the number of new discovered hydrocarbon deposits is decreasing. Thus, in order to maintain and replenish the resource base, modern research methods are needed to reproduce the geological structure in detail of deep-lying horizons.

This article discusses a modern approach to the detailed study and modeling of alluvial polyphase systems of paleochannels in order to search for promising objects for geological exploration. As an example, the process of studying one of the formations of the Tyumen suite in the West Siberian oil and gas province is described.

The approach used includes a full range of studies, starting with the study of the results of 3D seismic interpretation  the most widely used method in the analysis of alluvial continental deposits is the spectral decomposition method, which allows geometrizing cut bodies and conducting seismic facies zoning. After the analysis of seismic surveys, special attention was paid to the downhole analysis and correlation of the selected objects with the result of geophysical studies of wells. Thus, after a detailed analysis of the seismic interpretation results along with well information, a final conceptual model was obtained, which, in turn, can be used as a basis for further 2D or 3D geological modeling. While modeling it is necessary to take into account the significant heterogeneity and uncertainty of the geological structure of such systems. Even the most modern methods of conducting and interpreting seismic surveys cannot yet give a clear zoning of the distribution of reservoirs within such deposits. Therefore, for the construction of a geological model and the subsequent assessment of the resource base, probabilistic modeling should be used, establishing ranges of variable parameters. Thus, in conditions of sufficiently large uncertainties, it will be possible to obtain a probabilistic picture of promising objects for further exploration

References

1. 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.

2. Muromtsev V.S., Elektrometricheskaya geologiya peschanykh tel – litologicheskikh lovushek nefti i gaza (Electrometric geology of sand bodies - lithological traps of oil and gas), Leningrad: Nedra Publ., 1984, 260 p.

3. Baraboshkin E.Yu., Prakticheskaya sedimentologiya. Terrigennye rezervuary. Posobie po rabote s kernom (Practical sedimentology. Terrigenous reservoirs. On how to operate core samples), Tver: GERS Publ., 2011, 152 p.

4. Belozerov V.B., Role of sedimentation models in electrofacial analysis of terrigenous deposits (In Russ.), Izvestiya Tomskogo politekhnicheskogo universiteta = Bulletin of the Tomsk Polytechnic University, 2011, V. 319, no. 1, pp. 116-123.

One of the key initiatives proclaimed in the Strategy Rosneft – 2030 is to develop Operational Efficiency Improvement (OEI) System overall through the Company and particularly, in Upstream block. Company makes significant efforts to reduce operational and capital expenditures through implementing best technical and process management practices as well as upscaling modern innovation technologies successfully tested in the oil industry. All producing subsidiaries take active part in this process. OEI System targets gradual movement from the set of several optimization projects to concrete defined operational solutions / technical instruments that will determine cost reduction and allow achievement of maximum effects through implementation of operational efficiency improvement projects. OEI System covers all main operational domains related to hydrocarbons production on land in Russian Federation. The article presents practical examples of operational efficiency improvement projects in domain power generation in oil and gas production. Particular attention is paid to experience exchange between producing subsidiaries and scaling up of successful projects across the Company. Special tool («upscale hive») is used to monitor this process. Certain targets are annually set for producing subsidiaries to reach planned effects from project being implemented and to cover unallocated potential of operational efficiency improvement by means of new projects. Those effects are included in business-plans of producing subsidiaries.

References

1. Isakov A.S., Lunin D.A., Khoroshev A.N., Integral rating of subsidiaries of Rosneft Oil Company (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2020, no. 11, pp. 16–19, DOI: https://doi.org/10.24887/0028-2448-2020-11-16-19

2. Isakov A.S., Liron E.M., Lunin D.A., Khoroshev A.N., Development of oilfield services market: successful practice of Rosneft Oil Company (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 11, pp. 8–12, DOI: https://doi.org/10.24887/0028-2448-2019-11-8-12

3. Isakov A.S., Liron E.M., Contractor effective performance management system (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 3, pp. 18–21,

DOI: https://doi.org/10.24887/0028-2448-2019-3-18-21

4. Isakov A.S., Liron E.M., Rozenberger E.B., Khoroshev A.N., Analytical review of the oilfield service market in Rosneft Oil Company PJSC (well remedial and workover) (In Russ.), Gazovaya promyshlennost', 2021, no. 7, pp. 94–109.

5. Isakov A.S., Liron E.M., Matveev S.N., Khoroshev A.N., Analytical review of the oilfield service market in Rosneft Oil Company PJSC (hydraulic fracturing) (In Russ.), Gazovaya promyshlennost', 2021, no. 8, pp. 62–71.

6. Isakov A.S., Liron E.M., M Basyrov.A., Khoroshev A.N., Analytical review of the oilfield service market in Rosneft Oil Company PJSC (perforating and blasting) (In Russ.), Gazovaya promyshlennost', 2021, no. 9, pp. 44–52.

7. Kholopova L., Perfection non-stop (In Russ.), Sibirskaya neft', 2018, V. 156, no. 9, pp. 22-25, URL: https://www.gazprom-neft.ru/files/journal/SN156.pdf

8. Samoylenko V., Business models of oilfield services and the efficiency of oil companies (In Russ.), Ekonomika i upravlenie: nauchno-prakticheskiy zhurnal, 2016, no. 4 (132), pp. 87-93.

The conceptual geological model is the author's idea of the object under consideration from the standpoint of sedimentation conditions, the formation of reservoir properties and the spatial distribution of productive intervals, which is based on accumulated experience and the entire amount of factual data. The work performed is aimed at studying one of the largest assets of PJSC NK Rosneft, located in Eastern Siberia. The object of study in the presented work was the Vendian complex in the interval of the Vanavara and Oskoba formations, represented by terrigenous, carbonate and terrigenous-sulphate-carbonate deposits. For reliable mapping of productive formations in conditions of a complex heterogeneous geological structure, due to frequent changes in lithological composition and wedging out of formations, it is necessary to have a comprehensive understanding of the object. The methodological approach of RN-KrasnoyarskNIPIneft LLC described in the article includes the principles of detailed correlation and a set of analyzes aimed at studying the properties of reservoir rocks and their spatial distribution based on the data of laboratory studies of core material, standard and special methods of well logging and CDP-3D seismic surveys. As a result of the work, correlated lithostratigraphic units were identified, their qualitative and quantitative characteristics were given, the patterns of their distribution over the area were determined, and the mining potential was estimated. An integrated approach and consistent analysis made it possible to obtain a reliable three-dimensional geological model that can be used to predict the development of zones with improved porosity and porosity properties, plan exploration and production drilling, and assess the resource potential.

References

1. Kozyaev A.A., Bibik A.N., Kvachko S.K. et al., Spektral’naya dekompozitsiya – effektivnaya metodika dlya izucheniya geologicheskikh osobennostey, na primere mestorozhdeniy Vostochnoy Sibiri (Spectral decomposition is an effective technique for studying geological features, on the example of fields in Eastern Siberia), Proceedings of Geomodel 2016 – 18th Science and Applied Research Conference on Oil and Gas Geological Exploration and Development, 2016, DOI: 10.3997/2214-4609.201602210

2. Mel’nikov N.V., Yakshin M.S., Shishkin B.B. et al., Stratigrafiya neftegazonosnykh basseynov Sibiri. Rifey i vend Sibirskoy platformy i ee skladchatogo obramleniya (Stratigraphy of oil and gas bearing basins of Siberia. Riphean and Vendian of the Siberian platform and its folded frame), Novosibirsk: Geo Publ., 2005, 428 p.

3. Kochnev B.B., Sedimentation settings of the Vendian Vanavara formation, the Siberian Platform (In Russ.), Stratigrafiya. Geologicheskaya korrelyatsiya, 2008, V. 16, no. 1, pp. 22-33, DOI: 10.1007/s11506-008-1002-2

The article considers the problem of determining the economically optimal number of wells for oil and gas fields under production constraints without optimization of oil recovery rate. Similar problems may arise if there is a point of sale of products in the immediate vicinity of the field, as well as in some other cases. The technical and economic model of the process is based on an exponential model of potential well production decline, adjusted for the presence of infrastructural restrictions on production. The analysis of the model showed the possibility of reducing the dimension of the problem to two dimensionless variables - the dimensionless cost of well construction and the dimensionless recovery rate. In this case, the optimal number of wells is described by the dimensionless value of the filling factor of a constant production rate. The optimization problem was solved for a wide range of control parameters, the pessimistic boundaries of which are determined by the development profitability, the optimistic ones – by the maximum indicators for the industry. The solution is presented in graphical form and in the form of an analytical expression for the correlation of the optimal number of wells versus the dimensionless well construction cost and dimensionless recovery rate. It is shown that the presence of restrictions on the rate of extraction reduces the sensitivity of the optimal number of wells to variations in productivity, the cost of well construction and net-back oil prices compared to the optimal values in the absence of restrictions on the recovery rate. In addition, the deterioration of technical and economic conditions - a decrease in productivity and net-back oil prices, an increase in the cost of well construction - leads to a decrease in the optimal number of wells and a reduction in the duration of the period of a constant rate of production. The results of the work can be used when performing analytical assessments of the sensitivity of design solutions for the development of fields remote from the infrastructure of pipeline transport or facilities that support the production levels of large fields.

References

1. Tokunaga H., Hise B.R., A method to determine optimum well spacing, SPE-1673-MS, 1966, DOI: https://doi.org/10.2118/1673-MS

2. Khasanov M.M., Ushmaev O., Nekhaev S., Karamutdinova D., The optimal parameters for oil field development (In Russ.), SPE-162089-MS, 2012,

DOI: https://doi.org/10.2118/201987-MS

3. Апасов Р.Т., Бадгутдинов Р.Р., Варавва А.И. et al., Estimation of optimal parameters for gas field development system (In Russ.), Нефтяное хозяйство = Oil Industry, 2021, no. 12, pp. 74–78, DOI: https://doi.org/10.24887/0028-2448-2021-12-74-78

4. Arps J.J., Analysis of decline curve, Trans. AIME, 1945, pp. 228-247, DOI:10.2118/945228-G

5. Xiao-Hui Wu, Linfeng B., Kalla S., Effective parametrization for reliable reservoir performance predictions, International Journal for Uncertainty Quantification, 2012, V. 2, no. 3, pp. 259–278, DOI: 10.1615/Int.J.UncertaintyQuantification.2012003765

The main oil fields of the Surgut dome got to final stage of development. The project well fund is practically fully implemented, and oil production levels are maintaining through the use of geological and technical measures. Improving the effectiveness of wellwork planning depends on reliability of determining the structure of current recoverable oil reserves. This problem is solved by performing calculations with using 3D hydrodynamic models. The Tyumen branch of SurgutNIPIneft annually performs a significant number of laboratory studies of residual oil saturation and oil displacement ratio. The experience gained makes it possible to generalize the results of the core studies for various oil reservoirs of the Surgut dome. As a result of the generalization of the primary core studies, the dependence of residual oil saturation on the initial oil saturation and porosity was obtained. The proposed method of substantiating the residual oil saturation was compared with others ones used in the industry. In most cases, the method allows to get a higher convergence with laboratory studies, and therefore a higher reliability of determining the residual oil saturation. The resulting dependence has become widespread, since it takes into account reservoir properties and is characterized by a higher coefficient of determination. This makes it possible to reliably solve the problems of modeling field development, determining the structure of residual reserves and planning successful activities. The proposed approach to substantiate the displacement efficiency can be used along with other well-known dependencies in the preparation of oil field development projects.

References

1. Sonich V.P., Barkov S.L., Pecherkin M.F., Malyshev G.A., Novye dannye izucheniya polnoty vytesneniya nefti vodoy (New data on the study of the completeness of oil displacement by water), Moscow: Publ. of VNIIOENG, 1997, 32 p.

2. Kostyuchenko S.V., Cheremisin N.A., Direct calculation of sweep efficiency and localization of current recoverable oil reserves in digital models (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 7, pp. 94–98, DOI: 10.24887/0028-2448-2019-7-94-98

3. Al’vard A.A., Biglov A.Sh., Salikhov M.R., Estimating the oil displacement coefficient by using statistical models in the conditions of Gazpromneft-Noyabrskneftegas JSC oil fields (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2021, no. 12, pp. 56–59, DOI: 10.24887/0028-2448-2021-12-56-59

4. Yanin A.N., Assessment of coefficient of water-oil displacement as per summarized dependencies (example of Yu1 group’’s strata of Nizhnevartovsky pool roof) (In Russ.), Burenie i neft’, 2014, no. 7-8, pp. 34-38.

To date significant reduce of bituminous oil viscosity is the only way to start its production. Among the most common injected agents is steam, solvent or their combinations. When developing bituminous oil reserves, due to their high viscosity, modern approaches are required, from creation of new solvent compositions to implementation of cost-effective technologies for natural bitumen production. Cyclic steam – solvent stimulations results in residual bituminous oil recovery and increase of bituminous oil displacement efficiency.

The article presents the results of pilot tests of steam and solvent composition injections. The solvent composition was developed at Almetyevsk State Oil Institute during the implementation of the project with federal support in 2017-2020 to increase the efficiency of bituminous oil reserves development in marginal zones of deposits under conditions of high reservoir heterogeneity. Previously laboratory studies ware carried out and solvent composition was developed. During filtration tests this solvent effectively reduced oil viscosity and prevented asphaltene precipitation in the reservoir, resulting in an increase of displacement efficiency. These results were fully confirmed in pilot tests. According to the results of pilot tests injection of developed solvent composition into steam-cycle wells increases oil production rate of steam-cycle wells due to additional oil recovery with the solvent in comparison with pure steam injection. Moreover, it was found that the injected solvent spread laterally through the reservoir and reached neighboring pairs of injection and production wells operating in the steam-gravity drainage mode. As a result due to solvent injection areal sweep efficiency increases and additional oil reserves are involving into development.

References

1. Zakirov I.S., Zaripov A.T., Zakharova E.F. et al., Improving the technology of huff-and-puff well treatment with areal solvent application (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 9, pp. 102–106, DOI: https://doi.org/10.24887/0028-2448-2019-9-102-106

2. Zakirov I.S., Zakharova E.F., Sayakhov V.A., The complex experimental research results on the solvent composition selection for bituminous oil production (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 9, pp. 98–101, DOI: https://doi.org/10.24887/0028-2448-2019-9-98-101

3. Zakirov I.S., Zakharova E.F., Sayakhov V.A., Study of the influence of thermal steam and chemical methods on the hydrocarbon composition of bituminous oil (In Russ.), Neftyanaya provintsiya, 2019, no. 4(20), pp. 261–274, DOI: 10.25689/NP.2019.4.261-274

4. Zakirov I.S., Zakharova E.F., Razumov A.R., Beloshapka I.E., Evaluation of oil sweep efficiency based on the results of laboratory experiments with formation model using heat exposure and solvents (In Russ.), Neftyanaya provintsiya, 2019, no. 2(18), pp. 197–209, DOI: 10.25689/NP.2019.2.197-209

5. Patent RU 2705135 C1, Procedure for complex choice of solvent composition for action on bituminous oil, Inventors: Zakirov I.S., Zakharova E.F., Sayakhov V.A., Shaydullin L.K.

6. Takhautdinov Sh.F., Sabirov R.K., Ibragimov N.G. et al., Sozdanie i promyshlennoe vnedrenie kompleksa tekhnologiy razrabotki mestorozhdeniy sverkhvyazkikh neftey (The creation and implementation of technology complex for heavy oil deposits development), Kazan': Fen Publ., 2011, 142 p.

Acid treatments are the most widely used methods to improve the well performance. Acid pumping is aimed not only on controlling the clogging of the bottomhole area, but also on improving the permeability by dissolving the minerals and creating new filtering channels. Acid treatment technology depends on many factors, including the specific geophysical conditions of the target area and type of applied acids and acid compositions. The important role during the acid treatment designing is given to a correct selection of process liquids. So, optimization of the acid composition to the mineralogy of the reservoir rock is one of the prerequisite for successful acid treatment, since chemical reactions within the reservoir are the key factors for the efficiency of the process. Practically, selection of the required acid composition is performed without the necessary research-methodological justification. So, for example, selection of acid compound for clastic reservoir treatment does not consider the mineralogy of the specific interval leading to a decreased efficiency of such treatments.

The study introduces a complex research-methodological approach to justify the selection of formulary process solutions, considering the specifics of reservoir mineralogy and pressure-temperature conditions. The approach includes the historic analysis of acid treatments results in Vietsovpetro wells, reservoir mineralogy analysis with a justified selection of main compounds for each group, adaptation of base compound formula for the specific geophysical conditions, laboratory and pilot testing. Reservoir mineralogy analysis showed that Vietsovpetro fields’ sandstones are mostly arcosic. Main acid compositions for all applied areas should consider the high content of feldspars with further fine-tuning in terms of permeability, high content of clays, zeolites, chlorites and reservoir temperature value. Basic acid compositions matrix under various permeability values has been developed for the main clastic pay zones of White Tiger, Dragon, White Bear and White Hare fields. Acid compositions formulas have been improved to adapt to the specific geophysical conditions. Main conclusions and recommendations on selecting the acid compositions formulas for the specific geophysical conditions have been verified by the laboratory and pilot testing.

References

1. McLeod H.O., Ledlow L.B., The planning, execution, and evaluation of acid treatments in sandstone formations, SPE-11931-MS, 1983, DOI: https://doi.org/10.2118/11931-MS

2. Economides M.J., Nolte K.G., Reservoir Stimulation, Third Edition, Wiley, Chichester, 2000, 750 p.

3. Kalfayan L.K. Production enhancement with acid stimulation, Tulsa: Oklahoma, 2008, 265 p.

4. Shafiq M.U., Mahmud H.B., Sandstone matrix acidizing knowledge and future development, J Petrol Explor Prod Technol., 2017, V. 7, pp. 1205–1216, DOI: https://doi.org/10.1007/s13202-017-0314-6

5. Merkulov I.P., Geofizicheskie issledovaniya skvazhin (Well logging), Tomsk: Publ. of TPU, 2008, 139 p.

6. Abdelmoneim S.S., Nasr-El-Din H.A., Determining the optimum HF concentration for stimulation of high temperature sandstone formations, SPE- 174203-MS, 2015, DOI: https://doi.org/10.2118/174203-MS

At present, pilot works are being carried out at the fields in Western Siberia to extract oil from the Bazhenov formation. The Bazhenov formation has a complex composition, which contains inorganic substances, as well as organic compounds, such as mobile and sorbed hydrocarbons, kerogen and bitumen. The main inflow was obtained from carbonate-siliceous-clay intervals, the reservoir type is porous-microcavernous and fractured-cavernous. To ensure profitable oil production, wells are put into operation after hydraulic fracturing (HF). However, the dynamics of well production rates is characterized by a high rate of decline, which leads to unprofitable production. An urgent task of developing the Bazhenov formation is to ensure profitable production rates during operation. One of the solutions to this problem is the acid treatment of the bottomhole zone of wells. High reservoir pressure and temperature, low permeability, and complex composition impose a number of restrictions on process fluids and acid compositions for wellworks. The decrease in the filtration properties of the bottomhole zone of wells significantly depends on the impact of process fluids during drilling, development and HF. With the increase in the number of well interventions salt deposits problems come to the fore.

The article presents a design methodology for integrated treatment of the bottomhole zone to restore and maintain well productivity. The methodology includes laboratory testing of core material, sediment samples from wells and process fluids. Based on the results of laboratory studies, it was found that the use of fresh water leads to significant swelling of core samples, the core solubility in acid compositions (hydrochloric acid, clay acid) varies in a wide range (from units to tens of percent). Filtration experiments have shown that the squeezing of process fluids into the reservoir leads to a decrease in filtration properties due to swelling and clogging of the rock. It was found that the treatment composition must be selected for each well individually based on the rock lithotypes in the formation section, the properties of formation fluids and previously used process fluids. The effectiveness of design methodology is confirmed by field tests. The maximum oil production increments were obtained for the designs proposed taking into account the developed recommendations.

References

1. Manuilova E.A., Kalmykov A.G., Kalmykov G.A. et al., Complex method for core samples investigations to determine the parameters of the natural reservoirs and the main characteristics of high-carbon formations (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 4, pp. 44–47, DOI: 10.24887/0028-2448-2017-4-44-47

2. Kharakhinov V.V., Shlenkin S.I., Berin M.V. et al., New approaches to the study of bazhenov oil-bearing deposits in Western Siberia (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2015, no. 3, pp. 62–67.

3. Postnikov A.V., Postnikova O.V., Olenova K.Yu. et al., New methodological aspects of lithological research of rocks Bazhenov formation (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2015, no. 10, pp. 23–27.

4. Nemova V.D., Multi-level lithological typization of rocks of the Bazhenov formation (In Russ), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 8, pp. 13–17, DOI: 10.24887/0028-2448-2019-8-13-17

5. Afanas'ev I.S., Gavrilova E.V., Birun E.M. et al., Bazhenov Formation. Overview, problems (In Russ.), Nauchno-tekhnicheskiy vestnik OAO “NK “Rosneft'”, 2010, no. 4, pp. 20-25.

6. Trofimuk A.A., Karogodin Yu.N., Bazhenov formation - a unique natural oil reservoir (In Russ.), Geologiya nefti i gaza, 1981, no. 4, pp. 29–33.

7. Gusakov V.N., Kraevskiy N.N., Islamov R.A. et al., The rationale for selection of technologies and formulations of reagents for restoring the productivity of horizontal wells in the Vankor field (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 8, pp. 130–135, DOI: 10.24887/0028-2448-2019-8-130-135

8. Ogneva A.S., Voloshin A.I., Smolyanets E.F., Antonov M.S., Predicting and prevention asphaltene and wax deposition in oil production of the Bazhenov formation of the Priobskoye oil field (In Russ.), Neftepromyslovoe delo, 2020, no. 6, pp. 38–45, DOI: 10.30713/0207-2351-2020-6(618)-38-45

9. Ogneva A.S., Voloshin A.I., Smolyanets E.F. et al., Predicting and prevention scale deposition in oil production of the Bazhenov formation of the Priobskoye oilfield (In Russ.), Neftegazovoe delo, 2020, no. 5, pp. 61–71, DOI: 10.17122/ngdelo-2020-5-61-71

10. Kraevskiy N.N., Islamov R.A., Lind Yu.B., Selection of well killing technology for complex geological and technological conditions (In Russ.), Neftegazovoe delo, 2020, no. 4, pp. 16–26, DOI: 10.17122/ngdelo-2020-4-16-26

The article provides information on the main methods of the extraction of synthetic (kerogen) oil from oil shale and evaluates the results of the industrial implementation of these methods outside the Russian Federation. According to the US Geological Survey the geological resources of kerogen oil reach 390 billion tons (not including Russia). Oil shale processing methods are divided into ex-situ and in-situ. The main method of producing synthetic oil is the method of ex-situ retorting, while annual production volumes do not exceed 2 million tons. Currently, there are only nine active commercial projects dealing with synthetic oil production: three in Estonia and six in China. Another five projects have pilot status. None of the pilot projects related to application of in-situ methods of the synthetic oil production has entered the commercial phase. All five pilot projects based on in-situ methods in the last two decades have been closed or stopped. Major oil companies such as Shell, Chevron, ExxonMobil withdrew from all projects related to the processing of oil shale due to the high energy intensity of the processes and possible serious environmental problems. The processing of oil shale has a significant negative impact on the environment, primarily associated with groundwater and air pollution. The data presented in the article suggests that it is too early to claim a breakthrough in the development of kerogen oil.

References

1. Kucherov V.G., Bessel' V.V., Oil global geological resources and reserves assessment: myth and reality (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2021, no. 10, pp. 14–18, DOI: https://doi.org/10.24887/0028-2448-2021-10-14-18

2. Bhargava S., Awaja F., Subasinghe N.D., Characterisation of some Australian oil shale using thermal, X-ray and IR techniques, Fuel, 2005, V. 84, no. 6, pp. 707–715, DOI: https://doi.org/10.1016/j.fuel.2004.11.013

3. Geology and resources of some world oil-shale deposits, 2005, URL: https://pubs.usgs.gov/sir/2005/5294/pdf/sir5294_508.pdf

4. Oil shale (kerogen) resources and some projects in the world, 2018, URL: https://aenert.com/fileadmin/default/templates/images/Technologies/Unconventional_fossil_fuels/Shale...

5. Estonian oil shale industry yearbook 2019, URL: https://haldus.taltech.ee/sites/default/files/2021-04/ VK_eesti_polevkivitoostuse_aastaraamat_en_2019.pdf?_ga=2.94444828.1831482186.1629698087-2065338881.1627903036

6. Xu Y., Sun P., Yao S. et al., Progress in exploration, development and utilization of oil shale in China, Oil shale, 2019, V. 36, no. 2, pp. 285–304, DOI:10.3176/oil.2019.2.03

7. Pan Y., Zhang X., Liu S. et al., A review on technologies for oil shale surface retort, J. Chem. Soc. Pak., 2012, V. 34, no. 6, pp. 1331–1338.

8. Patent US7264694B2, Retort heating apparatus and methods, Inventors: Merrell B.G., Keller M.R., Noble R.K.

9. Patent US4524826A, Method of heating an oil shale formation, Inventor: Savage K.D.

10. Crawford P.M. et al., New challenges and directions in oil shale development technologies, Oil shale: A solution to the liquid fuel dilemma, Publications, 2010, pp. 21–60, DOI:10.1021/bk-2010-1032.ch002

11. Oil shales production worldwide from 2016 to 2020, 2023, URL: https://www.statista.com/statistics/1310952/oil-shales-production-worldwide/

12. Raukas A., Punning J.-M., Environmental problems in the Estonian oil shale industry, Energy & Environmental Science, 2009, V. 2, no. 7, pp. 723–728, DOI:10.1039/b819315k

13. Controversial oil substitutes sharply increase emissions, devour landscapes, 2007, URL: https://www.nrdc.org/media/2007/070611

14. Scraping the bottom of the barrel – unconventional oil could cost us the earth, 2008, URL: https://wwf.panda.org/wwf_news/?142161/Scraping-the-bottom-of-the-barrel-unconventional-oil-could-cost-us-the-earth

The article presents an analysis of the results of the calculation of downhole pressure in the trunk of a producing well according to various models of multiphase flow (No Slip, Hasan – Kabir, Beggs – Brill, Ansari, Zhang, Orkiszewski). We compared results of numerical calculations with similar models presented in Saphir and PipeSim software; we used the same set of PVT correlations for the extracted fluids properties. Test cases included various values of parameters such as the gas factor, the diameter and angle of the borehole, water cut, and fluid flow for the design area from 100 m to 3000 m. This approach allowed to test the models under consideration in all possible modes of multiphase flow. The comparison results showed good convergence. The models were also tested on Y field data obtained during hydrodynamic studies at mechanized production wells. It is established that the success of pressure forecasting by one or another calculation method mainly depends on taking into account the following parameters: the geometry of the wellbore, changes in the properties of the extracted fluids, the structure of the multiphase flow and the dynamic flow pattern in the wellbore. The analysis of the obtained results showed that it is possible to distinguish several models of multiphase flow that will be most applicable in terms of the accuracy of downhole pressure prediction. In particular, for the considered Y field, it was revealed that such models as Beggs – Brill, Hasan – Kabir, Orkiszewski can be recommended in the wells under consideration. It is also shown that, for example, the Hasan – Kabir mechanistic-empirical model should be modified for different well conditions. This can be done by selecting empirical parameters that characterize the dynamics and structure of the flow for the corresponding properties of fluids and modes of multiphase flow in the wellbore. This will allow to correctly apply the methodology and more accurately predict the bottom-hole pressure during well operation. All created calculation modules of the presented algorithms are included in the corporate software package RN-VEGA for the interpretation of hydrodynamic studies of wells.

References

1. Brill J.P., Mukherjee H., Multiphase flow in wells, Richardson, Texas: SPE, 1999, 156 p.

2. Pashali A.A., Algoritmy i matematicheskie modeli optimizatsii rezhimov raboty skvazhin v usloviyakh vysokogo gazovogo faktora (Algorithms and mathematical models for optimizing well operation modes under high GOR conditions): thesis of candidate of technical science, Ufa, 2011.

3. Yahaya A.U., Gahtani A.A., A comparative study between empirical correlations and mechanistic models of vertical multiphase flow, SPE-136931-MS, 2010, DOI: https://doi.org/10.2118/136931-MS

4. Cacho B.T., A study on different two-phase flow correlations used in geothermal wellbore modeling, Proceedings of the Geothermal Training Programme, 2015, no. 8, pp. 69−88.

5 Galkin V.I., Ponomareva I.N., Chernykh I.A. et al., Methodology for estimating downhole pressure using multivariate model (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 1, pp. 40-43, DOI: https://doi.org/10.24887/0028-2448-2019-1-40-43

6. Lekomtsev A.V., Zhelanov E.V., Chernykh I.A., Statistical approach to the evaluation of bottomhole pressure in producing wells (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 10, pp. 98−101.

7. Volkov M.G., Oil-water-gas flow calculations in vertical wells (In Russ.), Problemy sbora, podgotovki i transporta nefti i nefteproduktov, 2017, no. 3(109), pp. 9 – 42.

8. Nigmatulin R.I., Dinamika mnogofaznykh sred (The dynamics of multiphase media), Part 2, Moscow: Nauka Publ., 1987, 360 p.

9. Belozerov V.V., Rabaev R.U., Urazakov K.R. et al., Method of gas pressure optimization in producing well annulus (In Russ.), Neftegazovoe delo, 2019, V. 17, no. 5, pp. 23−32, DOI: https://doi.org/10.17122/ngdelo-2019-5-23-32

The article introduces a series of publications about new tools created by Rosneft to improve the performance in infrastructure facilities engineering for the development of oil and gas fields and implementation of general exploration and production projects, such as etalon projects, platform solutions, and information modeling (3-5D, BIM).

The article describes the main provisions of the etalon engineering methodology, including the results of a comprehensive analysis of the potential for unification of well pad options for RN-Yuganskneftegas by applying digital etalon projects. A digital etalon project is a completed engineered facility, with the exception of foundations/pile foundations, with unified design solutions, to be applied when creating information models of blocks (modules) of complex design solutions in a number of options sufficient for designing all possible configurations of a facility limited by its scope of application. The paper demonstrates that the methodological developments of Rosneft Oil Company will ensure the creation, at the industry level, of examples of mass-built oil and gas production facilities to improve the performance of hydrocarbon exploration and production projects, and the Rosneft Group companies will be able to reduce the project implementation time by optimizing the timing of scheduling the planned needs for material and technical resources and look-ahead purchase thereof simultaneously with the end product development based on pre-order specifications formed on the basis of the selected etalon project. It is expected that the etalon engineering methodology will also allow a significant reduction of the time for building 3D models of well pad infrastructure and for aligning the end products in accordance with regulatory requirements, for accepting the end products, and will reduce the time for approval of design documentation, and also improve the end products quality by eliminating collisions in the end products development through 3D modeling, will reduce the amount of uncompleted construction projects by minimizing the supply risks of material and technical resources, and will ensure the unification of the nomenclature of material and technical resources.

References

1. Kravchenko A.N., Kosarev A.S., Pavlov V.A. et al., Standard design - Moving with the times (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2020, no. 11, pp. 13–15, DOI: https://doi.org/10.24887/0028-2448-2020-11-13-15

2. Panin M.O., Kitaeva T.Yu., Experience in providing engineering & procurement services in oil and gas industry (In Russ.), Ekspozitsiya Neft' Gaz, 2023, no. 2, pp. 80–85, DOI: https://doi.org/10.24412/2076-6785-2023-2-80-85

3. Tsaplin A.S., Pupshev V.B., Glushkov E.A. et al., Improving the efficiency of project manufacturing (In Russ.), Problemy sbora, podgotovki i transporta nefti i nefteproduktov, 2020, no. 6, pp. 20–29, DOI: https://doi.org/10.17122/ntj-oil-2020-6-20-29

Nowadays, the intermittent mode is becoming one of the best ways to operate low-rate ESP wells due to its efficiency especially at the late stages of reservoir development. However, it is essential to know how to determine the best work parameters for the periodic mode to make use of its full potential. So, there is a need for complex algorithms which can be applied to handling both problems – intermittent well model creation and optimal work parameters search. The physically driven mathematical model was designed which represents a system of three key elements: “tubing – annulus – drainage area”. They are connected with each other through boundary conditions defined in the ESP intake by mass conservation equations. The optimization task can be split into two blocks. The first stage, adjusting the model to the real operational data to match calculated dynamics, is handled by introducing “adaptation” parameters which represent specifics of a certain tubing system and varying IPR curve. During the second stage, optimization itself is implemented by various optimization-aimed algorithms which objective is maximizing income while following operational and geological constraints. The results of the work are following: the model of the intermittent ESP well; a software library built around the created model for calculating the dynamics of the parameters and the production performance of wells operating in intermittent mode; complex algorithms for well model adaptation and optimization of periodic operation mode. Quality assessment of the developed model was carried out by analyzing the convergence with numerical solutions obtained using commercial software designed for numerical modeling of non-stationary multiphase filtration in pipelines. The created model showed good convergence with well-trusted commercial software. The paper also provides the results of modeling and the predictive ability of adaptation and optimization approaches on real cases from pilot fields.

References

1. Brill J.P., Mukherjee H., Multiphase flow in wells, Henry L. Doherty Memorial Fund of AIME, Society of Petroleum Engineers Inc., Richardson, Texas, 1999, 156 p.

2. Burakov I.M. et al., Integrated hydrodynamic modeling of the well-reservoir system (In Russ.), Nauchno-tekhnicheskiy vestnik OAO «NK «Rosneft’», 2009, no. 6, pp. 15-17.

3. Yudin E., Khabibullin R., Smirnov N. et al., New applications of transient multiphase flow models in wells and pipelines for production management (In Russ.), SPE-201884-RU, 2020, DOI: 10.2118/201884-RU

4. Pashali A.A., Khalfin R.S., Sil’nov D.V. et al., On the optimization of the periodic mode of well production, which is operated by submergible electric pumps in Rosneft Oil Company (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2021, no. 4, pp. 92-96, DOI: 10.24887/0028-2448-2021-4-92-96

5. Bratland O., Pipe flow 1: Single-phase flow assurance, 2009, pp. 21-92.

6. Yudin E.V., Khabibullin R.A., Smirnov N.A. et al., New Approaches to gaslift and ESP well stock production management (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2021, no. 6, pp. 67-73, DOI: 10.24887/0028-2448-2021-6-67-73

7. Ansari A.M., Sylvester N.D., Sarica C. et al., A comprehensive mechanistic model for upward two-phase flow in wellbores, SPE-20630-PA, 1994, https://doi.org/10.2118/20630-PA.

8. Gray H.E., Vertical flow correlation in gas wells, User’s manual for API 14B Surface Controlled Subsurface Safety Valve Sizing Computer Program, 2nd Edition, (Appendix B), American Petroleum Institute, Dallas, TX, 1978.

9. Hagedorn A.R., Kermit E.B., Experimental study of pressure gradients occurring during continuous two-phase flow in small-diameter vertical conduits, JPT, 1965, V. 17, pp. 475–484, DOI: https://doi.org/10.2118/940-PA

10. Topol’nikov A.S., Obosnovanie primeneniya kvazistatsionarnoy modeli pri opisanii periodicheskogo rezhima raboty skvazhiny (Justification of the application of the quasi-stationary model in the description of the periodic well operation mode), Proceedings of Institute of Mechanics. R.R. Mavlyutova, 2017, V. 12, no. 1, pp. 15–26.

11. Yudin E., Piotrovskiy G., Smirnov N. et al., Modeling and optimization of ESP wells operating in intermittent mode, SPE-212116-MS, 2022, DOI: https://doi.org/10.2118/212116-MS

12. Müller M., Dynamic time warping, Information retrieval for music and motion, 2007, pp. 69-84, DOI: https://doi.org/10.1007/978-3-540-74048-3_4

The content of hydrogen sulfide in the extracted fluid is characteristic of the oil and gas fields of the Ural-Volga region and the Caspian Sea region. The presence of hydrogen sulfide has a high effect on the corrosion destruction of the structure of oil and gas field equipment, pipelines, etc. The article discusses the effect of the mechanism of sulfide stress corrosion cracking on the casing string. As a result of a preliminary analysis of the construction of wells at the fields of Orenburgneft JSC (the subsidiary of Rosneft Oil Company), the experience of casing pipes of conventional strength groups application in the presence of hydrogen sulfide in the reservoir fluid was established, and a decision was made to conduct research work. At the first stage of the work, operational facilities containing hydrogen sulfide in the reservoir fluid were identified; its volume content and partial pressure were established. Then, according to the actually constructed and designed wells, the levels of operating operational loads of axial tension and internal pressure are calculated relative to the value of the minimum yield strength of the material of the casing pipes used. According to the actual operating conditions of casing pipes in the presence of hydrogen sulfide in the reservoir fluid, technical requirements for them have been formed. The points of these requirements are confirmed in laboratory tests of samples from seamless casing pipes of the usual strength groups for sulfide stress corrosion cracking. The developed technical requirements for seamless casing pipes used in conditions of the presence of hydrogen sulfide in the reservoir fluid at the facilities of the company are used when additional requirements are presented both for the purchase of new pipes and for the qualification of available pipes.

References

1. Osobennosti rascheta obsadnykh i liftovykh kolonn gazovykh skvazhin, kontaktiruyushchikh s flyuidami, soderzhashchimi serovodorod. Rekomendatsii (Features of the calculation of casing and lift strings of gas wells in contact with fluids containing hydrogen sulfide. Recommendations), Moscow: Publ. of VNIIGAZ, 1989, 54 p.

2.
Fedoseev D.A., Kuzichev B.F., Casing pipes and tubing for operation in
conditions of carbon dioxide activity (In Russ.), Neft'. Gaz

One of the urgent problems of oil-producing enterprises is the purification of oil from hydrogen sulfide and light mercaptans, which, having high toxicity and corrosive activity, create great environmental and technological problems. Increased attention to this issue is due to the need to comply with the technical regulations of the EAEU TR 045/2017 regulating the content of hydrogen sulfide and light mercaptans in commercial oil when being delivered to the system of trunk oil pipelines of Transneft PJSC.

The article presents a comparative assessment of the known methods of hydrogen sulfide removal in order to choose an economically feasible technological solution for the facilities of PJSC Udmurtneft named after V.I. Kudinov. Oil treatment plants at the fields of Udmurtneft PJSC allow deep dehydration and desalination of oil, vapor pressure reduction of, and water treatment. Commercial oil is pumped into the oil pipeline system of Transneft PJSC through commercial metering units of systems for measuring the quantity and quality of oil. Currently, at oil treatment plants, the content of hydrogen sulfide and light mercaptans in commercial oil does not meet the requirements of TR EAEU 045/2017. Methods that have proven themselves at other oil and gas producing enterprises, such as separation, blow-off, “soft steam”, oxidative method, and the neutralization of hydrogen sulfide with chemical reagents, are analyzed. The conclusion is made that the methods of separation and blow-off technology are inappropriate to apply at the objects under consideration. As a result of the economic evaluation of the remaining methods, it was found that the most beneficial for all objects is the oxidative method. The hydrogen sulfide neutralization with chemical reagents, the effectiveness of which has been confirmed in the conditions of the objects under study, is recommended as a fallback scenario.

References

1. Fot K.S., Kolevatov A.N., Fakhrieva G.V., Petrova O.N., Review of methods for purification of marketable oil from hydrogen sulfide (In Russ.), Neft'.Gaz.Novatsii, 2019, no. 5, pp. 32–37.

2. Fot K.S., Novikova N.V., Buldakova N.S. et al., Hydrogen sulfide converter selection for objects of Udmurtneft JSC within preparation for introduction of TR EEU 045/2017 (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2020, no. 2, pp. 68–73, DOI: https://doi.org/10.24887/0028-2448-2020-2-68-73

3. Shatalov A.N., Shipilov D.D., Sakhabutdinov R.Z., Garifullin R.M. et al., Osobennosti tekhnologiy ochistki nefti ot serovodoroda na ob"ektakh NGDU “Elkhovneft'” (Features of technologies for cleaning oil from hydrogen sulfide at the facilities of Elkhovneft), Proceedings of TatNIPIneft' / Tatneft', 2011, V. 79, pp. 279–286.

4. Sakhabutdinov R.Z., Anufriev A.A., Shatalov A.N., Shipilov D.D., Improvement of hydrogen sulfide stripping physical methods (In Russ.), Ekspozitsiya Neft' Gaz, 2017, no. 3, pp. 39–41.

5. Solov'ev V.V., Morgunova D.N., Optimization of hydrogen sulfide stripping process by example of upgrading of Aktash sulfurous crude oil treatment plant (In Russ.), Neftyanaya provintsiya, 2017, no. 3, pp. 133–140.

6. Ibragimov N.G., Sakhabutdinov R.Z., Shatalov A.N. et al., Povyshenie effektivnosti desorbtsionnoy ochistki nefti ot serovodoroda (Increasing the efficiency of desorption treatment of oil from hydrogen sulphide), Proceedings of TatNIPIneft' / Tatneft', 2016, V. 84, pp. 166–173.

7. Gilaev G.G., Rtishchev A.V., Vdovenko A.A. et al., New conceptual approach towards h2s neutralization physical methods (In Russ.), Neft'.Gaz.Novatsii, 2017, no. 10, pp. 78–82.

8. Shipilov D.D., Shatalov A.N., Sakhabutdinov R.Z., Garifullin R.M., Differentsirovannyy podkhod k resheniyu problemy ochistki nefti ot serovodoroda na ob"ektakh OAO “Tatneft'” (A differentiated approach to solving the problem of hydrogen sulfide stripping on Tatneft’s facilities), Proceedings of TatNIPIneft' / Tatneft', 2012, V. 80, pp. 284–292.

9. Shipilov D.D., Shatalov A.N., Solov'ev V.V., Ibragimov N.G., Povyshenie effektivnosti desorbtsionnoy ochistki nefti ot serovodoroda na ustanovke podgotovki nefti NGDU “Bavlyneft'” (Improving the efficiency of desorption purification of oil from hydrogen sulfide at the oil treatment unit of NGDU Bavlyneft), Proceedings of TatNIPIneft' / Tatneft', 2018, V. 86, pp. 271–277.

10. Grigoryan L.G., Devyatkin D.P., Agrafenin S.I., Development of "soft steaming" process to treat light and sour crude oil (In Russ.), Neft'.Gaz.Novatsii, 2018, no. 9, pp. 74–77.

11. Vil'danov A.F., Aslyamov I.R., Khrushcheva I.K. et al., Oxidational-catalytic DMC-1MA process for deep treatment of heavy oils for hydrogen sulfide and mercaptans (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2012, no. 11, pp. 138–140.

12. Shatalov A.N., Garifullin R.M., Shipilov D.D., Sakhabutdinov R.Z. et al., Opyt ispol'zovaniya khimicheskikh metodov ochistki nefti ot serovodoroda na ob"ektakh OAO “Tatneft'” (Experience in using chemical methods for hydrogen sulfide stripping on Tatneft’s facilities), Proceedings of TatNIPIneft' / Tatneft', 2009, pp. 371–385

One of the methods for recovering vapors of oil and oil products is their pressure absorption. It is most effectively carried out with low-volatility absorbents. The article presents the results of experimental studies of pressure absorption using a liquid-gas ejector (LGE), their comparison with the calculated values, and conclusions about the possibility of predicting the degree of capture using the apparatus of the theory of phase equilibria are made. This theory has long been successfully used in oil and gas field practice, especially under slowly changing thermodynamic conditions. There is no extreme thermodynamic parameters characteristic of reservoir systems in oil and petroleum product vapor recovery units, which allowed us to hope that the theory of phase equilibria will also be consistent in relation to the calculation of oil and petroleum product vapor recovery units. However, phase transitions occur within a limited time in the LGE, which is not typical for reservoir conditions. To study the possibility of predicting the degree of hydrocarbon capture during pressure absorption, an experimental setup was designed and manufactured. It was a closed loop made of polypropylene pipes with a pump, a liquid-gas ejector, pressure gauges, thermometers, a diesel fuel meter and a separation tank. A mixture of propane-butane with air was supplied to the ejector, where it was mixed with diesel fuel. At the inlet and outlet of the system, the concentration of hydrocarbons in the vapor-air mixture was measured. To study the possibility of predicting the degree of hydrocarbon capture during pressure absorption, an experimental setup was made containing a model of an oil reservoir, a pump, piping, LGE, a separation tank, as well as the necessary measuring instruments. According to the measurement results, the actual values of the degree of hydrocarbon vapor capture were found. In parallel, under the conditions of the experiments, this parameter was calculated using the phase equilibrium constants. The root-mean-square error of calculations was 12.6%. This confirms the possibility of using the apparatus of the theory of phase equilibria to assess the degree of hydrocarbon capture, which will be achieved in real operation at the objects of transportation and storage of oil and oil products.

References
1. Sunagatullin R.Z., Korshak A.A., Zyabkin G.V., Current state of vapor recovery when handling oil and oil products (In Russ.), Nauka i tehnologii truboprovodnogo transporta nefti i nefteproduktov = Science & Technologies: Oil and Oil Products Pipeline Transportation, 2017, no. 5, pp. 111–119, DOI:10.28999/2541-9595-2017-7-5-111-119
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The article presents a new method for locating a defect in pumping equipment using the analysis of the signal phase spectrum at specified points. The study is aimed at localization and identification of equipment defects during its operation. The proposed method is designed for defects that create periodic shock vibrations. Examples of such defects may be the destruction of the bearing, touching the moving parts of the housing, etc. Localization is proposed to be carried out using triangulation and determining the time to reach the signal from the defect to the sensors. In order to increase accuracy, the analysis of the signal phase spectrum is used. Due to the presence of a difference in signal reaching, an increasing difference in values at multiple harmonics will be observed on the signal phase spectra. Accordingly, there will be a straight line or a set of parallel lines on the phase difference graph. By determining the angle of the slope of the lines, it is possible to determine the desired difference in the time to reach the signal, and with this information, further determine the location of the defect. An equation for the numerical determination of the signal delay time is also presented. Knowing the propagation time of the signal in the equipment housing, you can determine the difference in the distance to each of the sensors. Principal possibility of using the proposed method for localization of defects is shown using an experimental stand. This approach will be relevant for new equipment for which a large experimental base for its operation has not yet been developed and a detailed defective map has not been developed. Also, the method will increase the reliability of diagnostics of existing equipment.

References

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2. Aralov O.V., Quality management methodology for complex engineering systems in major oil and oil product pipelines (In Russ.), Nauka i tehnologii truboprovodnogo transporta nefti i nefteproduktov = Science & Technologies: Oil and Oil Products Pipeline Transportation, 2019, V. 9, no. 6, pp. 608–625, DOI: 10.28999/2541-9595-2019-9-6-608-625

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DOI: 10.28999/2541-9595-2020-10-2-164-172

4. Flegentov I.A., Starshinov D.M., Mikheev Y.B., Ryabtsev E.A., Improving reliability of main pumping unit by improving bearing units (In Russ.), Science & Technologies: Oil and Oil Products Pipeline Transportation, 2022, V. 12, no. 6, pp. 569–575, DOI: 10.28999/2541-9595-2022-12-6-569-575

5. Valeev A.R., Mastobaev B.N., Movsumzade E.M., Tashbulatov R.R., Developing a method for diagnostics of oil and gas pumping equipment using three-axis strain gauge sensor (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2022, no. 1, pp. 92–95, DOI: 10.24887/0028-2448-2022-1-92-95

6. Valeev A.R., Computer simulation of the defect locating method using three-axis load cells for oil and gas pumping equipment (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2022, no. 2, pp. 112–114, DOI: 10.24887/0028-2448-2022-2-112-114

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The article deals with the issue of 3 Scope reporting on Russian oil and gas sector and foreign enterprises carbon footprint. The foreign experience of accounting for indirect greenhouse gas (GHG) emissions Scope 3 in the oil and gas sector companies is studied, and the main international standards in this area are considered. The research has been carried out to analyze current strategies for accounting for emissions from the Scope 3 of domestic oil and gas enterprises based on reports from the largest domestic players in this market. Work has been carried out on the classification of 12 the world's largest corporations in the oil and gas sector in terms of reporting categories of 3 scope GHG reporting. The results show that Russian corporations have already largely implemented the experience of foreign colleagues in using Scope 3 GHG reporting as an actual indicator in climate change control policy. In addition, an analysis was carried out on the goals that domestic companies declare to reduce GHG emissions. It shows that the goals for total carbon neutrality by 2050 are fixed in the strategic documents and reports of most corporations, in contrast to the intermediate goals on the way to this result. Analysis of the accounting practice for the Scope 3 of GHG emissions shows that there are a number of factors that do not allow for a comparative analysis of numerical indicators between different corporations in the Russian oil and gas sector.

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