In recent years, within the oil and gas provinces of the Russian Federation, there has been a downward trend in both the number of newly discovered hydrocarbon deposits and the volume of incremental reserves. In accordance with the energy strategy of the Russian Federation for the period up to 2030, the development of the hydrocarbon potential of the continental shelf of the Arctic seas and northern territories of Russia is called upon to play a stabilizing role in the dynamics of oil and gas production, compensating for its possible decline in traditional oil and gas producing regions of the country. However, the implementation of these projects is associated with large investments in mining and transport infrastructure. Along with this, given the fragility of the Arctic ecosystems, the costs of measures to prevent environmental risks and remediation of territories increase manifold. All these factors greatly reduce profitability and the competitiveness of Arctic projects, transferring in many respects the problem of their implementation from the economic plane to the political one. At the same time, significant resources of oil and gas can still be explored in old oil-producing regions. The study of oil and gas content at great depths (over 4.5 km) is one of such promising directions. On the territory of Russia, purposeful geological exploration work on deeply submerged subsoil horizons has been carried out since the 60s. last century. As a result of the work carried out at depths of over 4.5 km, a number of oil and gas fields were discovered. In this work, based on the materials of the state balance of mineral reserves of the Russian Federation as of 01.01.2020, an analysis of characteristics of hydrocarbon reserves of deep accumulations is presented.

References

1. Kerimov V.Yu., Osipov A.V., Oil and gas content of great depths and promising areas of geological exploration for oil and gas in deeply submerged horizons in the territory of the Russian Federation (In Russ.), Delovoy zhurnal Neftegaz.RU, 2016, no. 10, pp. 66–72.

2. Guliev I.S., Kerimov V.Yu., Osipov A.V., Mustaev R.N., Dantsova K.I., Conditions for the formation of ultra-deep hydrocarbon systems (In Russ.), Conference Proceedings, Geomodel 2018, Sep. 2018, V. 2018, pp. 1-5, DOI: 10.3997/2214-4609.201802327.

3. Kerimov V.Yu., Mustaev R.N., Osipov A.V., Features of the generation of hydrocarbons at great depths of the Earth's crust (In Russ.), Doklady Akademii nauk = Doklady Earth Sciences, 2018, V. 483, no. 3, pp. 296–300, DOI: 10.1134/S1028334X18110193.

4. Osipov A.V., Kerimov V.Yu., Vasilenko E.I., Monakova A.S., Petroleum systems formation conditions in the deeply sediments in the south-east part of the Volga-Ural oil and gas province (In Russ.), Socar Proceedings, 2019, no. 1, pp. 4–18, DOI: 10.5510/OGP20190100374.

5. 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.

The article briefly reviews the opportunities of statistical analysis application, based on the distribution function of hydrocarbon accumulations, in terms of different petroleum regions’ geological concept update. Used statistical tool was derived from Peter Roses’ investigations based on the plenty of world hydrocarbon accumulations analysis. According to it, the relationship between the accumulations’ resources and the amount of these accumulations represents almost straight line in log-lognormal scale. The article reviews the results of this method application in terms of Bukhara-Khiva petroleum region in Uzbekistan. Firstly, the essential deformation of these distribution functions had been identified because of Shurtan accumulation presence among the set of all discovered in this area accumulations. These results gave an idea of possible Shurtan location in another petroleum region. Secondly, the strong analysis of all available geological data (particularly satellite image interpretation) allowed proving the Shurtan location in adjacent Gissar petroleum region and necessity of Bukhara-Khiva region’s southeastern boundary correction. Afterwards the same was also proved by means of modified (excluding Shurtan) distribution function of hydrocarbon accumulations. Finally, the boundary between Bukhara-Khiva and Gissar petroleum regions has been reviewed based on the available geological data and statistical analysis combination. Applied statistical analysis made possible to update previous Bukhara-Khiva geological concept, based only on geological information by implication of statistical data as well.

References

1. Rose P.R., Risk analysis and management of petroleum exploration ventures, AAPG, 2012, 304 р.

2. Ermolkin V.I., Larin V.I. et al., Geologiya nefti i gaza (Geology of oil and gas), edited by Bakirov E.A., Moscow: Nedra Publ., 1990, 240 p.

3. Abidov A.A. et al., Report of IGIRNIGM JSC: “Strategicheskaya programma geologo-razvedochnykh rabot na neft' i gaz v regionakh Respubliki Uzbekistan na period 2005-2020 gg.” (Strategic program of geological exploration for oil and gas in the regions of the Republic of Uzbekistan for the period 2005-2020.),  . – Tashkent, 2004.

4. Melikhov V.N., Productivity and oil and gas potential of Amu-Darya megabasin (In Russ.), Geologiya nefti i gaza, 2009, no. 5, pp. 10-18.

5. Maksimov S.P., Pankina R.G., Smakhtina A.M., Conditions of forming hydrocarbon accumulations in the Mesozoic of Amu-Dar'ya gas-oil province (In Russ.), Geologiya nefti i gaza, 1987, no. 5, pp. 20-26.

6. Babaev A.G. et al., Neftenosnost' mezozoyskikh otlozheniy Zapadnogo Uzbekistana (Oil-bearing capacity of Mesozoic deposits of Western Uzbekistan), Tashkent: Fan, 1977, 175 p.

The article presents the results of the study of the thrust structures of the Ural fold system, located in the junction zone of the Pre-Ural regional deflection and the forward folds of the Urals, in order to identify the conditions of formation and evolution of disjunctive violations of the thrust type of the Ural region from the position of lithospheric plates tectonics and elucidate the role of the dislocations under study in localization spatial distribution of hydrocarbons. The geodynamic nature of the formation of the thrusts of the Pre-Urals is due to Hercynian orogenesis under the influence of collisional processes, and the genetically associated cover-folded structures were formed as a result of the longitudinal bending of the layered strata under the influence of horizontally oriented stress from the Ural Orogen. Despite the relatively high regional geological knowledge and development of hydrocarbon resources in the Pre-Urals, the poorly studied structures characterized by the development of fold-thrust dislocations are promising in terms of oil and gas. At present, the development of geological modeling technologies makes it possible to update previously conducted studies of the tectonic development of subthrust structures and the mechanisms of their formation. These structures are potential hydrocarbon traps. To assess the prospects for oil and gas potential in the development zone of the upstream overshoot dislocations of the Urals, paleotectonic reconstructions were made and investigated based on the implementation of kinematic modeling technology. The construction of paleotectonic reconstructions was carried out along a series of seismic profiles intersecting the northern and southern segments of the Pre-Ural regional deflection. The structures obtained allow us to study the tectonodynamic evolution of the upthrust and thrust structures and the characteristics of the formation conditions of the modern morphostructure of the sedimentary cover, and also allow us to estimate the balance of the structural plans and the direction of tectonic movements over the area and in time. The presented research results show that the fold-and-fissure thrust and sub-thrust structures of the junction zone of the Pre-Ural marginal deflection and the Forward folds of the Urals are favorable for the formation of hydrocarbon accumulations.

References

1. Kerimov V.Yu., Osipov A.V., Lavrenova E.A., The hydrocarbon potential of deep horizons in the south-eastern part of the Volga-Urals oil and gas province (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2014, no. 4, pp. 33-35. 

2. Jang Y., Kim J., Ertekin T., Sung W.M., Modeling multi-stage twisted hydraulic fracture propagation in shale reservoirs considering geomechanical factors,

SPE-177319-MS, 2015, https://doi.org/10.2118/177319-MS.

3. Nazari O.M., Darjani M., Niri M.E., 3D modeling of geomechanical elastic properties in a carbonate-sandstone reservoir: a comparative study of geostatistical co-simulation methods, Journal of Geophysics and Engineering, 2018, V. 15, no. 4, pp. 1419–1431.

4. Noufal A., Sirat M., Steiner S. et al., Estimates of in situ stress and faults/fractures in carbonate reservoirs in onshore Abu Dhabi using geomechanical forward modeling, SPE-177520-MS, 2015, https://doi.org/10.2118/177520-MS.

5. Kerimov V.Yu., Gorbunov A.A., Lavrenova E.A., Osipov A.V., Models of hydrocarbon systems in the Russian Platform–Ural junction zone (In Russ.), Litologiya i poleznye iskopaemye = Lithology and Mineral Resources, 2015, no. 5, pp. 445–458.

6. Kerimov V.Yu., Karnaukhov S.M., Gorbunov A.A. et al., Prognosis of oil and gas potential of the southern part of Ural foredeep by modeling results of generation-accumulative hydrocarbon systems (In Russ.), Geologiya nefti i gaza, 2013, no. 6, pp. 21–28.

7. Kerimov V.Yu., Kuznetsov N.B., Mustaev R.N. et al., Conditions for hydrocarbon deposits’ formation in the uplift-thrust structures of the eastern side of the Pre-Ural fore deep (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 7, pp. 36–41.

8. Kuznetsov N.B., Kerimov V.Yu., Osipov A.V. et al., Geodynamics of the Ural foredeep and geomechanical modeling of the origin of hydrocarbon accumulations (In Russ.), Geotektonika = Geotectonics, 2018, no. 3, pp. 3–20.

9. Ivanov S.N., Puchkov V.N., Ivanov K.S. et al., Formirovanie zemnoy kory Urala (Formation of the Earth's crust of the Urals), Moscow: Nauka Publ., 1986, 248 p.

10. Minligalieva L.I., Prognoz neftegazonosnosti yuzhnoy chasti Predural'skogo progiba i zony peredovykh skladok Urala na osnove geomekhanicheskogo i basseynovogo modelirovaniya (Forecast of oil and gas content of the southern part of the Cis-Ural trough and the zone of forward folds of the Urals based on geomechanical and basin modeling), Collected papers “Geologiya v razvivayushchemsya mire” (Geology in the developing world), Proceedings of XI International Scientific and Practical Conference of Students, Postgraduates and Young Scientists, Perm': Publ. of PSNRU, 2018, pp. 145–148.

11. Osipov A.V., Bondarev A.V., Mustaev R.N. et al., Results of geological survey in the eastern side of the southern part of the Pre-Urals foredeep (In Russ.), Izvestiya vysshikh uchebnykh zavedeniy. Geologiya i razvedka, 2018, no. 3, pp. 42–50.

12. Osipov A.V., Monakova A.S., Minligalieva L.I., Generatsionno-akkumulyatsionnye uglevodorodnye sistemy yuzhnoy chasti Predural'skogo kraevogo progiba (Generation-accumulation hydrocarbon systems of the southern part of the Cis-Ural foredeep), Collected papers “Novye napravleniya neftegazovoy geologii i geokhimii. Razvitie geologorazvedochnykh rabot” (New directions of oil and gas geology and geochemistry. Development of geological exploration works): edited by  Khopta I.S., Perm': Publ. of PSNRU, 2017, pp. 285–293.

13. Stupakova A.V., The Timan-Pechora basin. The structure and main stages of development (In Russ.), Georesursy, 2017, Special Issue, pp. 56–64.

The article considers the lithological features of the gamma-active rocks of the Lower Permian age within the eastern part of the Pre-Caspian basin and provides a qualitative assessment of the prospects for oil and gas potential. The authors argue the hypothesis that the bituminous siliceous-carbonate-clay formation in the regional plan is the most important object for the search accumulations of hydrocarbons. Since a number of large and giant deposits have been already discovered in the carbonate complexes, and the question of studying other promising objects, such as the gamma-active formation, remains relevant. The results of the evaluation of the structure of the void space indicate the dependence of the filtration and reservoir properties of rocks on the conditions of sedimentation and secondary processes that took place in the sediments under consideration. Thus, the study of the genesis and post-sedimentation processes of the Lower Permian bituminous formation becomes an urgent research topic for expanding the base of potential reservoirs of the Pre-Caspian basin, as well as for obtaining new information about the characteristics of the void space and the factors determining its formation. This article highlights the main regularities of the structure of gamma-active rocks and focus on the need for further development of the sedimentation model, as well as on the study of post-sedimentation processes and identifying the features of their influence on the filtration and reservoir properties of these rocks. The data obtained during the study of the object will be useful for further substantiation of the prospects for the oil and gas content of deep- water formations.

References

1. Kulumbetov G.E., Litologo-fatsial'naya kharakteristika i perspektivy neftegazonosnosti podsolevykh terrigennykh otlozheniy vostoka Prikaspiyskoy vpadiny (Lithological-facies characteristics and prospects of oil and gas content of subsalt terrigenous deposits in the east of the Caspian basin): thesis of candidate of geological and mineralogical science, St. Petersburg, 2010.

2. Iskaziev K.O., Almazov D.O., Savinova L.A. et al., Sedimentary model of the Upper Paleozoic deposits in the Karaton-Birlestik area (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 11, pp. 98–102.

3. Iskaziev K.O., Savinova L.A., Almazov D.O. et al., Facies modeling of the Temir carbonate platform based on the concept and principles of sequense stratigraphy (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 12, pp. 96–101.

4. Gur'yanov A.V., Geneticheskie tipy i vtorichnye preobrazovaniya karbonatnykh porod kak osnova dlya prognozirovaniya ikh kollektorskikh svoystv (Genetic types and secondary transformations of carbonate rocks as a basis for predicting their reservoir properties): thesis of candidate of geological and mineralogical science, Moscow, 1990, 205 p.

5. Iskaziev K.O., Ulitina L.A., Almazov D.O., Lyapunov Yu.V., Seismofacies modelling for the Lower Permian carbonate deposits in the Cyganovsko-Ulyanovskoye and Tokarevskoye fields (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 11, pp. 98–102.

6. 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.

7. Gutman I.S., Postnikov A.V., Postnikova O.V. et al., Methodical approach to vertical zonation of Bazhenov formation in relation to resources evaluation (In Russ.), Nedropol'zovanie XXI vek, 2016, no. 6, pp. 80–87.

8. Dal'yan I.B., Golovko A.Yu., On the possibility of hydrocarbon deposits at great depths in the subsalt deposits of the Eastern Caspian region (In Russ.), Ural'skiy geologicheskiy zhurnal, 2002, no. 6(30), pp. 17–24.

9. Dal'yan I.B., Golovko A.Yu., The oil-bearing chert-argillo-carbonaceous formation of Eastern Kaspian area (In Russ.), Ural'skiy geologicheskiy zhurnal, 2003, no. 1(31), pp. 17–23.

10. 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.

The object of study is the subsalt Paleozoic complex of the eastern and southeastern Caspian basin. It is noted that the increase of the porosity of the Visean, Serpukhovian, Bashkirian and Moscovian carbonate deposits is often associated with the secondary processes. Active leaching, as well as pervasive fractures and caverns formation, is one of the most important factors in the forming of void space in carbonate reservoir rocks. The authors assumed that there is a relationship between the hypergenesis processes and sea-level fluctuations (transgression and regression), considering that the key moment in the increase in the void space is dissolution during leaching. The formation of the border seas Caspian megabasin on the southeastern part of the East European Platform in the Late Devonian - Early Carboniferous implies the dependence of local sea-level changes on global eustatic fluctuations in the world ocean level. Changes in the porosity coefficient and intervals of increase in secondary porosity were compared with the scheme of relative changes in sea-level and coastline compiled by John W. Snedden and Chengjie Liu according to B.U. Haq, S.R. Shutter и A.M. Al-Qahtani, as well as a detailed comparison with transgressive-regressive cycles of the Upper Paleozoic, identified by J.G. Ogg, G. Ogg и Gradstein, F.M. based on the eustatic curve of B.U. Haq и S.R. Shutter in the research of core data from five wells (Akkuduk 1, Zhagabulak-Alibekmola 4, Zhanazhol 23, Karaton 1, and Tengiz 44).

References

1. Snedden J.W., Liu Ch., A compilation of Phanerozoic sea-level change, coastal onlaps and recommended sequence designations, Search and Discovery, 2010, no. 40594.

2. Haq B.U., Schutter S.R., A chronology of Paleozoic sea-level changes, Science, 2008, V. 322, no. 5898, pp. 64-68.

3. Ogg J.G., Ogg G.M., Gradstein F.M., A concise geologic time scale 2016, Elsevier, 2016, 240 p.

4. Iskaziev K.O., D.O. Almazov, L.A. Savinova et al., Sedimentary model of the Upper Paleozoic deposits in the Karaton-Birlestik area (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 12, pp. 102–106.

5. Iskaziev K.O., Savinova L.A., Almazov D.O. et al., Facies modeling of the Temir carbonate platform based on the concept and principles of sequense stratigraphy (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 12, pp. 96–101.

6. Iskaziev K.O., Ulitina L.A., Almazov D.O., Lyapunov Yu.V., Seismofacies modelling for the Lower Permian carbonate deposits in the Cyganovsko-Ulyanovskoye and Tokarevskoye fields (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 11, pp. 98–102.

7. 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.

The analysis of the facies distribution of reservoirs within the Moscovian-Artinskian sedimentation rim within the northern part of the Pre-Caspian basin was carried out. The Teplovsko-Tokarevskaya group of deposits is a chain of carbonate structures stretched in the sub-latitudinal direction. They are consisting mainly of bioherm structures, which include tubifytes, foraminifera, crinoidea, ostracods, ostracods, etc. From the lithological point of view, the reservoir rocks are represented by dolomite-limestone differences-from organic limestones to secondary chemogenic dolomites. The influence of facies distribution and secondary dolomitization on the structure of the pore space remains controversial and requires detailed study. The concepts of secondary dolomitization were analyzed and one of the concepts of the formation of secondary dolomites and anhydrites was used to justify the facies distribution. Secondary transformation (dolomitization) form a sweet spots zone in the Artinskian carbonate horizon when high-salinity (Mg2+) waters from the Filippovian horizon carbonates are infiltrates to Artinskian carbonate as a result of the discharge of elision waters during digenetic dehydration of gypsum. After the anhydride overlaying of the Artinskian carbonate structure, several regressive-transgressive cycles occurred, this formed a sequence of consistent dolomite-limestone and gypsum layers in the Filippovian time. During the diagenesis water contained in the gypsum was dehydrated into the permeable zones in carbonates of the Filippovian horizon, followed by unloading in the region of the Artinskian horizon. Evaporite sedimentation of chemogenic carbonates and gypsum created a condition for the subsequent infiltration of sulphate and magnesium waters in the direction dip formation angle. The source of magnesium is the water remaining after the precipitation of gypsum and carbonates in the Filippovian time.

References

1. Albertini C., Bigoni F., Francesconi A. et al., Carbonate reservoir 3D model diagenetic characterization – Karachaganak field – Kazakhstan, SPE-196673-MS, 2019, https://doi.org/10.2118/196673-MS.

2. Kohout F.A., Henry H.R., Banks J.E., Hydrogeology related to geothermal conditions of the Floridan Plateau, In: The geothermal nature of the Floridan Plateau: edited by Smith K.L., Griffin G.M., Florida Department of Natural Resources Bureau, Geology Special Publications, 1977, V. 21, pp. 1–34.

3. Adams J.E., Rhodes M.L., Dolomitization by seepage refluxion, American Association of Petroleum Geologists Bulletin, 1960, V. 44, pp. 1912–1920.

4. Mehmood M., Yaseen M., Khan E.U. et al., Dolomite and dolomitization model – a short review, Int. J. Hydro, 2018, no. 2(5), pp. 549‒553, DOI:10.15406/ijh.2018.02.00124.

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

6. Guangwei Wang, Pingping Li,Fang Haoa, Huayao Zou, XinyaYua, Dolomitization process and its implications for porosity development in dolostones: A case study from the Lower Triassic Feixianguan Formation, Jiannan area, Eastern Sichuan Basin, China, Journal of Petroleum Science

The objective of this work was to study the autigenic mineralization, its stages, and its influence on the reservoir properties of terrigenous reservoirs in the northern part of the Nepa-Botuoba anteclise. It is based on the core material of deep well sections with contrasting reservoir properties. A special influence on the reservoir properties of the rocks was exerted by the autigenic mineralization, manifested both in the pore and fractured space. In the fractured zones, such minerals as phlogopite, barite, sphalerite, pyrite with an admixture of arsenic compounds, chalcopyrite, rhodochrosite, sanidine, analcime, celestine, cuboargyrite, calcite, dolomite, magnesite, anhydrite, halite. The presence of these mineral parageneses indicates the active development of hydrothermal processes in the productive deposits of the Vendian. A sequential change of regenerative quartz cement to carbonate, sulfate, and halite cements in the pore space was revealed. The autigenic mineralization shown in reservoir rocks significantly reduces the reservoir properties and prevents both vertical and lateral fluid migration. The porosity of reservoir rocks located at a distance from hydrothermal mineralization zones can reach 20%, and the permeability is 1 mkm2. Class II and III reservoirs will be distributed in such zones. The porosity of reservoir rocks located near hydrothermal mineralization zones does not exceed 15%, and the permeability is 0,250 mkm2. Class III and IV reservoirs will be distributed in such zones. The void space of the Vendian terrigenous reservoir rocks of the Nepa-Botuoba anteclise is the result of a multi-stage change of mineral parageneses formed at the stages of regional background lithogenesis of immersion, as well as due to a complex combination of local superimposed types of lithogenesis, especially hydrothermal-metasomatic.

References

1. URL: https://neftegaz.ru/news/dobycha/483817-rng-vvela-v-promyshlennuyu-ekspluatatsiyu-vostochnye-bloki-s...

2. Fomin A.M., Dan'kina T.A., Distribution of reservoir rocks in oil and gas horizons in the northeastern part of the Nepa-Botuobinskaya anteclise (In Russ.), Izvestiya Tomskogo politekhnicheskogo universiteta, 2010, V. 316, no. 1, pp. 57–61.

3. Plyusnin A.V., Conceptual model sedimentological Botuoba productive horizons of Srednebotuobinskoye oil and gas condensate deposit (In Russ.), Vestnik VGU. Seriya: Geologiya, 2019, no. 2, pp. 61–69.

4. Kosachuk G.P., Burakova S.V., Butochkina S.I. et al., On the formation of oil deposits (rims) of the Nepa-Botuobinskaya anteclise  (In Russ.), Vesti gazovoy nauki, 2013, no. 5(16), pp. 114–123.

5. Akulov N.I., Vallev R.R., Peculiarities of the Srednebotuobinsk oil-and-gas deposit geological structure (In Russ.), Izvestiya Irkutskogo gosudarstvennogo universiteta. Seriya: Nauki o Zemle, 2016, V. 18, pp. 3–13.

6. Postnikov A.V., Postnikova O.V., Iz"yurova E.S. et al., Evolution of the processes of mineral formation in Early Vendian terrigenous rocks of the Nepa–Botuoba anteclise (In Russ.), Litologiya i poleznye iskopaemye = Lithology and Mineral Resources, 2019, no. 1, pp. 31–43.

7. Zoloeva G.M., Postnikova O.V., Iz"yurova E.S. et al., The prediction of salinization Lower Vendian terrigenous reservoir rocks of Nepsko-Botuobinskaya anteclise (In Russ.), Geofizika, 2019, no. 2, pp. 8–15.

8. Khanin A.A., Porody-kollektory nefti i gaza neftegazonosnykh provintsiy SSSR (Reservoir rocks of oil and gas of the USSR petroliferous provinces), Moscow: Nedra Publ., 1969, 368 p.

The article considers the geological structure of the Tengiz-Karaton uplift zone, the history of the geological development of this area and adjacent zones and analyzes information on 12 oil samples collected within the Tengiz-Karaton uplift zone and 2 oil samples collected at the South Emba high. The studies included analysis of the physical and chemical properties and composition of oil, analysis of gas chromatography data, biomarker analysis, and carbon isotope analysis. According to the results of the caried out analyses, two families of oils were identified, which correspond to two source rocks. Oil such as that extracted from the Serpukhov horizon of Tengiz field is characteristic of reef reservoirs that are widely distributed within the Volga-Ural and Timan-Pechora hydrocarbon provinces and are associated with Domanic source rocks. This high-carbon clay-siliceous-carbonate formation was formed in a relatively deep-water basin, during the formation of which the sedimentation conditions changed from deep-sea to shallow-sea. In terms of the amount of isoprenoids and normal alkanes, as well as the distribution of regular steranes, domanic oils are very similar to the deep oil of the Tengiz field, selected from the Serpukhov reservoir. However, the distribution of normal alkanes in this oil indicates the Early or Middle Devonian age of the source rocks, which suggests the existence of uncompensated sedimentation conditions in this time interval. Based on the geological structure of the territory, most likely, the source of generation is located in the Caspian Sea area. The other oils, both from the postsalt and from the subsalt horizons, probably have a single source rock according to the totality of geochemical characteristics. Presumably, these oils were generated in normal marine sediments of Carboniferous age (the Moscow time), and migration to the postsalt complex occurred in areas where salts are pinched out.

References

1. Glubinnoe stroenie i mineral'nye resursy Kazakhstana (Deep structure and mineral resources of Kazakhstan), Part 3. Neft' i gaz (Oil and gas): edited by Daukeev S.Zh., Uzhkenov B.S., Abdulin A.A. et al., Almaty:  Publ. of Informatsionno-analiticheskiy tsentr geologii i mineral'nykh resursov Respubliki Kazakhstan, 2002, 248 p.

2. Report on the geochemical properties, correlation and provenance of oils from the Kazakhstan and Russian sectors of the Pre-Caspian Basin, Simon Petroleum Technology Limited Exploration Services, United Kingdom, 1994.3. Tissot B.P., Welte D.H., Petroleum formation and occurrence, Springer-Verlag Telos, 1984, 699 p.

4. Jacobson S.R., Hatch J.R., Teerman S.C., Askin R.A., Middle Ordovician organic matter assemblages and their effect on Ordovician-derived oils, AAPG Bull., 1998, V. 72, pp. 1090–1100.

5. Peters K.E., Walters C.C., Moldowan J.M., The biomarker guide. V. 2. Biomarkers and isotopes in petroleum exploration and Earth history, Cambridge University Press, 2004, pp. 475–635.

6. Palacas J.G., Carbonate rocks as sources of petroleum: geological and chemical characteristics and oil-source correlations, Proceedings of the Eleventh World Petroleum Congress, 1983, V. 2, Chichester, UK, pp. 31–43.

7. Connan J., Cassou A.M., Properties of gases and petroleum lipids derived from terrestrial kerogen at various maturation levels, Geochim. Cosmochim. Acta, 1980, V. 44, pp. 1–23.

8. Waples D.W., Machihara T., Biomarkers for geologists: a practical guide to the application of steranes and triterpanes in petroleum exploration, Tulsa, AAPG, 1991, 91 p.

9. Stupakova A.V., Fadeeva N.P., Kalmykov G.A. et al., Criteria for oil and gas search in Domanic deposits of the Volga-Ural Basin (In Russ.), Georesursy, 2015, no. 2, pp. 77–86.

10. Kiryukhina T.A., Bol'shakova M.A., Stupakova A.V. et al., Lithological and geochemical characteristics of Domanic deposits of Timan-Pechora Basin (In Russ.), Georesursy, 2015, no. 2, pp. 87–100.

11. Abilkhasimov Kh.B., Osobennosti formirovaniya prirodnykh rezervuarov paleozoyskikh otlozheniy Prikaspiyskoy vpadiny i otsenka perspektiv ikh neftegazonosnosti (Features of the formation of natural reservoirs of the Paleozoic sediments of the Caspian basin and assessment of the prospects of their oil and gas potential), Moscow: Publ. of Academy of Natural Sciences, 2016, 244 p.

The article presents the results of studies of the oil and gas source properties of rocks of the Paleozoic complex, distributed within the southern part of the Pre-Ural foredeep. Despite the fact that work on the study of the southern part of the Pre-Ural foredeep has been going on for a relatively long time, the territory today remains underexplored by modern methods and the actual data on the area are very fragmentary. Today, the involvement of new facilities that will change the structure of hydrocarbon reserves is highly relevant, and there are prerequisites for the opening of such facilities in the region. There are four oil and gas complexes in the study area: Lower Permian, Visean-Bashkirian, Frasnian-Tournaisian and Lower Devonian-Frasnian. Oil and gas source rocks of all oil and gas complexes were characterized by 299 samples from 27 wells drilled in the study area. Also, 86 samples of rocks of the Silurian age were studied, which were taken in a quarry near the city of Kuvandyk. These rocks were also identified as source rocks. All samples were studied by the Rock-Eval method, which made it possible to determine the spectrum of parameters reflecting the qualitative and quantitative characteristics of the organic matter of the rocks. For all oil source rocks of oil and gas bearing complexes, maps of variability of geochemical parameters were built over the area. For the total organic carbon content and hydrogen indices in mature source rocks, calculations of their initial contents were carried out. Most of the samples studied are excellent in organic carbon content. Most of the samples of oil source rocks are characterized by II and II / III types of kerogen, therefore, they generated oil and gas. As a result of the research, maps were created on the distribution of the geochemical parameters of the Lower Permian oil and gas complex as the most studied one. It was found that the catagenetic transformation of organic matter increases towards the southern part of the study area.

References

1. Nefedova A.S., Osipov A.V., Ermolkin V.I., The source rock generation potential of lower Permian artinsckian age in southern part of Pre-Ural fore deep, Proceedinga of 18th science and applied research conference on oil and gas geological exploration and development, Geomodel – 2016, Gelendzhik, 2016, pp. 464–468.

2. Osipov A.V., Bondarev A.V., Mustaev R.N. et al., Results of geological survey in the eastern side of the southern part of the Pre-Urals foredeep (In Russ.), Izvestiya vysshikh uchebnykh zavedeniy. Geologiya i razvedka, 2018, no. 3, pp. 42–50.

3. Sinitskiy A.I., Osobennosti geologicheskogo stroeniya i perspektivy neftegazonosnosti zony sochleneniya Prikaspiyskoy vpadiny i Predural'skogo progiba (Features of the geological structure and prospects of oil and gas content of the junction zone of the Caspian depression and the Ural trough): thesis of candidate of geological and mineralogical science, Moscow, 2008.

4. Peters K.E., Cassa M.R., Applied source rock geochemistry, AAPG Memoir 60, 1994, pp. 93–120.

5. Monakova A.S., Osipov A.V., Bondarev A.V., Minligalieva L.I., Geokhimicheskaya kharakteristika neftematerinskikh porod siluriyskogo vozrasta yuzhnogo segmenta Predural'skogo progiba (g. Kuvandyk) (Geochemical characteristics of source rocks of the Silurian age in the southern segment of the Cis-Ural trough (Kuvandyk city)), Collected papers “Novye idei v naukakh o Zemle” (New ideas in Earth sciences), Proceedings of XIV International Scientific and Practical Conference, 2019, pp. 69–70.

The results of the interpretation of pyrolytic studies of the Jurassic deposits of the Uvat group of deposits (West Siberian oil and gas province) are presented. A detailed study is due to the significant prospect of their oil and gas potential. The content of organic carbon, the stages of thermal maturity, the type of kerogen and the generation potential for the parent rocks are determined. An attempt was made to identify the patterns of changes in the catagenetic transformation of the organic matter scattered in the rocks of the studied layers. Due to the history of the sedimentation basin, the western part is more submerged than the eastern part. The location of the studied areas has a north-west - south-east trend, which is obviously controlled by a system of deep faults. The issue of oil typification is important in exploration work. The oils in the areas under consideration are deposited in reservoirs of different ages, which is why it is important to determine which oil source strata they were generated by. The correlation between oil and the organic matter of the proposed oil source strata can be proved only on the basis of the regularities of the distribution of hydrocarbons at the molecular level. In addition to geological methods, a complex of chemical-bituminological studies was used for each area to identify oil-source rocks of different categories (with different oil-and-gas-source potential and different degrees of catagenetic transformation). It included the determination of the content of organic carbon and bitumoids in the rock, gas-liquid chromatography, chromatography-mass spectrometry, determination of the elemental composition of bitumoids and kerogen, and Rock-Eval pyrolysis. To determine the type of kerogen and its position relative to the zones of oil and gas formation, the Van Crevelen diagram in the coordinates of the atomic ratios of the elemental composition of kerogen and its modification for pyrolytic data were used.

References

1. Peters K.E., Walters C.C., Moldowan J.M., The Biomarker guide, V. 1. Biomarkers and isotopes in the environment and human history, United Kingdom at the Cambridge University Press, 2005, V. 1.

2. Tissot B.P., Welte D.H., Petroleum formation and occurrence, Springer-Verlag Telos, 1984, 699 p.

3. Bordyug E.V., Geneticheskie tipy neftey produktivnykh otlozheniy yugo-vostochnoy chasti Zapadnoy Sibiri (Genetic types of oils in productive deposits of the southeastern part of Western Siberia): thesis of candidate of geological and mineralogical science, Moscow, 2012.

4. Dantsova K.I., Khafizov S.F., Geological and geochemical studies of the southern regions of the West Siberian oil and gas province (In Russ.), Conference Proceedings, Geomodel 2020, Sep 2020, V. 2020, p.1 – 5, DOI: https://doi.org/10.3997/2214-4609.202050053.

5. Krasnoyarova N.A., Geokhimiya organicheskogo veshchestva nizhney yury Zapadnoy Sibiri (Geochemistry of organic matter of the Lower Jurassic): thesis of candidate of geological and mineralogical science, Tomsk, 2007.

6. Komkov I.K., Mozhegova S.V., Dakhnova M.V., Dolmatova I.V., Organic matter geochemistry and the assessment of hydrocarbon migration from the Mid-Jurassic source rocks within Karabashskaya area (In Russ.), Geologiya nefti i gaza, 2016, no. 6, pp. 79–86.

7. Fomin A.N., Kontorovich A.E. Krasavchikov V.O., Katagenez organicheskogo veshchestva i perspektivy neftegazonosnosti yurskikh, triasovykh i paleozoyskikh otlozheniy severnykh rayonov Zapadno-Sibirskogo megabasseyna (In Russ.), Geologiya i geofizika, 2001, no. 11-12, pp. 1875-1887.

8. Gordadze G.N., Giruts M.V., Koshelev V.N., Application of organic geochemistry methods for exploration and development of oil fields (In Russ.), Burenie i neft', 2020, no. 1, pp. 32-39.

9. Shimanskiy V.K., Shapiro A.I., Vasil'eva V.F. et al., Features of the composition of bitumoids of dispersed organic matter mudstones of Mesozoic deposits in the south of Western Siberia (In Russ.), Neftegazovaya geologiya. Teoriya i praktika, 2006, V. 1, URL: http://www.ngp.ni/rub/1/09.pdf

Gas chromatography and gas chromatography / mass spectrometry methods are used to analyze crude oils obtained from southern and northern blocks of Halabja field in eastern part of Iraqi Kurdistan, using different biomarkers coefficients. Biomarkers characterization is used to provide information on the source of the organic matter, depositional environment, degree of maturity, age determination of the crude oils. The data which was used is including normal alkanes and acyclic isoprenoids distributions, terpans, hopanes, steranes and diasternes aliphatic biomarkers, the distribution of aromatic biomarkers naphthalenes, dibenzothiophene, phenanthrene. The oil samples from the southern and northern blocks of Halabja are characterized by a low Pr/Ph ratio (< 1.0), a relatively low and absent oleanane and lupan ratios, an abundance of moderate C29 regular steranes and diasteranes, a relatively low C27 sterane, the presence of tricyclic terpenes, relatively low dibenzothiophene / phenanthrene ratios etc. All biomarker parameters indicates that the source rocks of the oils from southern and northern blocks of Halabja are represented by clay-carbonate and clay sediments with II-III types of organic matter were deposited under anoxic ─ reducing marine environments and were generated at high stage of maturity. All of the age diagnosed biomarker parameters indicate a Cretaceous source of oils from the south part of Halabja and a Jurassic source in oil from the northern part.

References

1. Khama Amin R.A., Hydrocarbon potential of southeast Iraqi Kurdistan: Geochemical characteristics of the Upper Cretaceous Shiranish formation point to its high potential (In Russ.), Oil&Gas Journal Russia, 2017, no. 8 (118), pp. 50–55.

2. Al-Ameri T.K., Zumberge J., Markarian Z.M., Hydrocarbons in the Middle Miocene Jeribe Formation, Diyala Region, NE Iraq, Journal of Petroleum Geology, 2012, V. 34(2), pp. 199–216.

3. Hama Amin R.A., Khafizov S.F., Kosenkova N.I., Trunova M.I., Characterization and oil-oil correlation for the Mil Qasim and Sarqala oilfields based on biomarkers analysis, Kurdistan, Northern Iraq, Proceedings of Gubkin Russian State University of Oil and Gas, 2020, no. 4, pp. 7–25.

4. Mohialdeen I.M.J., Hakimi M.H., Al-Beyati F.M., Geochemical and petrographic characterization of Late Jurassic-Early Cretaceous Chia Gara Formation in Northern Iraq: palaeoenvironment and oilgeneration potential, Mar. Pet. Geol., 2013, V. 43, pp. 166–177.

5. Peters K.E., The Biomarker guide, V. 1. Biomarkers and isotopes in petroleum systems and human history, United Kingdom at the Cambridge University Press, 2005, V. 1, 471 p.

6. Peters K.E., Walters C.C., Moldowan J.M., The Biomarker guide, V. 2. Biomarkers and isotopes in petroleum systems and Earth history, United Kingdom at the Cambridge University Press, 2005, V. 2, 684 r.

7. Dunnington H.V., Generation, migration, accumulation, and dissipation of oil in Northern Iraq, American Association of Petroleum Geologists. Reprinted by GeoArabia, 2005, V. 10, no. 2, pp. 39–84.

8. Jassim S.Z., Buday T., Middle Palaeocene –Eocene Megasequence AP10, Geology of Iraq, Published by Dolin, 2006, p. 341

9. Kent W., Hickman R.G., Norman structural development of Jebel Abd Al Aziz, Northeast Syria, GeoArabia, 1997, no. 2(3), pp. 307–330.

10. Shanmugam G., Significance of coniferous rain forests and related organic matter in generating commercial quantities of oil, Gippsland Basin, Australia, AAPG Bulletin, 1985, V. 68(8), pp. 1241–1254.

11. Waples D.W., Machihara T.,  Biomarkers for geologists: A practical guide to the application of steranes and triterpanes in petroleum geology, AAPG Methods in Exploration, 1991, no. 9, 91 p., DOI: https://doi.org/10.1017/S0016756800008529

12. Grantham P.J., Wakefield L.L., Variations in the sterane carbon number distributions of marine source rock derived crude oils through geological time, Organic Geochemistry, 1988, V. 12, pp. 61–73.

The geological structure of Baikit anteclise crust (Siberian craton) is very complicated and has to be studied with attention to the regional specifics. The presence of permafrost, numerous igneous bodies, and salt-bearing strata does the fault identification process in this region more sophisticated. For this purpose the Fault Mapping Methodology based on the intrusive bodies distribution has been crated during geological research and oil field modelling of the petroleum production area of Kamovsky anticline. In general, Rosneft Oil Company always put lots of attention to the adaptation of the oil field production activities to the geological phenomenon complexity and paleo processes reconstruction multivariance. According on this manner, the quality of the oil field geological models is inarching. Especially, this is very important for huge petroleum resources. As a result of 100 wells geological correlation, the position of faults (Pre-Vendian and Paleozoic age) was corrected according on igneous body “jumps” to the overlying sedimentary rocks. The geological model of oil field was supplemented with more detailed faults position done by intrusive bodies interpreted geometry. The main methodology concept is the idea that magma is intruding vertically by new or existing fault and, when the overlaying rock pressure became equal to the magma flow pressure, this flow has been changing the intruding direction to the horizontal and going by layers boundary.

This methodology can be used for the fault position identification in different sedimentary basins with magma intrusions or in boundary zones between basins and orogeny. Mapping of intrusive bodies is a key task in planning exploration work, since the Siberian platform is an ideal object for studying the influence of trap magmatism on oil and gas content, namely, identifying patterns in the distribution of oil and gas deposits in the area of trap magmatism and substantiating the most promising areas for drilling.

References

1. Kutukova N.M., Shuster V.L., Pankov M.V. et al., Integrated approach to the modeling of the carbonate reservoir with complicated trap structure in Eastern Siberia (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2009, no. 11, pp. 23–27.

2. Kontorovich A.E., Mel'nikov N.V., Surkov B.C. et al., Baykitskiy region (Baikit region), Neftegazonosnye basseyny i regiony Sibiri (Oil and gas basins and regions of Siberia), 1994, V. 6, 52 p.

3. Vasil'ev G.A., Svyaz' trappovogo magmatizma so strukturnym planom Katangskoy sedloviny i Baykitskoy anteklizy (Relationship of trap magmatism with the structural plan of the Katanga saddle and the Baikit anteclise), Collected papers “Zakonomernosti razmeshcheniya mestorozhdeniy nefti i gaza Sibirskoy platformy” (Regularities of the location of oil and gas fields of the Siberian platform), Novosibirsk: Publ. of SNIIGGIMS, 1990, pp. 49–56.

4. Alekseeva K.S., Popova L.P., Postnikov A.V., Postnikova O.V., The isotopic–geochronological age of trap formation rocks in the sedimentary section of the Baikit anteclise (In Russ.), Doklady akademii nauk = Doklady Earth Sciences, 2016, V. 470, no. 6, pp. 1–6.

5. Gazhula S.V., Features of trap magmatism in connection with the oil and gas content of the Siberian platform (In Russ.), Neftegazovaya geologiya. Teoriya i praktika, 2008, no. 3, pp. 1–8.

6. Kutukova N.M., Rekonstruktsiya geologicheskogo stroeniya, usloviy formirovaniya i prognoz uglevodorodnykh skopleniy rifeyskikh otlozheniy Kamovskogo svoda Baykitskoy anteklizy Vostochnoy Sibiri: na primere Yurubcheno-Tokhomskogo mestorozhdeniya (Reconstruction of the geological structure, formation conditions and forecast of hydrocarbon accumulations of the Riphean deposits of the Kamovsky arch of the Baikit anteclise in Eastern Siberia: on the example of the Yurubcheno-Tokhomsky field): thesis of candidate of geological and mineralogical science, Moscow, 2020.

7. Migurskiy A.V., Noskova E.S., Dinamika vnedreniya trappov i neftegazonosnost' v predelakh Yurubcheno-Tokhomskoy zony (Dynamics of the introduction of traps and oil and gas content within the Yurubcheno-Tokhomskaya zone), Proceedings of All-Russian metallogenic meeting II, Irkutsk, 1998, pp. 507–508

The article considers the assessment of the applicability of conducting low-depth electrical exploration by the method of controlled source radio-magnetotelluric sounding using unmanned aircraft systems for geological exploration. The results of the pilot tests, which were passed in several stages at the test site in the Leningrad region, are considered. At the first stage, the possibility of obtaining a useful signal against the background of electromagnetic interference from a helicopter-type unmanned vehicle was evaluated. In general, it was found that when the electromagnetic sensor is removed several meters from the body of the unmanned vehicle, the interference makes a negligible contribution to the measured field taking into account the verification of a priori information. It was analyzed the difference in the level of interference created by the helicopter engine on the recorder – magnetic field sensors system when the recorder is located directly under the helicopter and away from it. The analysis of the obtained ratios of noise and signal levels showed that electromagnetic interference from an unmanned vehicle is not significant and can be installed under the body. The final stage of the pilot tests was to conduct a survey using an unmanned vessel. The results of the inversion are compared with the work of the ground complex and well information. According to the geoelectric section, the main lithological units are restored, and the detail of the survey is comparable to ground work. According to the analysis of the materials, it is shown that the results of low-depth electrical exploration studies by modifying the method of radio-magnetic and thermal sounding with a controlled source using unmanned aircraft systems confirmed the possibility of obtaining conditioned materials using the technology of low-depth electrical exploration.

References

1. Gordeev S.G., Sedel'nikov E.S., Tarkhov A.G., Elektrorazvedka metodom radiokip (Electrical prospecting by radio kip method), Moscow: Nedra Publ., 1981, 132 p.

2. Saraev A., Simakov A., Shlykov A., Tezkan B., Controlled source radiomagnetotellurics: a tool for near surface investigations in remote rejoins, J.Appl. Geophys., V. 146, pp. 228–237.

3. Shlykov A.A., Saraev A.K., Estimating the macroanisotropy of a horizontally layered section from controlled-source radiomagnetotelluric soundings (In Russ.), Fizika Zemli = Izvestiya. Physics of the Solid Earth, 2015, no. 4, pp. 128–147.

The article discusses the results of the application of a modern hardware and software complex for formation evaluation using nuclear-physical spectrometric methods at the Baytuganskoye field. Commercial oil-bearing capacity of multilayer Baytuganskoye field is allocated in deposits of Bashkirian stage of the Middle Carboniferous, the Serpukhovian stage, the Bobrikovian horizon and the Tournaisian stage of the Lower Carboniferous. BaiTex LLC is carrying out a significant amount of research work to further investigate the structure and the current reservoirs saturation of Baytuganskoye field. In particular, much attention is paid to geophysical well logging, and along with the standard ones, new modern methods are also used. In case of mature productive formations, high resolution neutron-gamma spectroscopy is the most informative when choosing advanced well-logging operations. Since 2015 at the Baytuganskoye field modern nuclear-physical spectrometry research work has been carried out by Research & Engineering Center GeotekhnoKIN LLC. Studies of newly drilled and cased wells (through the casing and even in the intervals of perforation) make it possible to quantitatively determine the elemental, mineral and fluid compositions and capacitive characteristics of the deposits. By 01.04.21, studies were carried out in 68 wells.

The article considers technologies for determining fluid saturation, material composition and capacity characteristics of rocks according to the nuclear-physical spectrometry data. The description of the hardware and software complex and methodological support for the processing and interpretation of well logging data is given. In the process of investigating the wells of the Baytuganskoye field, a library of interpretation modules for the fields of Russia and Serbia was used. The library is based on geological and geophysical data accumulated over several years, generalizations of development results, measurements on core, physical and chemical properties of fluids, including produced hydrocarbons and associated water, etc. The library covers many objects: from sedimentary deposits of the Miocene to the Cambrian and foundation rocks. This allowed the creation of an interpretation model and detailed study of the sediments. The interpretation model was created for Carboniferous deposits and includes the following rock components: limestone, dolomite, marl, anhydrite, gypsum, sandstone, siltstone and hydromica clay. Comparison of nuclear-physical spectrometry results with core analysis data showed the reliability of regarded method.

References

1. Bogolyubov E.P., Miller V.V., Kopylov S.I., Kadisov E.M., Yurkov D.I., Apparaturno-programmnye kompleksy novogo pokoleniya dlya mnogoparametricheskogo radioaktivnogo karotazha (MPRK) (New generation hardware and software systems for multiparameter radioactive logging), Collected papers “Effektivnoe upravlenie protsessami razrabotki i dorazvedki zalezhey uglevodorodov na osnove dannykh kompleksa skvazhinnykh spektrometricheskikh yaderno-fizicheskikh metodov issledovaniya” (Effective management of the development and additional exploration of hydrocarbon deposits based on data from a complex of borehole spectrometric nuclear physics research methods), Proceedings of round table 19 April 2012, Moscow: Publ. of Otkrytye sistemy, 2012, pp. 16-18,

2. Metodicheskie rekomendatsii po primeneniyu yaderno-fizicheskikh metodov GIS, vklyuchayushchikh uglerod-kislorodnyy karotazh, dlya otsenki nefte- i gazonasyshchennosti porod kollektorov v obsazhennykh skvazhinakh (Guidelines for the use of nuclear-physical methods of well survey, including the carbon-oxygen logging to evaluate oil and gas saturation of reservoir rocks in cased wells): edited by Petersil'e V.I., Yatsenko G.G., Moscow – Tver: Publ. of VNIGNI, NPTs “Tver’geofizika”, 2006, 41 p.

The article is devoted to the search for missed deposits at the Srednebotuobinsky oil-gas-condensate field, which is one of the largest oil fields in Eastern Siberia. The field has been in operation since 2013. As a result the search for new deposits in an already exploited and well-studied field, new promising objects have been identified, many of which have already been proven by drilling and will soon be put into development. Often, the vector of exploration work in most fields is directed to several main layers, while the rest of the section remains unexplored, despite the high drilling depth and the availability of 2D/3D seismic data. Using the knowledge-intensive geological and geophysical approaches applied in the perimeter of the Rosneft allowed to map promising objects in the carbonates of the Osinskian and Yuryakh horizons at the already exploited field. These reservoirs reserves will be put into development in the next 2-3 years. A new object has also been identified in the sandstones of the Khamakin horizon, where the first exploratory drilling is planned in 2022. Thanks to an integrated approach, using all available geological and geophysical data, it was possible to find additional deposits within the field, provide new reserves to support production and shift the vector of exploration from the main reservoir to new, already proven promising horizons. This project is a clear and successful example of the fact that the search for missed deposits must be carried out at any field, regardless of what stage it is at.

References

1. Vorob'ev V.S., Vilesov A.P., Bobrova O.V., Makarova I.E., Composition and conditions of Osinsky horizon generation within the limits of Verkhnechonsky field (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2013, no. 12, pp. 4-13.

2. Gayduk A.V., Al'mendinger O.A., Formation conditions and criteria for prediction of areas of improved reservoir properties ancient Vendian-Cambrian reservoirs (for example, Danilovskiy license area (East Siberia)) (In Russ.), Nauchno-tekhnicheskiy vestnik OAO “NK “Rosneft'”, 2013, no. 1, pp. 10–13.

3. Redkin N., Gaiduk A., Petrov A., Mituykov A. Sedimentary, Structural, and Migration Factors Improved Porosity and Permeability Values in Deposits Over the Basement Highs on the Nepa-botuoba Anteclise (In Russ.), Conference Proceedings, GeoBaikal 2018, DOI: https://doi.org/10.3997/2214-4609.201802037

4. Perevozchikov S.N., Dolgova E.I. et al., Terrigenous deposits of Vendian Nepsky formation: restoration of depositional settings in south-east of Nepsky-Botuobinsky anteclise (In Russ.), Nedropol''zovanie

The paper presents the results of the connate water study of the Upper Devonian organo-carbonate shale rocks of the Bym-Kungur Monocline of the Volga-Ural oil and gas-bearing province using an integrated workflow. The workflow was specially developed for low permeable shale rocks. It included the determination of 1) the pore water content (free and loosely bound types) using the Dean – Stark and evaporation methods, 2) the chemically bound water content by the thermogravimetric analysis coupled to differential scanning calorimetry and Fourier transform infrared spectroscopy, 3) the ion-salt complex composition using aqueous extracts, 4) the mineral composition by XRD analysis, 5) the cation exchange capacity (CEC) values by the modified alcoholic ammonium chloride method, 6) the organic matter quality and content by the Rock-Eval pyrolysis and 7) the lithological and petrographic description of rock sections. We studied a set of representative samples of the Sargaev, Domanic and Mendym horizons from one well with the maximum preserved natural water saturation. We found that the rock samples have a high heterogenety of the mineral and organic matter composition. The investigated samples contained residual formation water of 0.03–0.43 wt.%. The amount of chemically bound water are in a range of 0.04–1.02 wt.% and exceeds free and loosely bound water. Average of CEC of studied samples is 5.79 meq/kg and depends on the clay content. The salinity of aqueous extracts from the natural rock samples varies in the range from 0.24 to 0.94 g/L, pH – from 7.81 to 9.08. The chlorine and sodium dominate in the aqueous extract composition. The clay contents and the presence of significant amount of organic matter in the rocks define the variation of the ion-salt complex composition. The obtained results fill the knowledge gaps in the petrophysical interpretation of well logs, as well as general Domanic reservoir characterization and reserves estimation. The research novelty is in using a unique suite of laboratory methods adapted for low permeable carbonate shale rocks with the initial water content of less than 1 wt.%.

References

1. Lafargue E., Espitalie J., Marquis F., Pillot D., Rock-Eval 6 Application in Hydrocarbon Exploration, Production and in Soil Contamination Studies, Revue de l’Institut Français du Petrole, 1994, V. 53, no. 4, pp. 421–437.

2. Lopatin N.P., Emets T.P., Piroliz v neftegazovoy geologii (Pyrolysis in oil and gas geology), Moscow: Nauka Publ., 1987, 143 p.

3.  Kozlova E.V., Fadeeva N.P., Kalmykov G.A. et al., Geochemical technique of organic matter research in deposits enriched in kerogen (the Bazhenov formation, West Siberia) (In Russ.), Vestnik MGU. Seriya 4. Geologiya = Moscow University Geology Bulletin , 2015, no. 5, pp. 44–54.

4. Recommended practices for Core Analysis. RP 40, API Publishing Services, 1998, 220 p.

5. Sondergeld C.H. et al., Micro-structural studies of gas shales, SPE-131771-MS, 2010.

6. Kazak E.S., Kazak A.V., A novel laboratory method for reliable water content determination of shale reservoir rocks, Journal of Petroleum Science and Engineering, 2019, V. 183, pp. 1–19, URL: http://www.sciencedirect.com/science/article/pii/S0920410519307223.

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

8. Kazak E.S., Kazak A.V. et al., The efficient method of water content determination in low-permeable rocks of Bazhenov formation (Western Siberia) (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 7, pp. 2–7.

9. Allen Handwerger D., Keller J., Vaughn K., Improved petrophysical core measurements on tight shale reservoirs using retort and crushed samples,

SPE-147456-MS, 2011.

10. Karamov T., Bogdanovich N. et al., Pore space analysis of Domanic formation rocks, Proceedings of EAGE/SPE workshop on shale science 2019 – Shale sciences: Theory and practice, Moscow, 8–9 April 2019.

11. Karamov T., Mukhametdinova A., Bogdanovich N., Plotnikov V., Khakimova Z., Pore structure investigation of Upper Devonian organic-rich shales within the Verkhnekamsk Depression, Proceedings 19th International Multidisciplinary Scientific GeoConference SGEM 2019, Albena, 2019, DOI:10.5593/sgem2019/1.2/S06.133.

12. Gutman I.S., Potemkin G.N., Balaban I.Yu. et al., Methodical methods for specifying the pyrolytic parameters for an objective oil resources assessment of the Bazhenov formation of Western Siberia (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 10, pp. 80–85.

13. Batalin O.Yu., Vafina N.G., Forms of free-hydrocarbon capture by kerogen (In Russ.), Mezhdunarodnyy zhurnal prikladnykh i fundamental'nykh issledovaniy, 2013, no. 10, pp. 418–425.

14. Sacchi E., Michelot J., Pitsch H. et al., Extraction of water and solutes from argillaceous rocks for geochemical characterisation: Methods, processes and current understanding, Hydrogeology Journal, 2001, no. 1, pp. 17–33, https://doi.org/10.1007/s100400000113.

15. Kazak E.S., Bogdanovich N.N., Kozlova E.V., Plotnikov V.V., Porody domanikovogo gorizonta kak neorganicheskie ionity (Rocks of the Domanik horizon as inorganic ion exchangers), Proceedings of 20th Anniversary Scientific and Practical Conference on Geological Exploration and Development of Oil and Gas Fields "Geomodel 2018", 10–14 September 2018, Gelendzhik, 2018, pp. 1–4, http: //doi.org/10.3997/2214-4609.201802437.

The article provides the experience of introducing the technology of phased drilling of wells Batch Drilling in the development of the White Tiger field on the shelf of the South China Sea in the Socialist Republic of Vietnam by the Joint Vietnamese-Russian company Vietsovpetro. Examples of the use of technology in the construction of wells on block conductor No. 20 using the self-lifting floating drilling rig Tam Dao - 03 in two time stages: 1) after the installation of the lower (underwater) structure of the block conductor; 2) after the installation of the upper structure. Constructions comparison of identical wells on the wellhead platform No. 20 is given. A schematic diagram of well construction with the use of batch drilling technology is presented. As a result of the comparison, it is concluded that the additional time spent on the elimination of complications, accidents and repairs occurred during the main work time and therefore did not affect the negative values of the saved time. A comparative review of the duration of drilling wells using Batch Drilling technology and using the traditional method of drilling has been noted, the fact of significant savings of drilling solution and chemical reagents for its preparation is noted. The performance of well construction works was also analyzed. A summary table of time costs was compiled, indicating the reasons for the excess of the actual indicators over the planned ones. A comparative review identified the potential to optimize time costs through phased well construction technology, which can be broken down into two components: drilling itself and supporting work that can be carried out in parallel with drilling.

References

1. Devereux S., Practical well planning and drilling, PennWell, 1997, 524 p.

2. Kalinichenko O.I., Karakozov A.A., Zybinskiy P.V., Novye tekhnicheskie sposoby i tekhnologiya pointerval'nogo bureniya skvazhin na shel'fe (New technical methods and technology for interval drilling of wells on the shelf), Zbirnik naukovikh prats' DonNTU. Seriya Girnicho-geologichna, 2001.

3. Gao Changhong, Petroleum drilling technology, Science Press, 2017, 160 р.

The Vostochno-Alinskoye field was discovered in 2007 and is located in the Lensky District of the Republic of Sakha (Yakutia). The Khamakin regional productive horizon (reservoir B10) is the main object of oil and gas production at this field. Productive reservoir B10 is represented by a hydrophobic deposit with low permeability, abnormally low reservoir temperatures and pressure, with natural fractures. Analysis and research show that the use of water-based drilling muds when opening the Khamakin horizon reduces the reservoir properties and negatively affects the productivity of the well. The experience of using brine when drilling wells showed that a significant number of production wells did not reach the estimated potential productivity with a deviation of up to several tons per day. Based on the data obtained, research results, analysis and experience during drilling and completing of wells on the Khamakin horizon, a technology has been developed, tested and implemented that allows opening a productive formation using an oil-based mud (OBM) without negative impact on the reservoir. The technology assumes a change in the design of wells. This decision made it possible to significantly increase the initial flow rates of wells brought in from drilling.

The article discusses the results of the application of the proposed technology for the period from 2016. To assess the efficiency of the well drilling technology in the equilibrium (depression) mode on OBM in comparison with traditional methods (using water-based solutions), the productivity of the drilled wells was analyzed. It was found that the productivity of the wells of the Khamakin horizon drilled using OBM is higher than with the use of traditional technology. In addition, the use of the new technology makes it possible to reduce the well development time by more than 1.5 times.

The technology for construction of wells on the Khamakin horizon using OBM can be replicated in other fields with similar properties of productive formations.

References

1. Metodicheskie rekomendatsii po opredeleniyu podschetnykh parametrov zalezhey nefti i gaza po materialam geofizicheskikh issledovaniy skvazhin s privlecheniem rezul'tatov analizov kerna, oprobovaniy i ispytaniy produktivnykh plastov (Guidelines to determine the calculation parameters of oil and gas using well logging data with the involvement the results of core analysis, sampling and testing of productive formations): edited by Vendel'shteyn B.Yu., Kozyar V.F., Leningrad: Nedra Publ., 1988, 251 p.

2. Parfir'ev V.A., Substantiation of the technology for opening the Khamakin horizon of the Vostochno-Alinskoye field (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2020, no. 7, pp. 88–89.

3. Kalinin A.G., Levitskiy A.Z., Messer A.G., Solov'ev N.V., Prakticheskoe rukovodstvo po tekhnologii bureniya skvazhin na zhidkie i gazoobraznye poleznye iskopaemye (Practical guide to drilling technology for liquid and gaseous minerals): edited by Kalinin A.G., Moscow: Nedra-biznestsentr Publ., 2001, 450 p.

4. Parfir'ev V.A., Vaganov Yu.V., Zakirov N.N., Paleev S.A., Application of hydrocarbon-base mud during the initial opening and drilling of the productive horizon of field in the Eastern Siberia (In Russ.), Neftyanoe khozyaystvo = Oil Industry,  2019, no. 12, pp. 74–79.

The article is devoted to the localization of residual reserves in the deposits of the Pashian horizon (the main object of development of the unique Tuymazinskoye field) and the development strategy. The object is at the final stage of development, due to the formed effective development system, it is characterized by high recovery factor. At the same time, because of geological structure heterogeneity the layers of the object differ in the degree of development. The layer D3ps1 has worse filtration and capacitance properties and is more heterogeneous than the layer D3ps2-3. Comprehensive analysis was performed using information about the actual operation of wells, field data, results of field and geophysical studies, results of compaction drilling and geological and hydrodynamic modeling. It was found that the remaining recoverable reserves are localized mainly in the layer D3ps1. Based on the results of field studies and well performance analysis, geological and technical measures were carried out, the success of which confirmed the correctness of the conclusion about the presence of residual reserves in the upper part of the section. Since 2013, 78 hydraulic fracturing operations have been performed, including the introduction of linear gel technology in thin bridges (between the target reservoir and the underlying aquifer, or watered due to efficient production), which allows increasing the number of candidates and intensifying production in the most difficult conditions. Based on the created geological filtration model confirmed and refined the localization of stocks at the square, and the slit formed programme of activities (drilling of wells and sidetracks, hydraulic fracturing, remedial cementing work, the organization of the new waterflooding, differential fix, etc.), the implementation of which will allow us to maintain levels of oil production and increase reserve recovery main object of the development of the unique Tuimazinskoye field.

References

1. Lozin E.V., Arzhilovskiy A.V., Lind Yu.B., Nauchnye issledovaniya UFNII-BashNIPIneft' (UFNII-BashNIPIneft scientific research), Ufa: Publ. of BashNIPIneft', 2019, 350 p.

2. Yakupov R.F., Mukhametshin V.Sh., Problem of efficiency of low-productivity carbonate reservoir development on example of Turnaisian stage of Tuymazinskoye field (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2013, no. 12, pp. 106–110.

3. Mingulov Sh.G., Yakupov R.F., Injection capacity of wells restoration on Group of fields Tuimazinskaya (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2013, no. 7, pp. 88–91.

4. Grishchenko V.A., Bashirov I.R., Mukhametshin M.R., Bil'danov V.F., Features of application of proppant-acid fracturing technology o in the fields of the Republic of Bashkortostan (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 12, pp. 120–122.

5. Iskhakov I.A., Baymukhametov K.S., Gabitov G.Kh. et al., Lessons of development of Tujmazinskoye petroleum deposit (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2004, no. 8, pp. 12–16.

6. Baymukhametov K.S., Enikeev V.R., Syrtlanov A.Sh., Yakupov F.M., Geologicheskoe stroenie i razrabotka Tuymazinskogo neftyanogo mestorozhdeniya (Geological structure and development of the Tuimazy oilfield), Ufa: Kitap Publ., 1993, 280 p.

7. Yakupov R.F., Gimazov A.A., Mukhametshin V.Sh., Makaev R.I., Analytical method for estimating efficiency of oil recovery technology in case of bottom water-drive reservoir, verified on the hydrodynamic model (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 6, pp. 66–69, DOI: 10.24887/0028-2448-2018-6-66-69.

8.  Yakupov R.F., Mukhametshin V.Sh., Zeygman Yu.V. et al., Metamorphic aureole development technique in terms of Tuymazinskoye oil field (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 10, pp. 36-40, DOI: 10.24887/0028-2448-2017-10-36-40.

9.  Mukhametshin V.Sh., Tyncherov K.T., Filtration model of oil coning in a bottom water-drive reservoir, Periodico Tche Quimica, 2018, V. 15, no. 30, pp. 725-733.

10. Yakupov R.F., Mukhametshin V.Sh., Khakimzyanov I.N., Trofimov V.E., Optimization of reserve production from water oil zones of D3PS horizon of Shkapovsky oil field by means of horizontal wells (In Russ.), Georesursy, 2019, V. 21, no. 3, pp. 55–61, DOI: 10.18599/grs.2019.3.55-61.

Vietsovpetro has been applying hydraulic fracturing in its well since 1994. Starting from 2013, in order to increase a fracture half-length and develop a previously non-drained reserves, the measures aimed on increasing the proppant pumping per 1 meter of net pay have been implemented. Increased mass of the pumped proppant led to active proppant flowback from the bottomhole area with filling up the well bottom and reducing the well flowrate. Physical-chemical method of resin coated proppant (RCP) application was adopted as the main one for preventing the proppant flowback. The article covers the methodology of RCP lab testing in terms of its caking under various reservoir temperatures, describes the results of previously applied RCP, and identifies the reasons of its low efficiency related to noncompliance of proppant characteristics to application conditions. The research describes Vietsovpetro track record in searching and selecting new RCP for various reservoir conditions. The results of performed studies allow updating the engineering-technical requirements to hydraulic fracturing proppants supplied by a Contractor. Moreover, the RCP undergo quality acceptance testing in Vietsovpetro labs in order to correspond to the declared requirements. In 2020, five wells applied RCP for hydraulic fracturing with successful acceptance tests results. To identify shut-in timing for RCP caking, the simulation of temperature build-up has been performed as well as the studies using the bottomhole temperature sensors. The wells registered stable production with no flowback of proppant after the hydraulic fracturing. The promising directions of RCP implementation have also been identified.

References

1. Klevtsov A.S., Grishchenko E.N., Balenko P.S. et al., Features of hydraulic fracturing planning and implementation while developing the low permeable highly dissected Oligocene reservoirs of Vietnam offshore fields (In Russ.), Neftyanoe khozyaystvo, 2020, no. 9, pp. 114–118.

2. Aksenova N.A., Ovchinnikov V.P., Anashkina A.E., Tekhnologiya i tekhnicheskie sredstva zakanchivaniya skvazhin s neustoychivymi kollektorami (Technology and technical means for completing wells with unstable reservoirs), Tyumen': Publ. of TIU, 2018, 134 p.

Asphalt-resin-paraffin deposits (ARPD) are usually formed in submersible downhole equipment in fields characterized by a high content of paraffin and asphaltenes, and which are at the final stage of development. Such fields are characterized by deterioration of thermobaric reservoir conditions (decreasing the reservoir temperature), the weighting of oil due to high-carbon fractions and high water cut of the produced fluids (more than 80-90%). The process of wax crystallization in tubing most often occurs due to a decreasing temperature transported to the surface of the well product as a result of its intense heat exchange with the environment. ARPD on the inner surface of the tubing walls have a negative effect on the process of lifting the produced fluid to the surface, which is expressed in reducing the well flow rate by reducing the flow area of the tubing. It is necessary to reliably predict the interval of ARPD formation in the wellbore to improve efficiency when choosing technologies for tubing cleaning from deposits.

A method has been developed for estimating the depth of oil production wells tubing cleaning from ARPD, in which, in contrast to the known ones, the calculation of the temperature distribution in the wellbore is based on solving the equation of the heat balance of the produced fluid with the environment, not on empirical dependencies. The use of a three-phase one-dimensional gas-water-oil flow model for calculating the coefficients of the volumetric oil and water contents in the liquid phase in tubing, which takes into account not only the effect of phase slip between liquid and gas but also between water and oil, will improve the accuracy of calculating the thermal conductivity transported to the well product surface and will more reliably predict the depth of wellbore remediation. Practical application of the developed method will reduce the time required to determine the scope of remediation, and, as a result, reduce production costs by choosing the optimal remediation technology for tubing.

References

1. Akramov T.F., Yarkeeva N.R., Control deposits of paraffin, asphalt-resin components of oil (In Russ.), Neftegazovoe delo, 2017, V. 15, no. 4, pp. 67–72.

2. Khoshanov T., Shirdzhanov N., Prediction of wax deposition depth in the well (In Russ.), Neftepromyslovoe delo, 1981, no. 4, pp. 21 – 23.

3. Suchkov B.M., Khabibullin R.N., On the rational depth of running lift pipes with protective coatings into the well (In Russ.), Neftepromyslovoe delo, 1974, no. 7, pp. 19–22.

4. Suchkov B.M., Khabibullin R.N., Influence of the water cut of the well production on the temperature of the fluid flow and waxing of the riser pipes (In Russ.), Neftepromyslovoe delo, 1973, no. 10, pp. 28–30.

5. 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.

6. Brill J.P., Mukherjee H., Multiphase flow in wells, SPE Monograph, Henry L. Dogherty Series, V. 17, 1999.

7. Hasan A.R., Kabir C.S., A simplified model for oil water flow in vertical and deviated wellbores, SPE-54131-PA, 1999, https://doi.org/10.2118/54131-PA.

8. Flores J.G., Oil-water flow in vertical and deviated wells, Oklahoma: The University of Tulsa, 1997.

9. Ansari A.M., Sylvester A.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.

The approbation of an economic and technological approach to assessing the effectiveness of pipeline operation is proposed to promote the development of benchmarking methods for trunk oil pipelines energy efficiency. Besides specific energy consumption, the approach also considers several parameters of operating costs which arise with the implementation of special oil transportation technologies. Methodologically, all the characteristic operating costs depending on the technological parameters of transportation are brought to their energy equivalent using relevant price indicators. This allows for a major expansion of the benchmarking methodology application area with regard to comparing operating efficiency of oil pipelines based on the efficiency factor of trunk oil pipelines process sections. As an example, this paper includes the results of an economic and technological efficiency analysis of a non-isothermal pipeline process section where an anti-turbulent additive is applied to improve the transportation capacity. Notably, the calculation of the pipeline thermal conditions takes into account the phenomenon of the transported oil being heated by friction when oil pipelines are operated under forced conditions and the fact that the presence of an anti-turbulent additive in the oil flow reduces the intensity of heat transfer to the pipeline’s internal wall. It is demonstrated that application of anti-turbulent additives to increase the transportation capacity becomes an economically viable measure only because of additional transportation volumes. Substantial factors limiting the application of the DR technology are the anti-turbulent additive cost and hot oil losses during the transshipment process at the final destination terminal. A range of anti-turbulent additive concentrations has been determined which allows to operate the oil pipeline at a high level of cost-effectiveness.

References

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

2. Revel'-Muroz P.A. et al., Estimation of the oil pumping technology effectiveness with drag reduction agents (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2020, no. 1, pp. 90–95.

3. Sunagatullin R.Z., Kutukov S.E., Gol'yanov A.I. et al., Control of oil rheological properties by exposure to physical methods (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2021, no. 1, pp. 92–97.

4. Kutukov S.E., Fridlyand Ya.M., Kriteriy energoeffektivnosti ekspluatatsii magistral'nogo nefteprovoda (Energy efficiency criterion for the operation of a main oil pipeline), Proceedings of  V International Scientific and Practical Conference dedicated to the 20th anniversary of KAZTRANSOIL JSC, 2017, 42 p.

5. Sbornik zadach po gidravlike (Collection of problems in hydraulics): edited by Kolpakov L.G., Ufa: Neftegazovoe delo Publ., 2007, 120 p.

6. Tugunov P.I., Novoselov V.F., Transportirovanie vyazkikh neftey i nefteproduktov po truboprovodam (Transportation of viscous oils and petroleum products through pipelines), Moscow: Nedra Publ., 1983, 88 p.

7. RD-75.180.00-KTN-198-09. Unifitsirovannye tekhnologicheskie raschety ob"ektov magistral'nykh nefteprovodov i nefteproduktoprovodov (Unified technological calculations of objects of main oil pipelines and oil product pipelines), Moscow: Publ. of Giprotruboprovod, 2009, 207 p.

8. RD 39-30-139-79. Metodika teplovogo i gidravlicheskogo rascheta magistral'nykh truboprovodov pri statsionarnykh i nestatsionarnykh rezhimakh perekachki n'yutonovskikh i nen'yutonovskikh neftey v razlichnykh klimaticheskikh usloviyakh (Methodology for thermal and hydraulic calculation of trunk pipelines under stationary and non-stationary modes of pumping Newtonian and non-Newtonian oils in various climatic conditions), Ufa: Publ. of VNIISPTneft', 1979, 57 p.

9. Shtukaturov K.Yu., Ekonomiko-matematicheskoe modelirovanie vybora tekhnologicheskikh rezhimov truboprovoda (Economic and mathematical modeling of the choice of technological modes of the pipeline): thesis of candidate of physical and mathematical science, Ufa, 2004.

10. Pshenin V.V., Obosnovanie optimal'nykh rezhimov perekachki vysokovyazkikh neftey s predvaritel'nym podogrevom s uchetom kharakteristik tsentrobezhnykh nasosov (Substantiation of optimal pumping modes for high-viscosity oils with preheating, taking into account the characteristics of centrifugal pumps): thesis of candidate of technical science, St. Petersburg, 2014.

11. Zholobov V.V., Sinel'nikov S.V., Ignatenkova A.I., The prospects of dra for reducing the energy consumption of thermal stations in a "hot" pumping (In Russ.), Nauka i tehnologii truboprovodnogo transporta nefti i nefteproduktov = Science & Technologies: Oil and Oil Products Pipeline Transportation, 2019, no. 3, pp. 256–265.

12. Bronshteyn I.S., Sviridov V.P., Rivkin P.R. et al., O poteryakh zapadnosibirskikh neftey iz rezervuarov magistral'nykh nefteprovodov (On the losses of West Siberian oils from the reservoirs of main oil pipelines), collected papers “Truboprovodnyy transport nefti Zapadnoy Sibiri” (Pipeline transportation of West Siberian oil), Ufa: Publ. of VNIISPTneft', 1983, pp. 65–68.

The article considers the influence of mechanical inhomogeneity and crack-like defects on the stress state of welded joints (on the example of welded joints of trunk pipelines made of low-alloy steels). Analysis of the results of previously performed studies and existing calculation methods shows that taking into account the features of zones of mechanical inhomogeneity when assessing the bearing capacity of welded joints requires further study. The development of approaches to take into account the geometry of mechanical inhomogeneity will make it possible to assess more reasonably the degree of danger of crack-like defects depending on their location in the welded joint. The determination of the geometry of mechanical inhomogeneous zones was carried out by measuring the hardness indicators. The presented results of experimental studies show the distribution of mechanical characteristics in welded joints. The results of tensile tests of specimens with an applied surface crack-like defect in mechanical inhomogeneous zones of welded joints are presented. It is shown that the difference in the values of the strength parameters of welded joints with different defect locations reaches 10%.The obtained experimental data made it possible to create a mathematical model for determining the values of the critical stresses of welded joints, taking into account the geometry of the zones of mechanical inhomogeneity. The mathematical model is based on a combination of Prandtl's solution on the constancy of tangential stresses along the plastic strip together with the method for finding the stress discontinuity, which makes it possible to take into account edge effects at free boundaries and boundaries of zones of mechanical inhomogeneity. Comparison of the results of the calculated assessment of the strength of mechanically inhomogeneous welded joints with a crest-like defect and experimental data showed their high convergence and confirmed the reliability of the proposed model.

References

1. Tigulev E.A., Yamilev M.Z., Faktory, vliyayushchie na formirovanie slozhnoy topografii mekhanicheskoy neodnorodnosti v svarnykh soedineniyakh uglerodistykh i nizkolegirovannykh staley (Factors influencing the formation of complex topography of mechanical heterogeneity in welded joints of carbon and low-alloy steels), Collected papers “Truboprovodnyy Transport – 2020” (Pipeline Transport - 2020), Proceedings of XV International educational, scientific and practical conference, Ufa: Publ. of USPTU, 2020, pp. 203–205.

2. Neganov D.A., Makhutov N.A., Zorin N.E., Formation of requirements to reliability and security of the exploited sections of the linear part of trunk pipelines transportation of oil and oil products (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2019, no. 6, pp. 106-112.

3. Neganov D.A., Zorin E.E., Zorin N.E., Assessment of influence of surface crack-like stress concentrators on main pipeline operability (In Russ.), Nauka i tehnologii truboprovodnogo transporta nefti i nefteproduktov = Science & Technologies: Oil and Oil Products Pipeline Transportation, 2021, V. 11, no. 1, pp. 8–15.

4. Yamilev M.Z., Tigulev E.A., Yushin A.A. et al., Evaluating mechanical heterogeneity of pipelines welded joints (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2020, no. 11, pp. 128–131.

5. Yamilev M.Z., Tigulev E.A., Raspopov A.A., The assessment of the level of local strengthening of pipe steel welded connections (In Russ.), Nauka i tehnologii truboprovodnogo transporta nefti i nefteproduktov = Science & Technologies: Oil and Oil Products Pipeline Transportation, 2020, V. 10, no. 3, pp. 252–262.

6. Bakshi O.A., Mekhanicheskaya neodnorodnost' svarnykh soedineniy (Mechanical heterogeneity of welded joints), Part 1, Chelyabinsk: Publ. of ChPI, 1981, 57 p.

7. Dil'man V.L., Research of the mathematical models of the stress condition of the thin-walled heterogeneous cylindrical shells based on analytical methods (In Russ.), Vestnik YuUrGU, 2009, no. 17(150), pp. 36–58.

8. Vinokurov V.A., Kurkin S.A., Nikolaev G.A., Svarnye konstruktsii. Mekhanika razrusheniya i kriterii rabotosposobnosti (Welded structures. Fracture mechanics and performance criteria), Moscow: Mashinostroenie Publ., 1996, 576 p.

9. Adaskin A.M., Zuev V.M., Materialovedenie (metalloobrabotka) (Materials science (metalworking)), Moscow: Akademiya Publ., 2009, 288 p.