Currently the most effective way to find hydrocarbons is their prospecting in deeply buried sediments of the operated oil-producing provinces that, in its turn, is related with definite engineer and financial risks. So, the mud volcanoes of the South-Caspian Basin (SCB) can play a role of the natural deep wells and carry value information regarding the processes occurring at great depths.

The paper summarized the results of the previous and new studies of the isotopic composition of products of activity (rocks-ejects, gas, oil, water) of the mud volcanoes in the SCB with purpose to forecast the petroleum potential and phase state of HC at the depths inaccessible for drilling and minimize the economic and technological risks of expensive deep wells drilling. It is shown that the position of petroleum charges of mud volcanoes and fields in the section corresponds to the generally accepted vertical zoning of oil-and-gas generation and has a single genetic source. The increase of rocks thickness is observed from onshore towards the central deep part of the SCB and the maturity of oil and gas increases as well accompanying by the change of phase state of the HC from oil to oil-gas and gas-condensate ones. Only gas-condensate accumulations are forecasted in the deep part of the SCB. The lower limit of their generation temperature is approximately assessed as 300 °C, and corresponded to the depth range of about 8 to 16 km.

Keywords: South-Caspian basin, mud volcanoes, rocks-ejects, fluids, isotopic composition, great depths, forecast of petroleum potential


REFERENCES

Aghayeva V., Sachsenhofer R.F., van Baak C.G.C., Bechtel A., Hoyle T.M., Selby D., Shiyanova N., Vincent S.J. New geochemical insights into Cenozoic source rocks in Azerbaijan: implications for petroleum systems in the South Caspian region. Journal of Petroleum Geology, Vol. 44, No. 3, 2021, pp. 349-384.

Aliyev Ad.A., Bayramov A.A. Regularities of spatial-time distribution of mud volcanoes in the South Caspian Basin in the light of new tectonic conception. Proceedings of Geology Institute of Azerbaijan National Academy of Sciences, No. 35, 2007, pp. 25-45 (in Russian).

Aliyev Ad.A., Kabulova A.Ya. Helium isotopes in gases of the mud volcanoes of Azerbaijan. Proceedings of the Azerbaijan Academy of Sciences, Vol. 36, No. 3, 1980, c. 52-56 (in Russian).

Amado L. Reservoir exploration and appraisal || field case evaluations. Gulf Professional Publishing. 2013, pp. 53-156, ISBN 9781856178532, https://DOI.org/10.1016/B978-1-85617-853-2.00012-0

Axen G.J., Lam P.S., Grove M., Stockli D.F. Exhumation of the West-Central Alborz mountains, Iran, Caspian subsidence, and collision-related tectonics. Geology, Vol. 29, No. 6, 2001, pp. 559-562.

Bailey N.J.L., Guliyev I.S., Feyzullayev A.A. Source rocks in the South Caspian. AAPG/ASPG research symposium 'Oil and gas petroleum systems in rapidly-subsiding basins'. Book of abstracts. Baku, Azerbaijan, October 6-9 1996.

Carothers W.W., Kharaka Y.F. Stable carbon isotopes of HCO3- in oil-field waters –implications for the origin of CO2. Geochimica et Cosmochimica Acta, Vol. 44, No. 2, 1980, pp. 323-332.

Dadashev A.A., Feyzullayev A.A., Guliyev I.S. Vertical zoning of oil and gas forming by data of the isotopic composition of methane carbon of the mud volcanoes and fields in Azerbaijan. Oil and gas geology and geophysics, No. 6, 1986, pp. 24-28 (in Russian).

Dadashev A.A., Zorkin L.M., Blokhina G.G. New data about the isotopic composition of methane carbon of the natural gases of the mud volcanoes in Azerbaijan. Akademiia Nauk SSSR, Doklady, Vol. 262, No. 2, 1982, с. 399-401, DOI: 10.7868/S0024497X15010036 (in Russian).

Faber E. Zur isotopengeochemie gasformiger Kohlenwasserstoffe. Erdol, Erdgas, Kohle, Vol. 103, No. 5, 1987, pp. 210-218 (in German).

Feyzullayev A., Aliyeva Es.A. Estimation of the various source rocks contribution in oil pools formation. EAGE 65 Conference and Exhibition, Stavanger, The Norway, 2-5 June 2003. Extended Abstracts on CD, P 026, 4 p.

Feyzullayev A., Guliyev I., Tagiyev M. Source potential of the Mesozoic-Cenozoic rocks in the South Caspian Basin and their role in forming the oil accumulations in the Lower Pliocene reservoirs. Petroleum Geoscience, Vol. 7, No. 4, 2001, pp. 409-417.

Feyzullayev A., Movsumova U. The nature of the isotopically heavy carbon of carbon dioxide and bicarbonates in the waters of mud volcanoes in Azerbaijan. Geochemistry, 5, 2010, pp. 1-6 (in Russian).

Feyzullayev A., Tagiyev M. Forming of oil and gas deposits in the Productive Series of the South-Caspian basin: new approaches and results. Azerbaijan Oil Industry, No. 3, 2008, pp. 7-18 (in Russian).

Feyzullayev A.A. Mud volcanoes in the South Caspian basin: nature and estimated depth of its products. Natural Science, Vol. 4, No.7, 2012, pp. 445-453. Feyzullayev A.A., Lerche I. Temperature-depth control of petroleum occurrence in the sedimentary section of the South Caspian basin. Petroleum Research, Vol. 5, No. 1, 2020, pp. 70-76, https://doi.org/10.1016/j.ptlrs.2019.10.003

Feyzullayev A.A., Movsumova U.A. The nature of the isotopically heavy carbon of the carbon-dioxide gas of the mud volcanoes in Azerbaijan. Proceedings of the III International conference of Azerbaijan Society of Petroleum Geologists, Baku, 1995, pp. 38-39 (in Russian).

Guliyev I., Feyzullayev A. Geochemistry of hydrocarbon seepages in Azerbaijan. In: (D.Shumacher and M.Abrams, eds.) Hydrocarbon migration and its near-surface expression. AAPG Memoir, Vol. 66, 1996, pp. 63-70.

Guliyev I., Feyzullayev A., Aliyev A., Movsumova U. Composition of gases and organic matter of rocks-ejections of mud volcanoes of Azerbaijan. Oil and gas geology, No. 3, 2005, pp. 27-30 (in Russian).

Guliyev I., Feyzullayev A., Huseynov D. Fluids of mud volcanoes in the Southern Caspian sedimentary basin: geochemistry and sources in light of new data on the carbon, hydrogen, and oxygen isotopic compositions. Geochemistry, No. 7, 2004, pp. 792-800 (in Russian).

Guliyev I., Feyzullayev A., Tagiyev M. Isotope-geochemical characteristics of hydrocarbons in the South Caspian Basin. Energy, Exploration and Exploitation, Vol. 15, No. 4/5, 1997, pp. 311-368.

Guliyev I.S., Feyzullayev A.A., Guseynov D.A. Carbon isotopic composition of the hydrocarbon fluids of the South Caspian Megadepression. Geochemistry International, Vol. 39, No. 3, 2001, pp. 237-243. 

Gürgey K. Correlation, alteration, and origin of hydrocarbons in the GCA, Bahar, and Gum Adasi fields, western South Caspian Basin: geochemical and multivariate statistical assessments. Marine and Petroleum Geology, Vol. 20, No. 10, 2003, pp. 1119-1139.

Hovland M., Rueslеtten H., Lifhseth H., Fichler C., Johnsen H. Mud volcanoes – A result of supercritical water formation at depth? Proceedings of AAPG/GSTT Hedberg Conference “Mobile Shale Basins – Genesis, Evolution and Hydrocarbon Systems”, Trinidad and Tobago, 4-7 June 2006.

Jackson J., Priestley K., Allen M.B., Berberian M. Active tectonics of the South Caspian Basin. Geophys. J. Intern., Vol. 148, No. 2, 2002, pp. 214-245.

Jafarov S.A. Inert components (helium, nitrogen, argon isotopes) of gases of the mud volcanoes in Azerbaijan in connection with prospects of gas content and deep sediments. Abstract of the PhD dissertation, Institute of Geology of Azerbaijan Academy of Sciences, Baku, 1985 (in Russian).

Katz K.J., Richards D., Long D., Lawrence W. A new look at the components of the petroleum system of the South Caspian Basin. Journal of Petroleum Science and Engineering, Vol. 28, No. 4, 2000, pp. 161-182.

Kazmin V.G., Verzhbitskii E.V. Age and origin of the South Caspian Basin, Oceanology, Vol. 51, No. 1, 2011, pp. 131-140.

Kerimov V.Yu., Guliyev I.S., Huseynov D.A., Lavrenova E.A., Mustayev R.N., Osipov A.V., Serikova U.S. Forecast of the oil and gas content in regions with complex geological structure. Publishing House “Nedra”. Moscow, 2015, 404 p. (in Russian).

Kikvadze O.E. Geochemistry of the mud volcanic fluids of the Caucasian region. PhD thesis, Moscow, 2016, 183 p. (in Russian).

Lavrushin V.Yu., Guliyev I.S., Kikvadze O.E., Aliyev Ad.A., Pokrovskiy B.G., Polyak B.G. Waters from mud volcanoes of Azerbaijan: isotopic-geochemical properties and generation environments. Lithology and Mineral Resources, No. 1, 2015, pp. 3-29 (in Russian).

Lavrushin V.Yu., Polyak B.G., Prasolov E.M., Kamenskiy I.L. Sources of matter in the mud volcanism products (by isotopic, hydrochemical and geological data). Lithology and Mineral Resources, No. 6, 1996, pp. 625-647 (in Russian).

Mazzini A. Mud volcanism: processes and implications. Marine and Petroleum Geology, Vol. 26, No. 9, 2009, pp. 1677-1680, DOI:10.1016/j.marpetgeo.2009.05.003 

Mustayev R.N. Conditions of forming and forecast of oil and gas content of the western side of the South-Caspian depression. PhD thesis. Gubkin Russian State University of Oil and Gas, Moscow, 2013, 123 p. (in Russian).

Nakada R., Takahashi Y., Tsunogai U., Zheng G., Shimizu H. Hattori K. A geochemical study on mud volcanoes in the Junggar Basin, China. Applied Geochemistry, Vol. 26, No. 7, 2011, pp. 1065-1076, DOI:10.1016/j.apgeochem.2011.03.011

Peters K.E. and Moldowan J.M. The Biomarker guide. Interpreting molecular fossils in petroleum and ancient sediments. Prentice Hall, Englewood Cliffs, New Jersey, 1993, 363 p.

Philip H., Cisternas A., Gvishiani A., Gorshkov A. The Caucasus: an actual example of the initial stages of continental collision. Tectonophysics, Vol. 161, 1989, pp. 1-21.

Planke S., Svensen H., Hovland M., Banks D.A., Jamtveit B. Mud and fluid migration in active mud volcanoes in Azerbaijan. GeoMarine Letters, Vol. 23, 2003, pp. 258-268, DOI:10.1007/s00367-003-0152-z

Prasolov E.M. Isotopic geochemistry and origin of the natural gases. Nedra. Leningrad, 1990, 283 p. (in Russian).

Prasolov E.M., Lobkov V.A. Regarding the conditions of formation and migration of the methane (by isotopic composition of the carbon). Geochemistry, No. 1, 1977, pp. 122-135 (in Russian).

Valyaev B.M., Grinchenko Yu.I., Erokhin V.E., Prokhorov V.S., Titkov G.A. Isotopic appearance of gases of the mud volcanoes. Lithology and Mineral Resources, No. 1, 1985, pp. 72-87 (in Russian).

Wavrek D., Collister J., Curtiss D., Quick J., Guliyev I., Feyzullayev A. Novel application of geochemical inversion to derive generation/expulsion kinetic parameters for the South Caspian petroleum system (Azerbaijan). AAPG/ASPG Research Symposium “Oil and gas petroleum Systems in rapidly subsiding basins”. October 6-9 1996. Baku, Azerbaijan.