SOUTH-CASPIAN BASIN: Geology, Geophysics, Oil and Gas Content

NATIONAL ACADEMY SCIENCES OF AZERBAIJAN INSTITUTE OF GEOLOGY AZERBAIJAN NATIONAL COMMITEE OF GEOLOGISTS SOUTH-CASPIAN BASIN: geology, geophysics, oil and gas content Baku – 2004 Editor: Academician NASA Akif A. ALI-ZADEH SOUTH-CASPIAN BASIN: geology, geophysics, oil and gas content. Baku, “Nafta-Press”, 2004, 333 p. The book consists of reports of Azerbaijan scientists. The reports are dedicated to urgent problems of geology, geophysics and oil-gas potential in the South Caspian basin (SCB) based on results of recent investigations. Formation of oil-gas systems in the region is substantiated by specific geodynamic environment accompanied by tectonic-magmatic activation at the neotectonic stage. From positions of sequence stratigraphy there have been newly considered lithogenesis of oil-gas systems on the base of hydrodynamic peculiarities of sedimentation creating architecture of the sedimentary basin. Complex of geophysical data enables to clarify infrastructure of the SCB as well as to identify a predominant role of submerdional tensions in its formation, to study deep structures and to construct its geologic- geophysical model. There has been conducted evaluation of oil-gas potential of the basin and geochemical composition of oils and terms of their generation have been studied as well. There have been acquired significant new data on gas composition of oil-gas systems, gas –hydrate formations and mud volcanism. The book was written for a wide circle of geologists and geophysicists who are en- gaged in problems of formation of oil-gas systems in the folded structures. This issue is published upon decision of Academic Board of Geological Institute of National Academy of Sciences of Azerbaijan © “Nafta-Press”, 2004, 2 C O N T E N T S From the editor ............................................................................................................. 4 GEOLOGY Ali-Zadeh Ak.A., Aliyeva E.G. Stratigraphic architecture of Quaternary succession in the Caspian basin..................................................................................................6 Aliyeva E.G. Depositional environment and architecture of Productive Series reservoirs in the South Caspian basin. ...........................................................................19 Ismail-Zadeh A.J., Mark B.Allen. The Late Cenozoic tectonic-magmatic activation of the Caspian basin. ...........................................................................................32 Rustamov M.I. South Caspian basin – geodynamic events and processes...................46 GEOPHYSICS Abasov M.T., Aliyarov R.Yu., Kondrushkin Yu.M., Krutykh L.G., Musta- fayev R.T., Rakhmanova I.S. Thermobaric regime of a section of the South- Caspian sedimentary basin fields. ..................................................................................71 Babayev D.H., Hajiyev A.N. New data of the South-Caspian depression basement. .........89 Jabbarov M.J., Kuliyev G.G. About seismic anisotropy in the South Caspian basin (SCB)....................................................................................................................99 Kadirov F.A. Gravity model of lithosphere in the Caucasus-Caspian region.............107 Levin L., Solodilov N., Panakhi B., Kondorskaya N. The Caspian Sea region: a delineation of the thermal lithosphere, energy of seismic waves and estimation of the earthquake risk for oil and gas industry.............................................................123 Mamedov P.Z. Genesis and seismic stratigraphic model of the South Caspian Megabasin architecture ................................................................................................150 Mukhtarov A.Sh. Heat flow distribution and some aspects of formation of thermal field in the Caspian region ..............................................................................165 OIL - AND - GAS PRESENSE AND MUD VOLCANISM Aliyev A.I. Terms of oil and gas deposits accumulation in the South Caspian basin .........173 Aliyev Ad.A. Mud volcanism of the South-Caspian oil-gas basin ..............................186 Dadashev F.G. Geochemistry of natural gases of western frank of South- Caspian depression and framing mountain systems.....................................................213 Kadyrov F.A., Lerche I., Guliyev I.S., Mukhtarov A.Sh., Kadyrov A.H., Feyzullayev A.A. and Aliyev Ch.S. Mud volcanoes: deep structures, dynamics and post-explosion thermal conditions.........................................................................223 Knapp C.C. and Knapp J.H. Absheron Allochthon of the South Caspian Sea: evidence for slope instability in Response to gas hydrate dissociation........................257 Aliyev G.M., Guliyev I.S., Fedorov D.L., Levin L.E. Hydrocarbon potential of the Caspian Sea region.................................................................................................269 Feyzullayev A.A., Huseynov D.A., Tagiyev M.F. Oil source rocks and geochemistry of hydrocarbons in South Caspian basin .................................................................. 286 Muradov Ch.S. The area of formation of the South Caspian gas hydrates.................322 3 FROM THE EDITOR Scientific and scientific-production institutions in Azerbaijan have obtained rather important information on the South Caspian basin (SCB) for the last decade, namely, on geology and oil-gas potential of the region. The information is of a cer- tain interest while focusing on the problem of oil-gas potential of folded systems. It is independent geologic-structural zone of the Caucasus segment of the Mediterra- nean belt with a weak subcontinental (suboceanic?) crust and thick Meso-Cenozoic sedimentary cover (with predominant evolution of Pliocene sedimentary cover). In the deepest part it was formed in the uplifted preCambrian base. There have been discovered rich oil and gas accumulations there recently. In combination with complex geodynamic history of its formation they put it among the world’s unique oil-gas. Initial leading factors of the reservoirs formation in the system were hydrodynamic environment and sedimentation rate. Avalanche sedimentation started in the early Pliocene in the delta environment of Paleovolga resulted in the accumulation of 5-6 km sedimentary complex (Productive Series – PS) and promoted creation of architecture of this large oil-gas basin. Just in this zone for the first time there was determined direct dependence between a high sedimentation rate and nice properties of the reservoirs at big depth. Investigation of sequence stratigraphy of the basin allowed to correlate cycles of marine and deltaic sedimentation. This plays a very important role while identifying reservoirs in the sections of the complexes and during their transformation on the background of ascending waves of consolidation-disconsolation. Geologic-geodynamic terms of the basins formation resulted in the compli- cation of its infrastructure accompanied by differences in the structure of the shelf and deep zones in the west Azerbaijan and of relatively shallow shelf zone in the east Turkmenian. Structures of the Absheron-Pribalakhan silt and of the Pre-Elburs trough limit the SCB in the north and in the south respective. Geodynamic regime of these zones formation promoted evaluation on of the structures determining oil-gas potential of the system. Complex geotectonic environment of their formation was accompanied by manifestations of different thrust, shift and fault stress fields. They all evolved in a close interrelation with each other. On the whole the region is characterized by total submeridional contraction as a result of north-east compression. This allows to find out the direction of the blocks displacement resulting in the manifestation of seismic risk especially within the main oil-gas zone. Among the unique peculiarities of the SCB mud volcanoes should be em- phasized especially. Unlike those existing on the land they are characterized by huge sizes (up to 4-10 km in diameter) and by the existence of gas hydrate formations in their vents. Their wide spread in the basin allows to judge about their commercial importance. Gas-hydrate formations generating in terms of marine environment are of a special interest as well. This is not only in respect of regularities of dependence of their composition on depth but in respect of determination of thermobaric terms of 4 their generation and existence as well. And the most important thing is that this is in respect of stability of the process of gas-hydrates generation in the SCB. The SCB is characterized by a wide time range of oil-gas systems formation – form Mesozoic to Pliocene related to different facial complexes - from volcanogenic – sedimentary to sedimentary. No doubt, that lithologic types of reservoirs in deposits undergo changes in terms of unstable tectonics of the region. This makes determination of stages and zones of formation of oil-gas systems there in difficult. However, on the whole, one can determine stages of intensive accumulation of hydrocarbons associated with activation of tectonic processes and with arriving of deep fluids and with transformation of mineral and organic matter into hydrocarbons. Determination of peculiarities of formation of oil-gas systems within different lithogeodynamic complexes enables to predict their properties at depth. Academician Akif A. Ali-Zadeh 5 STRATIGRAPHIC ARCHITECTURE OF QUATERNARY SUCCESSION IN THE CASPIAN BASIN Ali-zadeh Ak.A, Aliyeva E.G. Institute

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