Study Of The Resrvoir Conditions Of Deposition And Accumulation Of Carboniferous-Permian In Linqin Depression

The thesis adopting many synthetical research methods of Sedimentology, Lithology, Paleontology, Geochemistry, Structural Geology, Logging Geology and other subjects, combining experimentation methods and means of X-ray diffraction, petrographic thin section observation, scanning electron microscope and so on, studied Carboniferous-Permian sedimental characteristics of Linqing depression basin in Bohai Bay basin, analysed the reservoirs'characteristics and dimensional spreading features of coal-formed gas, and accumulation conditions of coal-formed gas preparing compact bases for the exploration of this area. The achievements of this thesis are as follows.The dissertation studied Neopaleozoic sedimental environments and sedimentary systems in Linqing depression basin, identified five sedimentary systems, as tidal flat system, barrier-lagoon system, delta system, river-lake system and coast- seashore without barrier system.Maybe there are littoral deposits during late Permian in Linqing depression basin. There are haidan indicatory minerals as glauconite in the upper Shihezi group and the author found gastropod fossils and lingual fossils. Combining sedimentology characteristics of Kuishan sandstone, the author arrived at a conclusion that the sedimental environment of the upper Shihezi group is haidan environment.According to the thin section identification electron microscope and casting thin sections, the reservoir bed belong to low porosity and low permeability reservoir to very low porosity and permeability sandstone reservoir, the main type is interparticle pore,the author studied the dimensional spreading features of eastern reservoirs in Linqing depression basin, finding that the reservoirs of two sides are thinner, the reservoirs of the middle are deeper and the eastern area and the middle eastern area are favorable areas.The author studied the hydrocarbon capacity of coal measure strata of this area and dark mudstone and arrived at a conclusion that the organic matter styles of the coal-formed gas in this area moatly areâ…¢style kerogen,â…¡style orâ… style for several areas.Using the vitrinite reflectance determination, the author studied thermal evolution model of this area. The author supposed the thermal evolution history of Linqing depression basin during Carboniferous-Permian are similar because of similar deposit depth and similar geothermal temperature features.