Tazhong Uplift Polycycle Tectonic Evolution And Dynamic Reservoir

The Tazhong (Central Tarim) paleohigh in Tarim basin is a large scale paleohigh which experienced multiple tectonic movements during its evolutional history. As a complex large scale oil and gas accumulation region ,it displays complicated deformational and depositional patterns . On this paper ,guided by the theory of sedimentary basin dynamics ,organic geochemistry ,and the theory of complex petroleum system for multiple cyclic basins, the effect of basin tectonic evolution on the paleohigh development is systematically studied and finally the oil and gas accumulation patterns controlled by this dynamics is summarized by the author .focused on the characteristics of "multiple sources ,multiple kitchens ,multiple reservoirs ,and multiple phases of accumulation " for the paleohighs in cratonic basins in western China ,the author proposed for the first time that to reveal the accumulation patterns on paleohighs ,emphasis should be put on the reseach on the geological reconstruction in the evolutional history ,i.e, tectonic superimposement ,reservoir alternation (for example ,carstification )and pool reconstruction through the study on the dynamic processes of basin evolution -petroleum generation_reservoir formation -petroleum accumulation by synthesizing the data of geology ,geophysics and geochemitry .Based on the relationship between the paleohigh development and the basinal multi cyclic history, the dynamic processes of paleohigh are analyzed and 4 stages are identified.Based on the study on the source rocks in Tazhong (central Tarim)and the whole basin ,including source rock abundance index ,thermal history ,petroleum generation modes etc ,and the re-generation simulation of the bitumen .sandstone in the Silurian ,the new hydrocarbon supply mode of "multiple sources ,multiple phases and multiple facies"for the central Tarim is proposed by the author. The efficient source distribution areas are delimited based on these studies.The bio-mould and shoal development zone is located close to the horizons of T₇₄ and T₇²,respectively ,based on the concept of tectonic-sedimentary paleo-geography. Tectonics and exposure sequence unconformity studies reveal that distribution of the carbonate reservoir is primarily controlled by sedimentary facies and diagenesis facies(facies),tectonic location(location),carstification development stages and sequence horizons(time).The reservoir development...