| On the guide of basic theory of petroleum geology, polycyclic basin analysis, structure analysis, complex reservoir formation analysis and the integral, dynamic, complex, superimposed and effective basic train of thought were adopted in this thesis. The methods of emphasis analysis and correlation analysis were used, abided by the technical route from region to local and again to region. Firstly, the compresso-shear basins of all the world were systematically summarized, and the features of oil and gas geology of compresso-shear basins in middle and west area, China were studied, and then the conditions of reservoir formation in north and west area of Tarim basin were compared, the characteristics of oil and gas geology of compresso-shear basins in middle and west areas was obtained. Finally, the good prospecting areas in southwest Tarim depression of Tarim basin were pointed out. The main results of this thesis as following:(l)The compressso-shear basin was defined as the basin formed by compression in strike-slip fault system and the previously formed basin partly or wholly transformed by compresso-shear structure. Therefore, the compresso-shear basins could be divided into (a) primary compresso-shear basin and (b) epigenetic compresso-shear basin, and further could be divided into weak compresso-shear basin and strong compresso-shear basin.(2) The middle and west areas of China were at extension structural setting during Paleozoic and several large and small craton blocks were developed, such as Tarim, Junggar and Sichuan. Some small ocean basins and geosynclines were developed between blocks, such as the Tianshan ocean, Kunlun ocean, Aerjin ocean and Qinlin ocean. They underwent opening and closing and finally withering away to form convergent structural setting, which resulted in uplifting of orogenic belt and settling of piedmont zone. This laid a foundation for the formation of many primary compresso-shear basins. The stress of middle and westarea had been weakened which made the depressions extended and the lakes enlarged during Jurassic and Cretaceous because the intensity of collision between the Qiangtang plate and the Gangdisi plate was relative smaller. The closing of the Yaluzangbu suture zone during Oligocene to Miocene and the intracontinental subduction towards to north of the Indian plate occurred in Himalayan piedmont zone during Pliocene to Pleistocene, caused the Himalayan mountain uplifting highly and the Henghe foredeep settling deeply. The strong activity of this movement resulted in strong compression and corresponding strike-slip and shear in middle and west areas, China, and the primary basins with several types were transformed significantly to form many epigenetic compresso-shear basins.(3)The Kuche depression, the south part depression of Junggar basin were classified to weak compresso-shear basin and the southwest depression of Tarim basin and the west Sichuan depression of Sichuan basin were classified to strong compresso-shear basin by correlation analysis of structural evolution of Mesozoic and Cenozoic, strata sediment, characteristics of source rocks and deformation pattern for these depressions.(4) Five mechanisms of reservoir formation in compresso-shear basins were summarized. They were (a) reservoir formed by the thrusting zone structural driving flow, (b) reservoir formed by convection of water solution of high pressure "close box" in deep of foredeep depression, (c) reservoir formed secondarily by mixed upwelling fluids outside the "close box" , (d) reservoir formed by driving of slope zone gravity flow , (e) mixed upwelling fluids of diapir structure.(5)The features of reservoir formation for the southwest depression of Tarim basin were (a) several marine and continental facies source rocks were developed and the resource types were rich, (b) the source rocks in deep could be linked up by fault system at compresso-shear thrusting zone, and the secondary gas reservoir formed at shallower strata, (c)the strong shear stress resulted in the features of narrow structu...
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