Exploration and development practices prove that intracratonic strikeeslip faults control the development of carbonate reservoirs and the enrichment of oil and gas in the Tarim Basin.Intracratonic strikeeslip faults a...Exploration and development practices prove that intracratonic strikeeslip faults control the development of carbonate reservoirs and the enrichment of oil and gas in the Tarim Basin.Intracratonic strikeeslip faults are characterized by short displacement,small throw and great burial depth,so there are still many controversies on their structural evolution and formation mechanisms.In order to settle these controversies,this paper firstly analyzes the geometric and kinematic characteristics of the intracratonic strikeeslip faults in the central Tarim Basin.Then,based on extensive high-accuracy 3D seismic data and 2D seismic data,the formation and evolution process of the intracratonic strikeeslip faults in the Tarim Basin are discussed deeply,and their genetic mechanisms are explored.Moreover,the following research results are obtained.First,the strikeeslip faults in the study area have the characteristics of vertical stratification,plane zonation and segmentation along the strike.Second,the movement directions of the deep transpressional strikeeslip faults are simple.The NE and NNE strikeeslip faults are sinistral,and the NNW strikeeslip faults are dextral.However,the shallow transtensional faults are more different in the movement direction.The strikeeslip faults have displacements of 400e1500 m,and they are classified as intracratonic strikeeslip faults with small slip distance.Third,the strikeeslip faults were formed in the middle Caledonian,and some faults were reactivated in the late Caledonianeearly Hercynian,late Hercynian,and Yanshanianeearly Himalayan.The distribution of faults is different in different periods.Fourth,the formation of the strikeeslip faults in the middle Caledonian is controlled by the basement heterogeneity and the compression action from the closure and subduction of the Proto-Tethys Ocean.The transtensional faults are R-shear branch faults or tensile break faults generated by the later activation of middle Caledonian strike-slip faults,and their formation is controlled by the subduction and closure of oceanic basins around the basins in different periods.In conclusion,the structural characteristics,formation&evolution and genetic mechanisms of intracratonic strikeeslip faults are in close relation to oil and gas,where great benefit of oil and gas exploration and development is achieved.Besides the Tarim Basin,the Sichuan Basin and the Ordos Basin have similar geological and structural settings,so the studies on typical basins will surely enrich and complete the theories on the intracratonic strikeeslip faults in domestic micro land blocks and multi-cycle basins and point out the direction for the discovery of more oil and gas resource.展开更多
基金Project supported by the National Major Science and Technology Project"Hydrocarbon Accumulation Law,Key Technologies and Target Evaluation of Lower PaleozoicePrecambrian Carbonate Rocks"(No.:2016ZX05004-001)PetroChina Major Science and Technology Project in the 13th Five-Year Plan"Distribution Law and Key Technologies of Ancient Carbonate Reservoirs"(No.:2019B-04).
文摘Exploration and development practices prove that intracratonic strikeeslip faults control the development of carbonate reservoirs and the enrichment of oil and gas in the Tarim Basin.Intracratonic strikeeslip faults are characterized by short displacement,small throw and great burial depth,so there are still many controversies on their structural evolution and formation mechanisms.In order to settle these controversies,this paper firstly analyzes the geometric and kinematic characteristics of the intracratonic strikeeslip faults in the central Tarim Basin.Then,based on extensive high-accuracy 3D seismic data and 2D seismic data,the formation and evolution process of the intracratonic strikeeslip faults in the Tarim Basin are discussed deeply,and their genetic mechanisms are explored.Moreover,the following research results are obtained.First,the strikeeslip faults in the study area have the characteristics of vertical stratification,plane zonation and segmentation along the strike.Second,the movement directions of the deep transpressional strikeeslip faults are simple.The NE and NNE strikeeslip faults are sinistral,and the NNW strikeeslip faults are dextral.However,the shallow transtensional faults are more different in the movement direction.The strikeeslip faults have displacements of 400e1500 m,and they are classified as intracratonic strikeeslip faults with small slip distance.Third,the strikeeslip faults were formed in the middle Caledonian,and some faults were reactivated in the late Caledonianeearly Hercynian,late Hercynian,and Yanshanianeearly Himalayan.The distribution of faults is different in different periods.Fourth,the formation of the strikeeslip faults in the middle Caledonian is controlled by the basement heterogeneity and the compression action from the closure and subduction of the Proto-Tethys Ocean.The transtensional faults are R-shear branch faults or tensile break faults generated by the later activation of middle Caledonian strike-slip faults,and their formation is controlled by the subduction and closure of oceanic basins around the basins in different periods.In conclusion,the structural characteristics,formation&evolution and genetic mechanisms of intracratonic strikeeslip faults are in close relation to oil and gas,where great benefit of oil and gas exploration and development is achieved.Besides the Tarim Basin,the Sichuan Basin and the Ordos Basin have similar geological and structural settings,so the studies on typical basins will surely enrich and complete the theories on the intracratonic strikeeslip faults in domestic micro land blocks and multi-cycle basins and point out the direction for the discovery of more oil and gas resource.
