塔里木北部库车地区的断层系统及其对油气的控制作用

库车地区发育逆冲推覆断层系、纵向走滑断层系、块断正断层系和横向走滑一逆冲断层系.沿非能干层的顺层滑脱断层极大地增强了非能干层的封盖能力.库车组沉积期末一西域组沉积期是逆冲推覆断层的主要活动期，也是气源岩的生排气和沿断层运移的高峰期；逆冲推覆断层在静止期起封闭作用.稍晚形成的纵向走滑断层和块断正断层因开启而成为油气运移的通道.库车地区北部，纵向走滑断层和块断正断层破坏油气藏；南部的塔北隆起，古近系膏盐岩层下发育的纵向走滑正断层控制了晚期次生油气藏的形成和分布.持续活动的横向走滑断裂主要起调节作用，造成东西方向地质的分段性和油气横向分布的差异性.库车地区"封存箱"的实质是断层构造封存，"封存箱"的顶、底板为非能十层及沿其发育的顺层断层，侧板为压（扭）性高角度逆冲断层和走滑断层.

Fault systems in Kuqa area,northern Tarim and its control to oil-gas accumulation

Based on geological and tectonic analyses,the fault systems in Kuqa area,northern Tarim were divided and its control to oil-gas accumulation was discussed.There were thrust-nappe system, longitudinal strike-slip system,normal block-faulting system and lateral (strike-slip)-thrust system.The interlayer-gliding fault occurred along incompetent beds and greatly enhanced the sealing capacity.The sedimentary period of the latest Kuqa Formation to Xiyu Formation was blossom period of thrusting,and of hydrocarbon generation and migration.The crealion of longitudinal strike-slipping and normal block-faulting was later than that of thrusts, which were open and acted as pathway of hydrocarbon migration.There was a lot of oil and gas seepage in northern Kuqa since the pools destructed by strike-slipping or normal faulting,while the secondary generated hydrocarbon reservoirs dominated in the Tabei(North Tarim)Uplift.The structural E-W segmentation and variation of hydrocarbon distributing in Kuqa area were constrained by transfer of the lateral strike-slipping.The nature of compartment in Kuqa area was a fault seal,with the bottom and top boundaries of compartment being incompetent beds and interlayer-gliding faults,and the lateral boundaries being high-angle thrusts or strike-slip faults.