塔中地区断裂不同演化阶段对油气聚集的控制

塔中地区断层活动时间主要集中在加里东中晚期,海西期活动强度减小,喜马拉雅晚期很弱。主要断裂带在活动时代与期次、对沉积地层改造和建造的控制上以及上、下地层接触关系上存在明显不同。含油气断裂构造带油气聚集差异与断裂的阶段演化有着紧密的内在联系,体现在4个演化阶段的断层对油气聚集的差异控制上,即同沉积断裂控油气、沉积期后断裂控油气、主生烃期断裂控油气和成藏期后断裂控油气。

Control of faults at different evolution stages on hydrocarbon accumulation in Tazhong area,the Tarim Basin

An analysis of how faulting activities in different evolution stages control the hydrocarbon distribution and accumulation is carried out based on a summarization of the basic features of different faulted zones in the Tazhong area,Tarim Basin.The result shows that faults in the Tazhong area were most active during the Mid-Late Caledonian,softened during the Hercynian,and weak during the late Himalaya.It also indicates that the major fault zones are significantly different in the time and stages of activity,control on the formation and deformation of sedimentary formations and stratigraphic contact relationships between the upper and lower layers.The diffe-rences in hydrocarbon accumulation among different oil/gas-bearing faulted zones are closely related with the evolutionary stages of the faults,as being embodied in the differential control of faults at four evolutionary stages on hydrocarbon accumulation,namely syn-sedimentary fault,post-sedimentary fault,peak-hydrocarbon-generation-stage fault and post-hydrocarbon-accumulation fault.