断裂带的结构特征及其对油气的输导和封堵性

Structural Characteristics of Faulting Zone and Its Ability in Transporting and Sealing Oil and Gas

断裂带是具有复杂结构的三维地质体,其内部可以划分为低渗透性的滑动破碎带、高渗透性的诱导裂缝带等具有不同物性特征的结构单元类型;受各种地质条件和因素的控制,不同性质及活动强度的断裂带、断裂的上下盘、同沉积断裂的不同深度,其断裂带内部结构特征存在差异,这导致了断裂具有对油气输导、封堵的双重性和时空差异:诱导裂缝带可成为油气运移的通道,而滑动破碎带则具有较强的横向分隔性;同沉积断裂下部对油气的横向封堵性要明显强于上部;断裂活动早中期对油气的输导性要强于晚期及断裂活动停滞期。精细刻画盆地内部断裂带内部结构特征对于分析断裂在油气运聚中所起的作用具有重要意义。

Faulting zone is a complex three-dimensional geological body with heterogeneous structures,the interior of which can be divided into different structural units with different properties,such as low-permeability slip damagezone,high-permeability induced fracture zone,and so on.Controlled by various geological conditions and factors,internal structures of faulting zones in different kinds and activity intensity faults,hanging wall and footwall,different depth of growth fault are different,which causes faults to have dual nature and temporal and spatial differences in transporting and sealing oil and gas：induced fracture zone can be the channel for transporting oil andgas,while slip damage zone has a strong horizontal segregation;oil and gas horizontal sealing of the lower part of growth fault is obviously stronger than the upper;oil and gas transport capacity of fault in early and middle faultactivity is much stronger than in late and resting stages.Therefore,understanding of internal structures of faulting zones in the basin has great significant in examining the role of faulting in the migration and accumulation of oil andgas.