走滑断层弯曲破碎带特征及对深部岩溶储集层发育的控制作用

Characteristics of Bend Damage Zones of Strike-Slip Faults and Its Control on Development of Deep Karst Reservoirs

为了提出断层弯曲破碎带概念,并探讨其对岩溶储集层发育的控制作用,调研了前人对断层破碎带的研究成果,以塔中北斜坡的三维地震数据体为基础,对断层弯曲破碎带进行识别,并利用均方根振幅属性等多种储集层预测技术对岩溶储集层进行预测。结果表明,断层弯曲破碎带是断层破碎带的一种重要类型,走滑断层破碎带可划分为端部、连接、弯曲、围岩4种破碎带类型。塔中ZG8-ZG11井区发育走滑断层弯曲破碎带,破碎带区域内奥陶系深部岩溶储集层发育。分析认为,弯曲破碎带内发育与主干走滑断层大角度相交的伴生断层,形成连通的网状断层系统,深部热液通过主干走滑断层进入网状断层系统,在埋藏溶蚀作用下围绕断层交叉区域形成优质岩溶储集层。综上所述,走滑断层弯曲破碎带对塔中深部岩溶储集层发育有控制作用。

In order to present concept of fault-bend damage zone,and to discuss the control of fault-bend damage zone on development of karst reservoirs,investigation of previous works on fault damage zones have been conducted.Meanwhile, based on 3D seismic data of North Slope of Tazhong Uplift,identification of fault bend damage zones and prediction of karst reservoirs by seismic attribute of root mean square amplitude,etc.have been processed.Our work shows that fault-bend damage zone is an important type of fault damage zones,which should be classified into tip-,linkage-,bend-and wall-damage zones.In ZG8-ZG1 1 wells area of Tazhong,fault-bend damage zones are developed with good karst reservoirs in the deep strata of Ordovician.The detailed mechanisms are as follows：In bend damage zones,related subsidiary faults mostly intersected with master strike-slip faults at high angles,allowing the formation of connecting faults network;hydro-thermal fluids migrated along master strike-slip faults and penetrated into faults network,which generated deep-buried good karst reservoirs of the Ordovician surrounding faults intersection areas by burial dissolution.In general,the bend damage zones of strike-slip faults have important controls on the development of deep karst reservoirs in Tazhong.