塔中隆起两组走滑断裂对岩溶储层发育的控制机制  

Controlling mechanism of two strike-slip fault groups on the development of the Ordovician karst reservoirs in the Tazhong Uplift,Tarim Basin

作　　者：张艳萍[1] 吕修祥[2,3] 于红枫[4] 敬兵[4] 张春林[1] 蔡俊[1] 

机构地区：[1]中国石油大学(北京),北京102249 [2]中国石油大学(北京)地球科学学院,北京102249 [3]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [4]中国石油塔里木油田分公司勘探开发研究院,新疆库尔勒841000

出　　处：《石油与天然气地质》2016年第5期663-673,共11页Oil & Gas Geology

基　　金：国家重点基础研究发展规划(973计划)项目(2012CB214804);国家自然科学基金项目(41372146;41572100)

摘　　要：走滑断裂对塔中隆起岩溶储层发育的控制机制一直缺乏深入研究。采用均方根振幅属性,对塔里木盆地塔中北斜坡奥陶系浅、中、深部的岩溶储层进行预测,发现大量岩溶储层继承性分布于北西向和北东向断裂所夹持块体的东北和西南角区域,特别是中古5和中古10块体的深层奥陶系尤为明显。沉积相和古地貌等无法解释这种现象,走滑断裂活动可提供合理解释:北西向断裂的右旋压扭,诱发北东向断裂的左旋走滑,断裂之间的块体的东北和西南角位于北西向和北东向走滑断裂的交汇区,断裂诱发的裂缝带交错发育;而断裂的走滑运动导致其东北和西南角形成局部拉张区、西北和东南角形成局部挤压区,岩石的抗拉强度远小于抗压强度,故拉张区极易拉张破裂成缝。裂缝提供溶蚀流体运移通道,也增加流体与岩石的接触面积,故走滑断裂夹持块体的东北角和西南角岩溶储层发育,表明走滑断裂是塔中岩溶储层发育的控制因素之一。Controlling mechanisms of strike-slip faults on development of the Ordovician karst reservoirs in the Tazhong Uplift,Tarim Basin are poorly understood.Seismic attribute of root mean square amplitude was used to predict karst reservoir distribution in the shallow,middle and deep Ordovician on the North Slope of Tazhong Uplift.The results show that most of the karst reservoirs distribute with inheritance in the northeastern and southwestern ends of blocks which are bounded by the NW- and NE-trending faults,especially the deep Ordovician in ZG5 and ZG10 blocks.Such distribution characteristics cannot be interpreted by sedimentary facies and palaeogeomorphology,while strike-slip fault activity could provide a possible interpretation：Right-lateral compress-shear activity of the NW-trending faults induces left-lateral strike-slip activity of the NE-trending faults.The northeastern and southwestern ends of blocks bounded by the NW- and NE-trending faults are located in the intersection area of the NW- and NE-trending faults,where crossed fracture zones induced by faults are well developed.In addition,the strike-slip movements led to local extension in the northeastern and southwestern ends of blocks,while local compression in the northwestern and southeastern ends.Extensional fracturing of rock in local extension area is much easier than compressional fracturing of rock in local compression area for that the tensile strength of rock is much smaller than its compressive strength.The extensional fractures provide migration pathway to dissolution fluid and increases contact area of dissolution fluid and rock,so the northeastern and southwestern ends of blocks have well developed karst reservoirs.The research suggests that the strike-slip fault is one of controlling factors on development of karst reservoirs in the Tazhong Uplift.

关 键 词：走滑断裂 岩溶储层 碳酸盐岩 奥陶系 塔中隆起 

分 类 号：TE121.2[石油与天然气工程—油气勘探]