正牵引构造形成过程的物理模拟及其油气勘探意义:以克-百断裂带为例  

Physical Modeling of Normal Drag Structure and Its Significance in Petroleum Exploration:A Case Study in Ke-Bai Fault Belt,China

作　　者：熊连桥[1,2] 于福生[3] 姚根顺 安源[3] 赵进雍[4] 

机构地区：[1]中国石油勘探开发研究院 [2]中国石油杭州地质研究院 [3]中国石油大学(北京)地球科学学院 [4]中国石油新疆油田分公司勘探开发研究院

出　　处：《高校地质学报》2017年第1期125-133,共9页Geological Journal of China Universities

基　　金：国家自然科学基金项目(41372116);中国石油集团科技重大专项(2014E-32-09)联合资助

摘　　要：长期以来牵引构造被视为油气勘探的重点领域,随着构造沉积学的发展,同沉积逆牵引构造已经取得了大量的进展,但是对正牵引构造的研究还比较少,使其成为了研究热点。关于克-百断裂带的构造成因机制尚还存在争论,与正牵引构造相关的物理模拟在国内尚未见报道。本文通过地震解释资料描述了准噶尔盆地西北缘克-百断裂带正牵引构造的变形特征,结合应力场分析,讨论了正牵引构造的成因机制;并设计物理模型对正牵引构造的形成演化进行了模拟,给出了克-百断裂带为挤压成因的新论据。研究认为,克-百断裂带的正牵引构造是在印支期、燕山期挤压推覆过程中形成的,属于同生逆断层体系;塑性地层的发育是正牵引构造产生的前提;随着前冲断层倾角变大,断层活动性减弱,为断层上盘地层收缩形成正牵引构造创造了条件。此次研究提出正牵引构造的形成演化模式分为三个阶段:第一阶段为褶皱轴面紧贴断层面的雏形阶段;第二阶段为褶皱轴面旋转,规模扩展阶段;第三阶段为继承性同沉积阶段。结合前人研究成果,认为同生逆断层可作为油气运移通道,但是正牵引构造的高部位并不一定是有利的油气聚集区;正牵引构造第一阶段形成的底形控制了砂体的展布,在第二阶段,构造低部位能形成岩性油气藏;而正牵引构造发育的第三阶段,可在构造高部位形成构造或地层圈闭油气藏。Fault drag has long been recognized as an important hydrocarbon exploration field. With the development of tectonic sedimentology,great achievements have been made in understanding of the contemporaneous reverse drag structures. However,studies on normal drag structures are relatively rare,which makes it a research subject. The structure formation mechanism of the Ke-Bai Fault Belt in this study area is still in debate,and the relevant physical modeling of the structures has not yet been carried out. This paper described the deformation characteristics of the normal drag structures developed in the Ke-Bai fault belt,Junggal Basin,China,and discussed its formation mechanism on the basis of stress field analysis. Evolution of the normal drags was simulated with physical experiments,which provided the new evidence of compressional theory for Ke-Bai fault belt. The study shows that the normal drags ofthe Ke-Bai fault belt was formed in the compress process during the Indosinian-Yanshanian periods,and it belongs to a contemporaneous thrust fault system. Development of plastic formation is a premise of the formation of normal drag structure. The activeness of faults decreased with the increase of fault angle,which is favorable for the hanging wall shrinkage and accordingly,the formation of normal drags. The paper proposed that evolution of the normal drags in the study area can be divided into three stages：（1） Prototype stage,where the fold axial plane was parallel to the fault plane;（2） Development stage,where the fold axial plane rotated apart from the fault plane and the scale of the fold extended; and （3） Inherited contemporaneous sedimentary stage. Combined with previous studies,this paper shows that the contemporaneous thrust faults in the study area could be the migration paths of hydrocarbon,while the structural highs of the normal drags may not be the favorable reservoirs. Bed form formed by normal drags controlled the distribution of sand bodies. Lithologic reservoirs can be formed at the lower

关 键 词：正牵引构造 演化模式 物理模拟 油气藏类型 克-百断裂带 

分 类 号：P618.130.2[天文地球—矿床学]