【作者】 沈跃；

【导师】 王伟锋； 于正军；

【作者基本信息】 中国石油大学(华东) ， 地质工程（专业学位）， 2016， 硕士

【摘要】 隐性断裂带是指没有统一的断裂面、变形程度较弱的断裂带,是由区域应力场或基底断裂活动而产生于沉积盆地盖层中的弱变形构造带。由次级构造(小断层、裂缝带、洼陷、潜山、凸起、圈闭等)断续成带分布构成,属于断裂带形成演化早中期阶段的产物。研究表明,隐性断裂带在沉积盆地中普遍存在,并且与油气聚集关系密切,是未来油气勘探值得重视的领域。利用重力资料、地震资料、地质资料等手段,根据基底断裂分布、盖层断裂分布、沉积相砂体分布和油藏分布等特征,可在东营凹陷识别出9条北东、北西和近南北向的隐性断裂带,这些隐性断裂带在平面上通常表现为雁列状或帚状排列的次级断层带,部分表现为洼陷和凸起之间的构造突变带,或者是不同洼陷、不同构造单元之间的分界线。剖面上,隐性断裂带通常表现为花状构造、似花状构造、“Y”字形构造和帚状构造等具有走滑性质的构造样式。区域构造背景及东营凹陷的演化史表明,东营凹陷北东向的隐性断裂带形成于古近纪时期北东向基底断裂的右旋张扭运动,北西向的隐性断裂带形成于古近纪时期北西向基底断裂的左旋压扭运动,南北向的隐性断裂带形成于古近纪时期南北向基底断裂带的右旋走滑运动。以王家岗和八面河隐性断裂带为例,利用构造物理模拟实验研究了二者在形成机制上的差异。实验表明,八面河隐性断裂带形成于基底断裂30°以下的张扭运动,王家岗隐性断裂带形成于基底断裂30°~50°的张扭运动。通过对相关实验参数的提取,建立了基底断裂走滑量与盖层雁列式次级断层发育程度间的定量函数关系式,并利用公式反推出了王家岗和八面河隐性断裂带在古近纪各时期基底断裂的走滑位移量。东营凹陷隐性断裂带的控藏作用表现在以下三个方面:(1)影响了砂体的沉积,一定程度上控制了储集层的分布;(2)形成了大量的构造圈闭,同时,由于隐性断裂带控制了砂体的沉积,也会形成若干岩性圈闭和岩性—构造复合圈闭,大量发育的圈闭为油气聚集提供了有利的场所;(3)隐性断裂带上裂缝密集发育,有效的改善了储层物性。东营凹陷隐性断裂带的平面油气聚集模式有网格状聚集模式、雁列状断块聚集模式和带状断块聚集模式。根据不同方向隐性断裂带的剖面构造样式和油气富集规律,分别建立了东营凹陷北东、北西和南北向隐性断裂带的剖面控藏模式。更多还原

【Abstract】 Concealed fault zones are a type of weak deformation fault zone that form in sedimentary covers in the early-middle stage of their formation and evolution processes.They are consisted of regular secondary faults,reservoirs,facies,depressions and buried hills.They are difficult to be recognized because they are lack of discernible characteristics.Research shows that concealed fault zones are very common in sedimentary basins and are closely related to hydrocarbon accumulation.Nine concealed fault zones of NE-trending,NW-trending and SN-trending can be identified by basement rift,small dominant structure and sedimentary facies in Dongying depression.There are characterized by en-echelon secondary faults in the plane.Parts of them separate the sags and bulges,or different sags.In the section,concealed fault zones are characterized by flower structure,unobvious flower structure or ―Y‖-shaped structure.Regional structural background and evolution history of Dongying depression showed that the NE-trending concealed fault zones were formed by transtentional activities of NE-trending basement faults,while NW-trending concealed fault zones were formed by transpressional activities of NW-trending basement faults and the SN-trending concealed fault zone was formed by strike-slip activities of SN-trending basement fault.Set concealed fault zone Bamianhe and Wangjiagang as examples,studying their differences in formation mechanism by physical simulation experiments.Results showed that the concealed fault zone Wangjiagang was formed by 30°~50°transtentional activities of basement faults,while concealed fault zone Bamianhe was formed by transtentional activities of basement faults less than 30°.The quantitative functional relationship between strike-slip displacement of basement fault and development degree of secondary faults was set up by analyzed the experimental parameters.Based on the function,the strike-slip displacement of basement fault of concealed fault zone Wangjiagang and Bamianhe was calculated.The significance in hydrocarbon accumulation of concealed fault zones in Dongying depression represented in 3 aspects: First,they affected the distribution of sedimentary facies,which means they also affected the distribution of reservoir.Second,because of them,plenty of structural traps and lithologic traps are formed,which provided sufficient space for hydrocarbon accumulation.Third,the intensive fractures in concealed fault zones improved the porosity and permeability of reservoir.The planar patterns of hydrocarbon accumulation in concealed fault zones in Dongying depression are grid-shape composite pattern,en-echelon-shape fault block pattern and ribbon-shape fault block pattern.Based on the structural styles and hydrocarbon accumulation rules,section patterns of hydrocarbon accumulation in NE-trending concealed fault zones,NW-trending concealed fault zones and SN-trending concealed fault zone can be set up.更多还原