四川盆地高石梯—磨溪地区走滑断层构造特征与天然气成藏意义  

Strike-slip faults and their significance for hydrocarbon accumulation in Gaoshiti–Moxi area, Sichuan Basin, SW China

作　　者：马德波 汪泽成[2] 段书府[2] 高建荣[2] 江青春[2] 姜华[2] 曾富英[2] 鲁卫华[2] MA Debo;WANG Zecheng;DUAN Shufu;GAO Jianrong;JIANG Qingchun;JIANG Hua;ZENG Fuying;LU Weihua(China University of Geosciences,Beijing 100083,China;Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China)

机构地区：[1]中国地质大学(北京),北京100083 [2]中国石油勘探开发研究院,北京100083

出　　处：《石油勘探与开发》2018年第5期795-805,共11页Petroleum Exploration and Development

基　　金：国家科技重大专项"下古生界-前寒武系碳酸盐岩油气成藏规律;关键技术与目标评价"(2016ZX05004-001)

摘　　要：基于四川盆地中部高石梯—磨溪地区连片三维地震资料和钻井资料,利用断层构造解析方法,分析研究区走滑断层的构造特征与形成演化及其对天然气成藏的意义。结果表明:(1)研究区古生界发育张扭性走滑断层,剖面上发育高陡直立、花状构造、"Y"字形与反"Y"字形3种构造样式。平面上寒武系发育近东西向、北西向、北东向3组断层,呈线状延伸,整条断层由多条呈斜列状展布的次级断层组成;二叠系以近东西、北西向断层为主,分布在研究区中东部,且具有北多南少的特点。(2)近东西向、北西向断层为右行走滑断层,北东向断层为左行走滑断层。近东西向断层的走滑作用强,最大水平位移量约550 m,北东向断层的走滑作用弱。寒武系断层的活动强度强于二叠系断层。(3)走滑断层经历早加里东期、晚海西期2期活动,为2期地裂背景下先存构造薄弱带受到斜向拉张所致,主干断层具有一定的继承性。(4)走滑断层及周围裂缝提升了寒武系龙王庙组储集层的孔隙度和渗透率,控制着二叠系栖霞组—茅口组岩溶储集层的分布,形成了该区多层系含气的局面。Based on the three dimensional seismic data and drilling data in Gaoshiti–Moxi area,the structural characteristics and evolution process of strike-slip faults in the study area and their significance for gas accumulation were examined using the method of fault structure analysis.The results show that:(1)Transtensional strike-slip faults are developed in the Paleozoic in study area.On the profile,there are three types of structural styles:steep and erect,flower structures,'Y'and reversed'Y'type faults.On the plane,strike-slip faults developed in the Cambrian extending linearly and along the nearly EW,NW and NE direction.The faults are composed of multiple secondary faults in en-echelon arrangement;faults in the Permian are mainly along nearly EW and NW direction,and the Permian faults are distributed in the middle east part of the study area and they are more in the north than in the south.(2)The nearly EW and NW trending faults are dextral strike-slip faults,and the NE trending faults are sinistral strike-slip faults.The strike-slip strength of the nearly EW trending faults are the strongest and the maximum horizontal displacement is 550 m,while the strike-slip strength of the NE trending faults is the weakest.The Cambrian faults had stronger activities than the Permian faults.(3)The transtensional strike-slip faults were active in two periods,the early Caledonian period and the late Hercynian period,and were the products of sideway extension of pre-existent weak zones in Xingkai and Emei taphrogenesis,with certain inheritance in the main parts.(4)The strike-slip faults and surrounding fractures enhance the porosity and permeability of the reservoir in Cambrian Longwangmiao Formation and control the distribution of karst reservoirs in the Permian Qixia-Maokou Formation,bringing about the situation of multiple gases bearing series in this area.

关 键 词：四川盆地 高石梯-磨溪地区 寒武系 二叠系 走滑断层 构造特征 天然气成藏 

分 类 号：TE122.2[石油与天然气工程—油气勘探]