川东北宣汉—达县地区断裂系统及构造演化

FAULT SYSTEMS AND THEIR TECTONIC EVOLUTION IN XUANHAN-DAXIAN AREA, THE NORTHEASTERN SICHUAN BASIN

唐大卿 陈新军 张先平

Tang Daqing Chen Xinjun Zhang Xianping

中国地质大学, 资源学院, 武汉, 430074 2. 中国石油化工股份有限公司, 石油勘探开发研究院, 无锡石油地质研究所, 江苏, 无锡, 214151

China University of Geosciences, Wuhan, Hubei 430074, China 2. Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214151, China

断裂构造及相关褶皱是川东北宣汉—达县地区最重要和最典型的构造特征,对油气的早期运聚成藏和晚期调整改造均具有决定性意义.通过对约500 km2三维地震资料的精细解释,构建了宣汉—达县地区3套断裂系统,即志留系底部断裂系统、中构造层断裂系统和上构造层断裂系统,尤其后两者在本区意义重大.志留系底部断裂系统比较杂乱,可能与印支期构造运动有关;中构造层断裂系统发育强、规模大、继承性好,形成了该区主要目的层构造圈闭,该北东向断裂系统定型于燕山晚期并控制原生油藏的形成与保存;上构造层断裂系统形成于喜山早、晚2期,主体呈北西向并垂直叠加和改造中构造层断裂系统,对普光、毛坝场等地区的次生油气藏的形成、保存及后期改造具有重要作用.

Faults and fault related folds are the most important and typical structure in Xuanhan-Daxian area,the northeastern Sichuan Basin.They decided the primary reservoirs' preservation and the secondary reservoirs' reconstruction.Based on the detailed interpretation of about 500 km2 of 3-demension seismic data,the fault systems in Xuanhan-Daxian area have been divided into three systems:the fault system of Silurian bottom,the fault system of the middle structural stratigraphic and the fault system of the upper structural stratigraphic.The later two fault systems are the most important fault systems in this area.The fault system of Silurian bottom is very abnormal and it may be formatted in Indosinian Movements epoch.The fault system of the middle structural stratigraphic is the most important one in this area,it has good heredity and formatted the main structure traps in this area,the main system of NE direction formed in Yanshanian Movement epoch and controlled the primary reservoirs' formation and preservation.The fault system of the upper structural stratigraphic formed in the two periods of the early and later Himalayan Movement epoch.The main fault system in NW direction superposited on the fault system of the middle structural stratigraphic and reconstructed it in vertical direction.It also play a significant role in the secondary re-servoirs' formation,preservation and reconstruction in Puguang and Maoba chang areas.

国家重点基础研究发展计划(973计划)项目(2005CB422105)

https://doi.org/10.11781/sysydz200801058