摘要
中央断裂带位于中国东部东营凹陷中部 ,发育有厚达 70 0 0 m的第三系碎屑岩。主要勘探目的层是第三系的沙河街组地层。影响中央断裂带的主要地质力学因素有三个方面 :(1 )脊部塌陷机制 :由东营凹陷北部的埕南大断裂 (犁式张性断裂 )所控制的凹陷中部地堑型断裂 ;(2 )塑性物质上隆机制 :中央断裂带深部存在盐体上隆 ;(3)右旋张扭机制。这些机制在时间上不是孤立的 ,而是相互作用的。区域构造、沉积作用和右旋张扭应力控制了脊部塌陷 ,而右旋张扭又与塑性盐体上隆产生的拉张有关。因此 ,中央断裂带的形成是这三种机制在时间上和空间上复合叠加作用的结果。该文对中央断裂带西部的现河庄油田的地震剖面进行了综合解释 ,研究了断裂体系的动力学特征和构造演化模型 ,认为中央断裂带的形成演化经历了四个演化阶段 :初期凹陷阶段、早期拱张阶段、中期断陷阶段和晚期稳定阶段。根据中央断裂带的地质、沉积、构造模型和演化的综合研究 ,探讨了断裂带的生、储、盖组合等油气体系 ,指出了油气勘探的重要领域为高断块。
The Central Fault Belt is located in the Dongying depression of East China. The Tertiary clastic rocks over 7 000 m in thickness occur. The main exploration target is the Tertiary Shahejie Group. There are three major geomechanical controlling factors of the fault belt: (1) The origin of the crestal collapse grabens for a faulted depression controlled by a listrical Chennan fault, bounding the depression on the north. (2) Origin of extension by uplifting of the plastic materials , such as salt dome beneath the central belt. (3) The origin of the NNW SSE tensile force associated with the regional dextral tensile shearing stress field. These origins are likely interdependent and are not isolated in time. The crestal collapse grabens were controlled not only by the regional structure and sedimentation, but also by the dextral tensile shearing forces. Meanwhile, it was associated with the upper bending of the Tertiary strata caused by the uplifting of the salt body. Therefore, the formation of the Central Fault Belt is a synthetic result by stacking all the geomechanical factors in time and space, including the crestal collapse grabens, the uplifting of the plastic body and the regional dextral tenso shearing stress force. Seismic profiles across the Xianhezhuang oilfield, the western part of the Central Fault Belt, are interpreted. The kinematics characteristics of the fault system are studied from the structural restoration models based upon the seismic sections. Four evolution stages of the Central Fault Belt can be recognized and described. They are the primitive depression stage, early uplifting and faulting stage, middle fault depression stage and late stable stage. Based on the analysis of the geology, sedimentation, structure pattern and evolution, the petroleum system of the fault belt is studied by discussing the combination of the source rocks, reservoirs and cap rocks, together with the types of the traps. The paper points out that the faulted closed highs, lithology traps and the targets in the deep associated with salt dome are the most important areas for oil exploration.
出处
《成都理工学院学报》
CSCD
2000年第4期359-367,共9页
Journal of Chengdu University of Technology
基金
"油气藏地质及开发工程"国家重点实验室资助项目! (PL C990 4 )
关键词
演化机制
断裂带
盐体
第三系
东营凹陷
evolution mechanism
fault belt
salt body
Tertiary
Dongying depression
Bohai gulf basin
East China
