摘要
张巨河地区是黄骅坳陷东部滩海地区油气勘探的重点区 ,北西西走向的张东断层和北东走向的张北断层是该区的二级断层。张东断层平面呈锯齿状 ,可大致分为两段 ,断层落差具分段性 ,且平面位移从早到晚总体变小 ,断面呈座椅状 ,断面的中部缓倾段对应以泥岩为主的东营组二段 ,表明断层折射现象与岩性密切相关 ,下第三系之下能干性强的中生界或潜山也应起重要作用。张巨河地区的三级断层属盖层断层 ,与基岩构造脱耦 ,总体走向为北东东向 ,反映了区域性北北西 南南东向拉张应力的作用 ,而张北断层、张东断层与最小主应力方向交角皆超过 5 0° ,应属张性断层。张东断层西段相对不利于油气运聚 。
The Zhangdong fault, located in the east of Huanghua depression, is NWW striking, zigzag shape in the plane and steeply dipping at the top and the bottom as well as slightly dipping at the medium of the fault in the profile. The throw of Zhangdong fault appears segmentation, and its horizontal displacement decreases from the earlier to the later. Geometrical shape of the fault likes chair shaped. Its slight dipping part is concordant to the strata of Dongying Formation especially to the second member consisting of mudstone. The shape of the fault is controlled not only by this factor but also by competent basement or buried hill. Third order faults near the Zhangdong fault belong to the cover faults with NEE striking and decouple with the basement structure, this reflects they are controlled by regional NNW SSE extension. The angles between the earlier NE striking Zhangbei fault or NWW striking Zhangdong fault and minimum stress direction are more than 50°, so both faults are extensional normal faults. According to the feature and historical activities, the Zhangdong fault is divided into two segments and the structural feature of the west segment is not of benefit to oil gas migration not like that of the east segment, especially the central of the west segment is perhaps a barrier of oil gas migration.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2002年第6期38-40,共3页
Petroleum Exploration and Development
关键词
黄骅坳陷
断层
分段性
拉张
脱耦
Huanghua depression, fault, segmentation, extension, decoupling
