摘要
目前对于中扬子地区强烈叠加改造区当阳复向斜断裂系统的分布规律和成因机制认识不清,制约了该区上奥陶统五峰组—下志留统龙马溪组页岩气勘探开发的进程。为了厘清该区断裂系统的分布规律和成因机制,揭示不同成因断裂对页岩气保存条件影响作用的差异,以该地区巡检斜坡区块的三维地震资料为基础,应用前陆逆冲理论和里德尔剪切模式,系统解析了巡检斜坡区块断裂特征和形成机制,进而探讨了当阳复向斜断裂对五峰组—龙马溪组页岩气保存条件的影响。研究结果表明:①巡检斜坡区块断裂系统纵向上划分为深层、中层、浅层3套系统,平面上分为3个区块,其中主控断裂FA、FB断裂带处于走滑断层发育初期—早期阶段;②中燕山期北东东向挤压、南东向右旋压扭和晚燕山期近东西向左旋张扭应力场形成了区内逆冲构造体系、压扭构造体系、张扭构造体系等3个断裂体系;③燕山期以来强烈走滑变形改造对龙马溪组页岩气后期保存条件产生了严重的破坏作用,其中逆冲断层、R'面断层及FB断裂东段对页岩气保存条件的破坏相对较弱,有利于页岩气的保存。
The distribution laws and formation mechanisms of the fault system of Dangyang synclinorium in the intensely superimposed reworked zone of Middle Yangtze area have not been understood clearly,which restricts the exploration and development process of the Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation shale gas in this area.In order to clarify the distribution laws and formation mechanisms of the fault system in this area and reveal the difference in the influence of the fault of different genesis on the preservation condition of shale gas,this paper systematically analyzes the characteristics and formation mechanisms of the fault in the Xunjian slope block by using the foreland thrust theory and the Riedel shear model,based on the seismic data of this block.In addition,the influence of the fault system of Dangyang synclinorium on the preservation condition of Wufeng Formation-Longmaxi Formation shale gas is discussed.And the following research results are obtained.First,the fault system in the Xunjian slope block can be divided into three systems vertically(i.e.,deep,medium and shallow)and three blocks areally.The main control faults,namely FA and FB fault zone,are in the initial and early development stage of strike slip fault.Second,under the action of the NEE compression and SE compression-torsion stress fields during Middle Yanshanian and the nearly EW left-lateral tension-torsion stress field during Late Yanshanian,three fault systems are formed in the study area,i.e.,thrust structure system,compression-torsion structure system,and tension-torsion structure system.Third,the strong strike slip deformation reworking since the Yanshanian brings significant damage to the preservation condition of Longmaxi Formation shale gas in the late stage,but the thrust fault,the R'plane fault and the east section of FB fault have weak damage to the preservation condition of shale gas and are favorable for the preservation of shale gas.
作者
何勇
张东涛
栗维民
张介辉
姚秋昌
张文萍
牛卫涛
梅珏
HE Yong;ZHANG Dongtao;LI Weimin;ZHANG Jiehui;YAO Qiuchang;ZHANG Wenping;NIU Weitao;MEI Jue(PetroChina Zhejiang Oilfield Company,Hangzhou,Zhejiang 311100,China;Geological Research Institute,BGP Inc.,CNPC,Zhuozhou,Hebei 072750,China)
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2021年第9期1-11,共11页
Natural Gas Industry
基金
中国石油天然气集团有限公司重大现场试验项目“深层页岩气有效开采关键技术攻关与试验”(编号:2019F-31)。
关键词
中扬子地区
强烈改造
当阳复向斜
断裂体系
里德尔剪切
页岩气保存
Middle Yangtze area
Intensely reworked
Dangyang synclinorium
Fault system
Riedel shear
Shale gas preservation
作者简介
何勇,1967年生,正高级工程师,主要从事常规与非常规油气地质工程一体化综合评价、勘探开发规划部署等工作。地址:(310023)浙江省杭州市余杭区五常街道荆山湾路。ORCID:0000-0002-0169-9584。E-mail:hey85@petrochina.com.cn;通信作者:张东涛,1987年生,工程师,硕士,主要从事页岩气地质综合评价研究工作。地址:(310023)浙江省杭州市余杭区五常街道荆山湾路。ORCID:0000-0003-0964-5203。E-mail:zhangdt85@petrochina.com.cn。
