川西南部上三叠统须二段低渗透砂岩储层裂缝分布的控制因素  

Controlling factors for fracture distribution in the low-permeability sandstone reservoir of the Second Member of the Upper Triassic Xujiahe Formation in the south of western Sichuan

作　　者：曾联波[1] 李跃纲[2] 张贵斌[3] 陈古明[2] 

机构地区：[1]中国石油大学石油天然气成藏机理教育部重点实验室,北京102249 [2]中国石油西南油气田分公司川西北气矿,四川江油621709 [3]中国石油大学资源与信息学院,北京102249

出　　处：《中国地质》2007年第4期622-627,共6页Geology in China

基　　金：石油科技中青年创新基金项目(05E7026)资助。

摘　　要：川西坳陷南部上三叠统须家河组二段低渗透砂岩储层发育有构造裂缝、成岩裂缝以及与异常高压有关的裂缝共3种类型,其中以构造裂缝为主。受印支期、燕山期和喜马拉雅期多期水平构造挤压、白垩纪深埋藏形成的异常流体压力以及新近纪以来的构造抬升剥蚀等造成的应力作用,该区主要形成有4组裂缝,其发育程度受岩性、层厚、构造部位、应力及流体压力等因素的控制。裂缝发育带主要沿南北向和北东—南西向构造带分布,在南北向构造带,近南北向裂缝和近东西向裂缝较其他两组裂缝更发育;而在北东向构造带,北东向裂缝和北西向裂缝较其他两组裂缝更发育。裂缝发育带控制了该区天然气的富集规律。There are tectonic fractures, diagenetic fractures and fractures related to overpressures in the low- permeability sandstone reservoir in the Second Member of the Upper Permian Xujiahe Formation in the south of the western Sichuan depression. Among them, tectonic fractures are dominant. Under the stresses resulting from horizontal tectonic compressions in the Indosinian, Yanshanian and Himalayan periods, overpressures formed by deep burial in the Cretaceous and tectonic uplift and erosion since the Neogene, four sets of fractures formed in the study area. The development degree of these fractures was controlled by the lithology, layer thickness, structural locations, stresses and fluid pressures. The zones of fractures are mainly distributed along the N-S and NE-SW-trending structural belts. In the N-S-trending structural belt, nearly N-S and nearly E-W sets of fractures are better developed than the other two sets of fractures; whereas in the NE-SW-trending structural belt, the NE-SW and NW-SE sets of fractures are better developed than the other two sets. The fracture development zones control the concentration of natural gas in the study area.

关 键 词：裂缝 控制因素 须二段 川西南部 

分 类 号：P618.13[天文地球—矿床学]