地质学报2018，Vol.92Issue(1)：184-196,13.
东海盆地西湖凹陷中西部低渗近致密—致密砂岩气成因、来源及运聚成藏
Genesis, Origin and Migration-Accumulation of Low-Permeable and Nearly Tight-Tight Sandstone Gas in the Central Western Part of Xihu Sag, East China Sea Basin
摘要
Abstract
With middle-lower Pinghu and Baoshi formations in western slope zone and lower Huagang formation in western sub-sag in Xihu Sag,East China Sea Basin as the objectives,this study describes the macro and micro distribution characteristics of low-permeable and nearly tight-tight sandstone gas reservoirs using drilling data,confocal laser scanning microscope and scanning electron microscope.Based on tectonicsedimentary settings,stable carbon isotopic compositions of natural gas and analysis result of light hydrocarbon,this study carried out comprehensive analysis of genesis,origin and migration-accumulation of tight sandstone gas using source rock simulation and fluid inclusion technology.The results indicate that nearly tight-tight sandstone gas in two study regions is mainly coal-type gas.Tight sandstone gas in western sub-sag mainly comes from coal-measure rocks in the Pinghu Formation,and dark sapropelic matter may indicate existence of minor amount of oil-type gas.In addition,part of natural gas may be slightly affected by coal-measure rock of the lower Huagang Formation.Nearly tight sandstone gas in western slope zone can be divided into two groups:moderately mature gas from local source rocks and mature late stage-highly mature gas from source rocks in western sub-sag.The mature late stage-highly mature gas in western sub-sag vertically migrated and accumulated via faults at 3.9 ～0 Ma.Moderately mature gas was injected into reservoirs in western slope zone at 2.8～0 Ma.Meanwhile,the mature late stage-highly mature gas from western sub-sag migrated into western slope zone via ladder-like channel which consists of faults and deltaic front channel sand bar.关键词
成藏/成因气源/西湖凹陷/致密砂岩气Key words
accumulation/origin/Xihu sag/tight sandstone gas引用本文复制引用
苏奥,陈红汉,吴悠,雷明珠,李倩,王存武..东海盆地西湖凹陷中西部低渗近致密—致密砂岩气成因、来源及运聚成藏[J].地质学报,2018,92(1):184-196,13.基金项目
本文为国家重大科技专项(编号2011ZX05023-004-010)和国家自然科学基金项目(编号41202088)联合资助的成果. （编号2011ZX05023-004-010）
