摘要
靖边气田碳酸盐岩储层次生溶蚀孔洞缝成层连片发育,古岩溶对孔洞缝的形成至关重要。利用岩心观察、薄片鉴定及多种测试资料,研究了储层古岩溶特征及其控制因素,进而探讨了古岩溶对气藏的控制机制。①靖边气田储层经历过同沉积-间歇性暴露环境下的层间岩溶、表生-大气淡水淋滤环境下的风化岩溶和埋藏-压释酸性水环境下的缝洞系岩溶等3期岩溶;②Ⅰ期岩溶受沉积环境控制、Ⅱ期岩溶受前石炭纪古地貌控制、Ⅲ期岩溶受主排烃期古构造控制;③多期岩溶选择性叠加控制了气藏分布;④马五11-五31气藏是(Ⅰ+Ⅱ+Ⅲ)期岩溶叠加的结果,受云坪微相、台丘-斜坡地貌和成藏期局部鼻隆构造等地质因素控制;马五41气藏是(Ⅰ+Ⅲ)期岩溶叠加的产物,受云坪微相和成藏期局部鼻隆构造控制。
Secondary holes, caverns and fractures are developed in carbonate reservoirs of Jingbian gasfield, and Ordovician palaeokarst is very important for the forming of secondary holes, caverns and fractures. The palaeokarst features and its controlling factors are researched and the controlling mechanism of palaeokarst on reservoirs are furtherdiscussed by use of the core observation data, thin section analysis data and various well test data. The results indicatethat the reservoirs in Jingbian gasfield experienced three periods of karst consisting of interstratal karst under the environment of syndeposition-intermittent exposure, weathering crust karst and fracture-cavern system karst. The firstperiod of palaeokarst is controlled by the sedimentary environment, the second period of palaeokarst is controlled bythe pre-Carboniferous palaeogeomorphology and the thirdperiod of palaeokarst is under the control of paleostructure;multi-stage palaeokarst controls the distribution of gas reservoirs; M511-531 gas reservoir is the product of the superposition of multiphase palaeokarst (Ⅰ+Ⅱ+Ⅲ), while M541gas reservoir is the product of the superposition of (Ⅰ+Ⅲ)palaeokarst which is controlled by the sedimentary microfa-cies and local nose lifting structure.
出处
《石油地质与工程》
CAS
2011年第1期1-4,141,共4页
Petroleum Geology and Engineering
基金
国家重大专项"复杂油气田地质与提高采收率技术"(2008ZX05009-004-03)
关键词
控藏机制
古岩溶
碳酸盐岩
靖边气田
鄂尔多斯盆地
reservoir-controlling mechanisms
palaeokarst
carbonate rock
Jingbian gasfield
Ordos basin
