鄂尔多斯盆地上古生界气藏与深盆气藏特征对比

Comparison between the Upper Paleozoic gas reservoirs in Ordos Basin and deep basin gas reservoirs

李仲东 郝蜀民 李良 惠宽洋 过敏

Li Zhongdong Hao Shuming Li Liang Xi Kuanyang Guo Min

通过对鄂尔多斯盆地上古生界砂泥岩压实资料、孔隙演化、压力成因、气水分布、天然气运移和成藏特征等分析研究,结合前人的成果资料,对上古生界气藏与典型深盆气藏特征进行了详细对比。研究认为,如果仅从成藏基本条件和气藏某些表现形式看,上古生界气藏与深盆气藏有相似之处。但开发动态资料显示,气层连通性差,气层分属多个压力系统,并没有出现大范围的气水关系倒置现象,局部存在边底水,气水分布主要受构造部位和有利储层相带等因素控制。由成藏作用过程、成藏关键条件和成藏机理考察,上古生界气藏具就近运移、聚集、成藏特点,主要属岩性气藏或构造-岩性气藏。综合分析认为,储层连通性差、圈闭受岩性和构造控制是造成上古生界气藏有别于深盆气藏的根本原因。

A comparison between the Upper Paleozoic gas reservoirs in Ordos Basin and typical deep basin gas reservoirs was carried out through analysis of sandstone and shale compaction,pore evolution,pressure forming mechanism,gas and water distribution,gas migration and accumulation,pooling characteristics,as well as previous research results.These two kinds of gas reservoirs show some similarities in terms of basic pooling conditions and certain manifestations.However,dynamic data from gas development indicate that the Upper Paleozoic gas reservoirs are characterized by poor connectivity of gas layers,multiple pressure systems,no extensive inversion of gas-water contact,the existence of local edge water,and the control of structure location and favorable reservoir facies belts on gas-water distribution.A research on process,key conditions,and mechanisms of hydrocarbon pooling suggests that the Upper Paleozoic gas reservoirs belong to lithologic or structural-lithologic gas reservoirs featuring in near-source migration,accumulation,and pooling.It is therefore concluded that the Upper Paleozoic gas reservoirs distinguish themselves from deep basin gas reservoirs by poor connectivity of reservoirs and control of lithology and structure on traps.

10.11743/ogg20090204