鄂尔多斯盆地非构造气藏类型

鄂尔多斯盆地非构造气藏可分为4类:砂岩透镜体岩性圈闭、差异成岩作用形成的岩性圈闭、上倾岩性-地层圈闭、与风化壳和不整合面有关的岩性-地层圈闭气藏.非构造气藏分布受生烃坳陷和高效储集层分布制约,常位于气源岩与高效储集层的叠合部位、隆起与坳陷的转换部位.位于晋西挠褶带和天环坳陷间的伊陕斜坡区,因具有构造变形微弱,上、下古生界生烃中心叠置,高效储层发育,储集层物性侧向变化快等特点,具备形成非构造圈闭优越条件,为盆地气藏勘探的重点区带.

Type of Nonstructural Gas Reservoirs in Ordos Basin

The non-structural gas reservoirs in Ordos Basin can be divided into 4 types,such as a reservoir of lithologic trap of sandstone lens,lithologic trap of differential diagenesis,overlying lithologic-formation trap and the reservoir related with weathering and uncomformity surface.The distribution of non-structural gas reservoir is constrained by hydrocarbon generating depression and the distribution of high efficient reservoir,the non-structural gas reservoir is often located in a coincident position of the high efficient reservoir and in the crossover of uplift with depression.The reservoir is located at Yishan slope area between Jinxi fold belt and Tianhuan Depression,it has the characters of less structural deformation,overlying hydrocarbon genetic center in upper and lower Palaeozoic era,growth of high efficient reservoirs and as well as fast lateral changes of reservoir physical properties,it has the condition of forming non-structural traps,which is the major area for gas reservoir exploration in the basin.