摘要
鄂尔多斯盆地塔巴庙地区上古生界石炭系、二叠系中发育6套含气层,其中最具经济价值的天然气高产层主要发育于下石盒子组上部盒2+3段。其岩相主要为三角洲平原内辫状河-曲流河沉积体系中的块状砾岩相、含砾粗砂岩相,砂岩的储层物性与粒度呈正相关关系。这种高产气层具有特征的电性反应,表现为自然伽马值低、自然电位显著负异常、电阻率高;物性方面,孔隙度>8%、渗透率>0.8 mD,pc50<2 MPa,r50>0.4μm。储集砂岩常侧向相变大或尖灭于泥岩之中,上覆巨厚的区域性泥岩盖层,形成良好的侧向遮挡与纵向封盖,为天然气富集创造了条件。
In Tabamiao area of Ordos basin, the commercial prolific gas reservoirs mostly exist in the top interval of the Xiashihezi Formation （P1 x^2＋3）. The lithofacies of the reservoir mainly consists of massive conglomerate and pebbled gritstone. They have deposited in braided-meander river, usually changed to poststone and/or siltstone or pinchouted into mudstone and been covered with thick mudstone, so the reservoirs have been sealed laterally and vertically. The log response of the gas reservoir is characterised by low gamma ray, self-potential reduction and high resistivity. The petrophysics of the gas reservoir is characterised by porosity〉8%, permeability〉0.8 mD, pc50 〈2 MPa and r50〉0. 4 μm.
出处
《成都理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2005年第6期604-608,共5页
Journal of Chengdu University of Technology: Science & Technology Edition
