鄂尔多斯盆地塔巴庙地区二叠系下石盒子组盒1段砂岩成岩相与储集性能关系

塔巴庙地区下石盒子组盒1段发育了辫状河道相沉积,砂体厚度10~60 m,横向上连片,分布较稳定。勘探证实,盒1段砂岩非均质性较强、含气性呈局部分布、不连片,圈闭类型为岩性圈闭气藏。根据薄片、铸体薄片、X衍射、扫描电镜及压汞分析等资料对盒1段砂岩进行微观分析,了解其自生矿物类型、成岩作用及成岩序列、孔隙演化特征和孔隙发育的影响因素,进而分析胶结物组合类型及其对储集性能影响关系。认为以胶结物主要组合类型进行盒1段砂岩成岩相划分,结合录井油气显示、试气和测井等资料分析各成岩相储集性能、含气性和测井曲线上反映特征,找出有利的成岩相,以此在平面上预测盒1段砂岩天然气富集有利区,为勘探寻找天然气富集区提供依据。

Diagenetic Facies and Reservoir Capability of p1x1 Sandstone in Tabamiao Area of Ordos Basin

The Tabamiao Area grows the braided river facies in p~1_(x1) period,in which sandstone thickness is from ten to sixty meters,and distribution has the feature of the stronger heterogeny,the lateral continuity and stability.Exploration proved it is local and discontinuous for hydrocarbon content distribution of p~1_(x1) sandstone and the trap type belongs to the lithologic trap.According to the lab data of thin-section,cast thin-section,X-ray diffraction and injection,p~1_(x1) sandstone is known in some hands of self-reproducing mineral type,diagenesis and diagenetic sequence,pore evoluting feature and growing controlled factor.And then analysis is carried out on the main combination type of cement favorably growing pore in relation to which affects reservoir capability of the sandstone.The diagenetic facies of p~1_(x1) sandstone is sorted in terms of the cement combination type,which is analyzed on some sides of reservoir capability,pore growing situation,hydrocarbon content,and log reflection character from log hydrocarbon showings,testing and log data,so the favorable diagenetic facies of p~1_(x1) sandstone is found to forecast the favorable accumulation area of p~1_(x1) sandstone in the plane and offer the evidence of the proving p~1_(x1) gas accumulation.