苏码头构造须二段储集层特征及勘探方向

Reservoir Characteristics and Exploration Direction of Xujiahe 2 Member, Sumatou Structure

川西南部地区是上三叠统的生烃中心,具有良好的生油气条件,须二段是该地区天然气的重点勘探开发层位,龙门山山前带已获得平落坝、邛西等多个气田及含气构造,而低缓构造带须家河组勘探未获得大的突破。利用岩屑录井、岩心、岩屑薄片及压汞等资料,对苏码头构造须二段的储层岩石学特征、储集空间类型、成岩作用类型及孔隙结构等进行了分析。结果表明:须二段储层砂岩以中粒为主,成分成熟度较高,结构成熟度中等,储集空间以粒内溶孔为主,具有小孔细喉特征,储集条件优于平落坝、邛西等构造。苏码头构造须二段尤其是码1断层下盘具有较大的勘探潜力。

The south area of western Sichuan Basin is an upper Triassic hydrocarbon- generating center with better conditions to generate oil and gas. Xujiahe 2 Member is just an important exploration and development zone in this area. In the frontal Longmengshan Mountain, both Pingluoba and Qiongxi gasfields, and a few oilbearing structures, have been discovered. But, the Xujiahe Formation in some gentle structure belts has not made an exploration breakthrough. Based on some data from mud logging, core, thin section, and mercury injection, the Xujiahe 2 Member of Sumatou structure was analyzed in terms of its reservoir characteristics,space type, diagenesis, and porous structure. Results show that(1)this reservoir is dominated by middle-sized sandstone with a higher component maturity and a middle texture maturity;(2) its space is mainly composed of intragranular dissolution pore with small pore and fine throat;(3) its reservoir conditions are better than those in Pingluoba and Qiongxi gasfields; and(4) the Xujiahe 2 Member in Sumatou structure, especially the lower wall of Sumatou 1 fault, has a larger exploration potential.