准噶尔盆地玛湖西斜坡百口泉组储层特征研究

环玛湖凹陷T/P不整合面之上,三叠系百口泉组为一套砂砾岩为主的沉积体,其内部结构复杂,储层孔隙形成机理及物性的影响因素复杂,给储层预测带来困难。利用岩石薄片、铸体薄片、扫描电镜及电子探针等微观手段,结合岩心观察、物性分析,对玛湖西环带斜坡区百口泉组储层的孔隙形成机理进行研究,发现该区砂砾岩储层主要发育三类孔隙,剩余粒间孔、泥质杂基收缩孔、长石溶孔。其中剩余粒间孔和泥质杂基收缩孔主要发育于以扇三角洲前缘颗粒流沉积为主体的百一段细砾岩中,前者因砾石以及砾石间石英、长石等刚性颗粒的支撑而形成,后者因原始孔隙中伊/蒙混层矿物向伊利石转化形成;百二段和百三段少量发育的长石溶孔主要存在于扇三角洲平原泥石流沉积的含泥含砂中砾岩和河道砂岩中,因碱性长石被源于二叠系风城组烃源岩的有机酸溶蚀而形成。并且颗粒流成因的砂质细砾岩物性和含油性明显好于泥石流沉积的含泥、含砂中砾岩。

Research on reservoir characteristic of Baikouquan Formation in Mahu western slope of Junggar basin

above the T/P unconformity Central Mahu Depression , Triassic Baikouquan formation sediments in glutenite, Its internal structure is complex, pore formation mechanism and factors affecting the reservoir physical properties is also complex,which is difficult to predict reservoir. By the means of microscopic flakes of rock, cast thin, scanning electron microscopy and electron probe, combined with core observation, physical analysis,We Conduct research on Pore formation mechanism of glutenite reservoir of Triassic Baikouquan Formation,and find that there are three major void in the area,they are the remaining intergranular pore, muddy shrinkage holes and feldspar dissolution pores. The remaining intergranular pore and muddy shrinkage holes mainly present in the particle flow deposition fine conglomerate of the first member of Triassic Baikouquan Formation. The former formed because of the particulate support by gravel and quartz, feldspar and other rigid among gravel. The latter formed because of the transformation from illite / smectite to illite. feldspar dissolution pores which formed because of alkali feldspar dissolution by Organic acids from the Permian source rocks mainly developed in medium conglomerate containing mud and sand or the river sandstone of the second and third section of Triassic Baikouquan formation.and fine conglomerate significantly better than medium conglomerate containing mud and sand in terms of the physical properties and oiliness.