自生绿泥石对砂岩储集层影响的新认识

通过对鄂尔多斯盆地西部姬塬地区三叠系延长组的岩石铸体薄片分析和扫描电镜的观察认为,早期自生绿泥石胶结对原生孔隙的转化、保存和改造起重要作用,主要表现为占据原生孔,并将其转化为黏土矿物晶间孔的形式,从空间上阻碍硅质胶结、碳酸盐胶结对孔隙的破坏,为后期流体改造储集层提供了通道;其亲油的黏土矿物属性,为后期油气在低孔、低渗储集层中成藏提供了条件。另外,因绿泥石化学性质较活泼,易发生水解,在开发具有绿泥石胶结的油藏时,应考虑到黏土矿物的敏感性。研究认为,绿泥石环边形成后储集层仍有较强的压实现象,前人认为的抗压能力可能被夸大。

New Sight about Affect of Authigenic Chlorite on Sandstone Reservoir

Early authigenic chlorite cementation is of significant effect on the conversion,preservation and reconstruction of primary pores,based on the casting thin section and SEM analyses of Triassic Yanchang formation of Jiyuan area in western Ordos basin.It mainly occupies primary pores,converting them into intercrystal pores of clay minerals which can impede the damages of siliceous and carbonate cements to the pores,providing pathways for late fluid reconstruction of reservoirs.Its oil-wet clay mineral attribu...