book-leaf clay

Its formation mechanism includes well-developed net-shaped clay in tight sandstone which fill the intergranular pores and form micropores, and water-locking effect which can enhance capillary pressure and reduce greatly the gas permeability as well so as to make it the effective caprock of gas reservoir.

英南2气藏之上非常规致密砂岩作为盖层,形成机理是致密砂岩中网状粘土发育,充填于粒间,形成大量微孔隙,水锁效应增大毛细管压力,极大地降低气体渗透率使其成为气藏有效盖层。