在异常孔隙流体压力形成机制及条件的基础上,对异常孔隙流体压力在封闭各种相态天然气的作用方面进行了研究。指出:异常孔隙流体压力不能直接对游离相天然气进行封闭,但可使泥岩盖层毛细管封闭能力增强,间接地对封闭游离相天然气起作用;异常孔隙流体压力也不能直接对水溶相天然气进行封闭,但可通过使泥岩盖层吸附阻力增强,间接地对水溶相天然气起作用;异常孔隙流体压力也不能直接对扩散相天然气进行封闭,但可通过形成异常含气浓度,间接地对封闭扩散相天然气起作用。

Based on the study of the formation mechanism and conditions of abnormal porefluid pressure. The affect of abnormal pore fluid pressure to the seal of gas in each phase was deeply studied. Abnormal pore fluid pressure was considered notto seal gas in free phase directly, it can play an indirect role in sealing gas in free phase through increase of capillary seal ability of mudstone caprock.Abnormal pore fluid pressure was considered not also to seal gas in water-dissolving phase directly, it can play an indirect role in sealing gas in water-dissolving phase through increase of adsorptive fore of mudstone caprock. Abnormal pore fluid pressure was considered not to seal gas in diffusion phasedirectly,it can play an indirect role in sealing gas in diffusion phase through the formation of abnormal gas-bearing concentration of mudstone caprock.