盖层对水溶相天然气的封闭机理及其研究方法

在研究水溶相天然气及其在盖层孔隙中低速渗流特征的基础上，对盖层对水溶相天然气的封闭机理进行了深入研究，指出吸附作用是造成盖层对水溶相天然气形成封闭的主要机制。当孔隙中自由水完全排出后，盖层才能对水溶相天然气形成封闭作用，且随压实成岩作用增加，对水溶相天然气的封闭能力增强。建立了一套利用压实成岩程度与盖层对水溶相天然气封闭能力之间的关系研究盖层对水溶相天然气封闭能力的研究方法，并将其应用于松辽盆地三肇凹陷泥岩盖层对水溶相天然气封闭能力的研究中，结果与实际地质条件十分吻合，表明该研究方法研究盖层对水溶相天然气封闭能力是可行的。

Seal Mechanism of Caprock to Gas in Water-dissolving Phase and Its Research Method

Based on the characteristics of gas in water dissolving phase and its low speed flow through caprock,this paper made a deep research for seal mechanism of caprock to gas in water dissolving phase.Pointed out adsorption to be main sea1 mechanism of caprock to gas in water dissolving phase.After free water in pore of caprock was displaced,caprock formed seal ability of caprock to gas in water dissolving phase.With increase of compaction and diagenesis,seal ability of caprock to gas in water dissolving phase has increased.Using the relation between compaction and diagenesis degree and seal ability of caprock to gas in water dissolving phase,this paper established a method studying seal ability of caprock to gas in water dissolving phase,in Sanzhao sag of Songliao Basin.The results tally with actual geological conditions.It indicates that the method is practical to study seal ability of caprock to gas in water dissolving phase.