在研究盖层形成和发育的地质条件的基础上,按形成环境将盖层的发育特征分为大厚度连续分布的盖层和小厚度互层断续分布的盖层两大类。通过理论和实例分析,说明了:第一类盖层较第二类盖层具更强的毛细管封闭能力;第一类盖层往往具超压封闭,第二类盖层则不具超压封闭;第一类盖层应具抑制封闭作用,而第二类盖层有则只能为替代封闭作用。第一类盖层较第二类盖层在油气成藏中起着更重要的作用。

Based on studying the geological conditions in-fulencing the formation and development of caprocks.this paper divided the development of caprock into two types of the caprock that owns big thickness and continues dis-tribtuion and the caprock that owns small thickness and interbedded uncontinues distribution according to formation environment. Analysis of theory and actual examples incicates that the caprock owns big thickness and continues distribution has stronger capillary sealing ability than the caprock that owns small thickness and interbedded uncontinues distribution. The caprock that owns big thickness and continues distribution has pressure sealing ability. But the caprock that owns small thickness and interbedded uncontinues distribution dosen’t has pressure sealing ability. The caprock that owns big thickness and continues distribution has restraining concentration sealing ability,but the caprock that owns small thickness and interbedded uncontinuous distribution has replacing concentration sealing ability. The caprock that owns big thickness and continuous distribution plays the more important role in formation of oil or gas pools than the caprock that owns small thickness and interbedded uncontinuous distribution.