根据岩心及薄片观察、实验分析、录井及测井解释，认为杨庄组、洪水庄组和馒头组是冀中坳陷中上元古界—下古生界碳酸盐岩潜山内幕最主要的盖层。盖层岩性以泥质岩为主，其次为泥质白云岩、泥质灰岩及致密白云岩或灰岩，孔、渗性普遍较差。盖层在宏观上受岩性、泥质含量、分布规模等因素的影响，微观上受突破压力、物性、遮盖系数等的约束。依据上述因素，将冀中坳陷碳酸盐岩潜山内幕盖层划分为4 类。综合评价得出，杨庄组为Ⅲ类（中等）盖层、洪水庄组为Ⅱ类（较好）盖层、馒头组为Ⅰ类（好）盖层。

Based on the observation of core and thin section, experimental analysis and well logging interpretation, it is considered that Yangzhuang Formation, Hongshuizhuang Formation and Mantou Formation are the main carbonate buried hill inner cap rocks fromChangcheng systemto Ordovician in Jizhong Depression. The lithology of the cap rock is mainly argillaceous rock, followed by argillaceous dolomite, argillaceous limestone and dense dolomite or limestone. Both the porosity and permeability are low. The essential macroscopical controlling factors for the cap rock are lithology, shale content and distribution scale, while the microcosmic controlling factors are breaking pressure, porosity and permeability, envelop coefficient etc. Based on the above factors, the carbonate buried hill inner cap rock in Jizhong Depression is divided into four types. Yangzhuang Formation is evaluated as type Ⅲ （middling cap rock）, Hongshuizhuang Formation is evaluated as typeⅡ （better cap rock）, andMantou Formation is evaluated as typeⅠ（best cap rock）.