从盖层质量、地层水条件、异常地层压力和构造作用等四个方面，对冀中坳陷东北部石炭系—二叠系煤系地层分别进行了煤成气保存条件的单因素成图评价分析。综合各项指标，建立了煤成气保存条件综合评价体系，划分出“好”、“较好”和“较差”三个评价等级。认为研究区保存条件好的区域主要有武清凹陷中南部、里坦凹陷西南部、文安斜坡北部的信安地区和西部的苏桥以南地区，较好的区域主要有饶阳凹陷北部和里坦凹陷的大部分地区。

Preservation of coal-related gas depends on the factors that include cap-rock quality, formation water condition, abnormal formation pressure and tectonism. The preservation conditions of the coal-related gas are evaluated by diagramming these single-factors and a comprehensive evaluation system of preservation conditions is set up to the coal-related gas in Carboniferous-Permian coal measure strata in the northeastern part of Jizhong Depression. Three grades of preservation conditions, the good, the fair and the poor, are classified in the evaluation system. According to the evaluation grades, the potential areas belonging to the “good” preservation condition are the central to southern part of Wuqing Sag, the southwestern part of Litan Sag, and the northern part (Xin’an) and the western part (Suqiao) of Wen’an Slope, and the areas belonging to the“fair”are the northern part of Raoyang Sag and the most part of Litan Sag.