In the evaluation of mud cap layers , cross - plot and nuclear magnetic resonance log porosity curve overlap method was adopted to the comprehensive analysis of yn2 well tight sand reservoir and 3 sets of reservoir - seal combinations are found accurately 笔者在重点对泥质盖层进行研究评价的同时,采用交会图法和核磁共振测井孔隙度曲线重叠法对具有致密砂岩盖层的yn2井进行了全面地储盖组合评价分析,准确地找到了三套储盖组合。