致密砂岩气藏作为非常规油气资源的主力，已经越来越受到重视。由于致密砂岩气藏不同于常规气藏，具有储层致密、物性差、电性响应不明显的特点，因此有必要针对致密砂岩气藏的有效厚度下限进行研究。以鄂尔多斯盆地某气田上古生界致密砂岩气层为例，在“四性”关系研究的基础上，较为系统地阐述了致密砂岩气藏有效厚度下限确定的方法，重点探讨了测试法、经验统计法、压汞参数法和测井曲线法。实际试气数据和横向对比验证表明，这些方法确定的有效厚度下限合理，符合研究区实际地质特点，操作简单，应用效果好。

There is more and more attention being paid to the tight sandstone gas pools which have been the major force of the unconventional petroleum resources.As the tight sandstone gas pools are different from the conventional ones,whose reservoirs are tight,the rock property is bad,and the electrical response is unclear,thus it is necessary to clarify the lower limit of effective thickness for the tight sandstone gas pools.Based on the study of “the four property relationship”,this article takes the Upper Paleozoic tight sandstone gas reservoir of some gas field in Ordos basin as example,and systematically describes the method of determining effective thickness lower limit of tight sandstone gas pools,and the test method,the experience statistics method,the mercury injection parameter method and the logging curves method are respectively discussed.Compared with the actual gas testing data,the effective thickness lower limit determined by these methods is reasonable and meets up with the actual geological characters,of which the operation is simple and applies well.