上扬子地区龙马溪组与筇竹寺组的差异性分析

Study on the Difference Between Longmaxi Formation and Qiongzhusi Formation in Upper Yangtze Area

通过对上扬子地区筇竹寺组和龙马溪组海相页岩储层特征的对比分析,认为2套地层在岩相古地理、有机质热演化程度、含气性和保存条件存在差异。差异对比的结果表明:龙马溪组页岩气富集区呈现连片式的相对连续分布,可通过TOC质量分数平面分布和构造活动强度筛选有利区,筇竹寺组页岩气富集区呈现孤立分散状,应该在弱改造、底板完整的地区筛选成熟度相对较低的区块进行有利区勘探。

The information from drilled wells shows that there is difference between Qiongzhusi Formation and Longmaxi Formation in the upper Yangtze area in the distribution characteristics of the marine shale gas. According to the comparative analysis of the reservoir characteristics,it is held that there is difference in lithofacies paleogeography, organic matter maturity, gas-bearing ability and preservation condition. The research result of the difference indicates that in Longmaxi Formation,the shale gas enrichment areas continuously or quasi-continuously distribute, the favorable zones of the shale gas can be selected by the plane distribution of TOC mass fraction and the strength of tectonic activity;in Qiongzhusi Formation, the shale gas enrichment areas distribute in isolation, the favorable zones of the shale gas should be selected from the lower maturity blocks in the areas with weak tectonic conditions and complete floor.