川东南丁山地区上奥陶统五峰组—下志留统龙马溪组实施的两口页岩气探井,优质页岩段(一般TOC≥2.0,)实测总含气量,DY1井平均3.07 m3/t,DY2井平均6.79 m3/t.对比发现,优质页岩段烃源条件相似:丁山地区五峰组—龙马溪组沉积早期处于深水陆棚沉积环境,优质页岩段总体厚度较大,一般在30~35.5 m之间;平均TOC基本相当,在3.42,~3.95,之间;热演化程度适中,R o值一般大于2.0,.研究认为保存条件差异是造成丁山地区页岩含气性差异的关键因素:距离齐岳山断裂较近的DY1井区,页岩高角度缝发育,加上埋藏浅,页岩气侧向逸散严重,页岩含气性相对变差;远离齐岳山断裂的深埋藏平缓带是有利的页岩气藏发育带.

There are significant differences in the total gas content measured in high-quality shale section (TOC≥2.0,) of the Upper Ordovician Wufeng Formation and the Lower Silurian Longmaxi Formation in the Dingshan area of southeastern Sichuan Province. The average gas content of well DY1 is 3.07m3/t, and the average gas content of DY2 is 6.79m3/t. In the study area, the source conditions of the high-quality shale are similar: the total thickness in the early stage of Wufeng Formation-Longmaxi Formation is relatively large, usually between 30m and 35.5m; the average TOC of the shale is almost 3.42,~3.95,; shale thermal evolution is moderate, Ro value is generally greater than 2.0,. The comprehensive study suggests that the preservation conditions are the key factors that contribute to the difference in gas content of shale in Dingshan area. The deep buried area, where is far away from Qiyueshan Fault, is a favorable zone for shale gas reservoirs. While in the area close to Qiyueshan Fault, the shale gas is relatively poor because the lateral dissipation of shale gas is more serious, due to the high angle fractures and the shallow burial of the shale.