鄂西渝东及邻区广泛分布中寒武统覃家庙组膏盐岩层。膏盐岩层之下的下寒武统石龙洞组和上震旦统灯影组储层是本区的重点勘探层系。下震旦统陡山沱组、下寒武统天河板组-牛蹄塘组是本区的两套烃源岩,但因烃源岩的热演化程度高,这两套勘探层系中的烃源一直受质疑。对高-过成熟阶段烃源灶因性质演变所形成的气源接替效应分析表明,烃源灶具有印支期以前的干酪根裂解型与印支-燕山期的油裂解型两种类型的烃源。碳、氧、锶等稳定同位素标记物的流体行为轨迹追踪,进一步证实本区存在多期次的烃源充注,且有效供烃量巨大,计算表明,灯影组和石龙洞组的最大有效供烃量分别为155548.9×108 m3和589255.76×108 m3,认为本区具有较大的天然气资源潜力。

Overburden by wide-distributing Middle Cambrian Qinjiamiao salt rock, both Lower Cambrian Shilongdong and Upper Sinian Dengying hydrocarbon-bearing reservoirs are the important exploration targets in the western Hubei-eastern Chongqing area and adjacent area. However, it has been doubtful to the fact if the hydrocarbon in these reservoirs derived from both the Lower Sinian Doushantuo and the Lower Cambrian Tianheban-Niutitang source rocks because of their high t hermal evolution. According to the effect analysis of replaceable gas source, it is shown that the high-matured to over-matured hydrocarbon kitchens are of the pre-Indosinian kerogen-pyrolyzed and Indosinian-Yanshanian oil-pyrolyzed hydrocarbon sources. The fluid behavior tracking to C , O and Sr stable isotope marks supports the theory of continual y filling of multi-period hydrocarbon sources which provide greatly huge amounts of hydrocarbon. By account, the effective hydrocarbon amounts can reach to 15,554.89×109m3 in Dengying reservoir and 58,925.576×109m3 in Shilongdong reservoir respectively, which means that there is good gas resource potential in the western Hubei-eastern Chongqing area.