Evaluation of shale gas resources of the Sinian Doushantuo Formation in the southern Huangling anticline, western Hubei Province

With the first discovery of the world's oldest shale gas in the Sinian Doushantuo Formation on the southern limb of the Huangling anticline in the western Hubei Province, the gas-bearing properties of the dark shale in this layer have been confirmed. The gas content and density data of the dark shale of the Sinian Doushantuo Formation in the study area were obtained by gas content and rock and mineral analyses of the core samples from the well ZD-1. Based on the interpretation of regional seismic reflection profiles and well data of ZD-1 and ZD-2, we delineated the distribution and thickness variation of the black shale in detail, and defined the volume of the gas-bearing shale. The resource potential of the Lower Sinian Doushantuo Formation on the south limb of the Huangling anticline was determined by the probabilistic volume method. The gas resource was calculated, ranging (85-303)×10⁹ m³, and the median resource was 195×10⁹ m³, which indicates that the layer has a good shale gas resource potential. It was recommended as a shale gas exploration target in the western Hubei Province.