Geological Conditions and Prospecting Area Delineation of Gufeng Formation Shale Gas in the Jingshan Area, Hubei Province

The rock samples of the Gufeng Formation are tested in their rock assemblage, organic geochemistry, and reservoir characteristics to evaluate the geological conditions and resource potential of shale gas in the Jingshan area, Hubei Province. The thickness and organic carbon contents (TOC) of the Gufeng Formation shales in the study area are between 55.2 ~ 58.3 m and 1.75% ~ 6.39% respectively. Their kerogen is type I, and the vitrinite reflectance (Ro) is 1.23% ~ 1.72% with the average value of 1.58%, which indicates that the shales are in the stage of over-mature gas generation. They develop a variety of pores and fissures with the average porosity of 4.29%. The samples consist of mainly quartz and carbonate and minor clay minerals. The average fitted gas content of the Gufeng Formation is 2.21 m³/t. The research results show that: (1) the mud shale of the Gufeng Formation in the study area is thick, and has potential for shale gas reservoir with good hydrocarbon generation ability; (2) The Gufeng Formation has high content of brittle minerals, which is conducive to fracturing reformation; (3) According to the superposition method to predict, the study area can be subdivided into two prospective, such as the Yonglong-Long Beach area and Qianchang-Yuxin area.