Petrologic and Geochemical Characteristics of Shales

Shale systems are different from conventional oil and gas reservoirs due to that they are both source rocks and reservoirs. The source rocks characteristics includes the organic matter type, organic matter richness, and thermal maturity of organic matter, and controls the hydrocarbons generation capacity. This chapter summarizes the mineralogical properties and organic geochemical characteristics of the gas shales in the Jiaoshiba area from the Sichuan Basin. Then, shale lithofacies is introduced to describe the petrologic and geochemical characteristics of shales. It provides an indicator to comprehensively characterize reservoir quality, and is the basis for shale gas exploration and development.