A New Technology for the Exploration of Shale Gas Reservoirs

Energy consumption in the world increases 5.6% every year, and alternative resources like shale gas, coal-bed methane (CBM), tar sand, and so on are strongly needed. Shale gas is an unconventional natural gas of enormous potential. Abundant shale gas resides in the form of adsorption gas. Desorption of shale gas is an important mechanism and power source of shale gas reservoir development. Based on the features of shale gas reservoirs, the adsorption/desorption mechanisms, and their influencing factors, high-temperature mixture gas flooding is proposed in this article. Combining the theories of surface chemistry, chemical thermodynamics, and physical chemistry, this article investigates the mechanisms of developing shale gas reservoirs by high-temperature mixture gas flooding, which are illustrated in the following aspects: (1) increasing temperature to accelerate desorption; (2) competitive adsorption, lowering partial pressure of CH4, and accelerating diffusion; (3) increasing moisture on the shale surface; (4) decreasing total organic content (TO C) and improving permeability; and (5) providing displacement energy.