Thermal-Fluid Coupling Simulation on In-situ Unsteady Pyrolysis of Fuyu Oil Shale

Numerical simulation on heat transfer and permeability of Fuyu oil shale reservoir after hydraulic fracturing was carried out by using thermal-fluid coupling analysis model. It is found that the fluid mainly flows out of the fracture along the oil shale bedding direction. However, as the temperature increases, the porosity increases and a little fluid flows out of the primary pores of the oil shale. The seepage field pressure shows a downward trend in the same section from the fracture perpendicular to the oil shale bedding. The heat conduction of fluid to oil shale formation was mainly in the direction of fracture. As the heating time increases, the oil shale cracks on both sides of the fissure, and with the porosity increase, the diffusion rate of nitrogen to the oil shale reservoir is also improved. After 40 days of heating, the oil shale around the fracture first reaches the cracking temperature. Between 60 and 100 days of heating, the average temperature of oil shale rises from 500 K to 650 K, and the whole oil shale can be effectively cracked. © 2019, Editorial Department of Journal of Northeastern University. All right reserved.