Patent AU-2015264810-A1 (AU)
Title: Design method and apparatus for reconstructing coal reservoir
Inventor: YANG YONG
IPC: E21B43/25
Filed: 2015-12-02
Abstract: The present invention provides a design method and a design apparatus for coal reservoir reconstruction, pertaining to the field of coal bed gas exploration. The method comprises: obtaining a thickness, an effective porosity, a phase change reconstruction radius and a phase change reconstruction temperature of the coal reservoir, and obtaining a pitshaft thermal loss efficiency of an injection well; determining a dosage of phase change fluid and a dosage of spacer fluid according to the phase change reconstruction radius and the effective porosity of the coal reservoir; determining an injection displacement when injecting fluid to the coal reservoir and a wellhead maximum pressure of the injection well according to a fracture pressure of the coal reservoir; determining a cooling capacity needed for phase change reconstruction of the coal reservoir according to the dosage of phase change fluid, a specific heat capacity of pore medium in the coal reservoir, a density of the pore medium in the coal reservoir and the phase change reconstruction temperature; determining a dosage of cooling medium fluid and a dosage of cooling source according to a pitshaft thermal loss efficiency, a specific heat capacity of the cooling medium fluid and a temperature of the cooling medium fluid after thermal exchange with the ground; and then reconstructing the coal reservoir through phase change of the phase change fluid. By applying the present invention, the efficiency of reconstruction to the reservoir can be improved. Obtaining a thickness, an effective porosity, a phase change reconstruction radius and a phase change reconstruction temperature of the coal reservoir, and obtaining a pitshaft thermal loss efficiency of an injection well Determining a dosage of phase change fluid and a dosage of spacer fluid according to the phase change reconstruction radius and the effective porosity of the coal reservoir, and determining an injection displacement when injecting fluid to the coal reservoir and a wellhead maximum pressure of the injection well according to a fracture pressure of the coal reservoir Determining a cooling capacity needed for phase change reconstruction of the coal reservoir according to the dosage of the phase change fluid, a specific heat capacity of S103 pore medium in the coal reservoir, a density of the pore medium in the coal reservoir and the phase change reconstruction temperature, and determining a dosage of cooling medium fluid and a dosage of cooling source according to the pitshaft thermal loss efficiency, a specific heat capacity of the cooling medium fluid, and a temperature of the cooling medium fluid after thermal exchange with the ground Injecting the phase change fluid, the cooling medium fluid, the cooling source and the spacer fluid into the coal reservoir through the injection well according to the phase change reconstruction radius, the phase change reconstruction temperature, the dosage S104 of the phase change fluid, the dosage of the spacer fluid, the dosage of the cooling medium fluid, the dosage of the cooling source, the injection displacement, the wellhead maximum pressure and the cooling capacity needed for phase change reconstruction of the coal reservoir, performing condensation treatment to the phase change fluid using the cooling source, and then reconstructing the coal reservoir through phase change of the phase change fluid Fig. 1 7179836_1 (GHMatters) P101733.AU GARYC