Thermal simulation of shale gas recovery involving the use of microwave heating

Recent technological advancement in drilling for shale gas such as hydraulic fracturing, has meant that more gas can be recovered from the ultra-tight matrix of the shale formation. However, significant quantities of adsorbed gas are still left unproduced even with this breakthrough in accessing gas previously unattainable due to the low permeability of shale. In this paper, a coupled electromagnetic –thermal model has been developed to investigate the production of adsorbed gas from shale gas reservoirs using microwave heating. A dual porosity –dual permeability model is developed for the system of shale gas with account of both viscous and Knudsen diffusion in the matrix. Results from simulation indicated that microwave heating can improve cumulative production by 25% in a period of one year by accelerating desorption of the adsorbed gas. Further results also indicated higher penetration depth for microwave frequency of 915 MHz. This study provides useful insights into microwave assisted shale gas recovery. •Both Viscous and Knudsen diffusion is considered in a dual porosity/dual permeability model for shale gas reservoir.•Thermal stimulation of shale gas reservoirs using microwave heating to target adsorbed gas.•Use of microwave Frequency of 915 GHz showed higher cumulative production.•Cumulative production increased by 25% using microwave heating compared to cases without microwave heating.