Research on in-situ oil shale extraction technology based on methane catalytic combustion

Abstract:

In this study， for the methane-containing waste gas generated during the oil shale extraction process， an innovative technological solution， i.e.， catalytic combustion using methane cracking gas containing low concentration of methane to facilitate oil shale extraction， was proposed and analysed by means of detailed simulations with the help of Fluent and CMG software. In Fluent simulation， the role of pore size and length of porous media on the efficiency of catalytic combustion was explored. It is found that smaller pore size and increased catalytic section length could effectively enhance the methane conversion rate and combustion temperature. After model optimisation， the methane conversion rate can reach a high value of 92.4%， and the tail gas temperature can reach 1050 K. The CMG simulation results show that there are significant differences in the temperature field distribution and oil and gas production during the oil shale extraction process under different methane conversion rate conditions. The total oil production reaches the highest value of 20.5 m3 at a methane conversion rate of 92%. Meanwhile， the daily gas production shows an increasing trend with the decrease of the conversion rate， and the peak appears earlier. The study confirms that the scheme can effectively reduce the environmental burden while realising the recycling of waste gas and improving the efficiency of energy use， providing a brand new technical path and methodology for the green and efficient exploitation of oil shale.