Simulation of Enhanced Coalbed Methane Recovery

Abstract

In this project simulation of the Enhanced Coalbed Methane Recovery (ECBMR) is investigated. Two simulation models were built in Petroleum Experts and CMG (GEM) Software. Prediction of the ECBMR is a complex process. It is affected by different factors, such as matrix shrinkage and swelling, the interaction of the injected gases with the seam, coalbed methane (CBM) and each other. A comprehensive investigation of ECBMR technics was achieved. Mechanisms of nitrogen (N2) and carbon dioxide (CO2) injection were studied and compared regarding the influence on recovery efficiency. N2 alternating CO2 injection and CO2 alternating N2 injection simulations were performed in the project. Dependence on the sequence of the injection, injection gases ratio and frequency were addressed. Created models were used to analyse the production prediction of mixture injection of N2 and CO2 with different composition of injection mixture. Optimal regarding methane production recovery was discovered. Comparison of ECBMR injection variations was performed. This project results could be helpful for further ECBM modelling studies.