Optimized pressure pulse-decay method for laboratory estimation of gas permeability of sorptive reservoirs: Part 2 - Experimental study

CO2 was used as the test fluid to investigate the effect of sorption on pressure variation due to its higher affinity towards coal than methane. The experimental results showed that sorption effect was eliminated, leading to accurate permeability values. A similar permeability trend with pressure drawdown, as previously measured for San Juan basin coal, was established. Also, comparison of the measured pressure decay plots and those obtained from computer simulation exhibited perfect matches, indicating that Brace et al.'s solution can be used for permeability estimation of sorptive rocks by adopting the optimized transient technique.