A novel material-balance approach for estimating in-place volumes of gas and water in gas reservoirs with aquifer support

Abstract Applications of the traditional static material-balance method in gas reservoirs become a challenge with production maturity due to variability aquifer influx, infill drilling, and production-operational changes offset wells, among others. Besides, some existing modeling approaches involve trial-and-error method, making solution outcomes nontrivial. This study proposes new methodology for analyzing data involving water-drive reservoirs. The main findings this include following: (1) A straight-line plot that yields water in-place volumes, (2) modified-( p av / z )* exhibits an x -intercept initially-in-place, similar conventional-( ) plot, (3) definition degree support is quantifiable using data. Synthetic verified proposed approach, whereas field dataset provided validation.