Experimental Determination of Optimized Production Rate and Its Upscaling Analysis in Strong Water Drive Gas Reservoirs

摘要

Gas reservoirs were founded as clean and valuable energy sources. Gas recovery from strong water drive gas reservoirs (WDGR) may decrease because water influx may trap gas. The gas is trapped as an immobile phase. WDGR performance is complicated and depends on many parameters and uncertainty associated with reservoirs. In WDGR, accelerating production rate can let more gases scape but question is accelerating with what flow rate. We investigated the optimum accelerating production rate on WDGR recovery in laboratory scale systems. The experimental flow rates were designed over reasonable range by considering critical rate and Darcy flow condition in first step. By determining optimum flow rate from experiments, the upscaling processes were implemented with a defined theoretical “Sarab” Dimensionless Time Number (TDS) and it was verified by comparing with others porous media length (from 40cm length to 8 cm and 1 meter) .The experimental models were contained distinct gas and water zone (aquifer portion) with thickness proportion of one to two. Gas zone was exposed in initial water saturation in all of experiments. These permeable media were systematically characterized in three lengths. Dimensionless numbers were applied to adequately design the experiments. The pressure operational condition was 3160 psia. We found that optimum flow rate for a WDGR can be obtained in laboratory scale and then can be applied into larger models as well as reservoir sizes with corresponding scale factor of TDS. Connecting of this laboratory flow rate into field application with TDS can be a new revelation into gas recovery and development management of WDGR.