Inflow performance relationships for layered solution-gas drive reservoir

Inflow performance relationship (IPR) is a very important tool to forecast well performance. Existing IPR models are idealistic since they are developed for homogeneous reservoirs; therefore, they are inappropriate for layered systems. Consequently, there is a need for IPR models that efficiently describe layered reservoir performance. This study investigates the effects of reservoir heterogeneity on IPR for layered solution-gas drive reservoirs. Multiphase flow in both two and multilayer reservoirs was simulated. Both fluid cross flow and no fluid cross flow among layers were considered. A stochastic simulation algorithm was used to generate various permeability realisations among layers. Three geostatistical models using uniform, Gaussian, and bimodal probability distributions were used to grasp optimum match between real reservoir behaviour and simulated data. The generated data were scrutinised to develop two accurate IPR equations. The first equation describes the well behaviour under current flowing conditions, whereas the second equation can be used to forecast future well performance.