Proxy modelling for rapid optimisation of miscible CO₂-WAG injection in heterogeneous clastic reservoirs: A case study from Southern Iraqi oil fields

Multiple simulation runs are required to optimise and quantify uncertainty and sensitivity analysis to determine and rank the impact of reservoir and operating parameters on the incremental oil recovery (∆RF) under miscible CO₂-WAG flooding. The central composite design (CCD) was employed to create a statistical proxy model for ∆RF as a function of seven reservoir and operating parameters. Statistical analysis was employed to check the model adequacy. The importance and effect of variables that result to higher predicted ∆RF were investigated. As an analogue of the Nahr Umr reservoir, the reservoir understudy, the proxy model can be roughly applied to predict the ∆RF during the miscible CO₂-WAG injection at depending on uncertainty. The reliability of the proxy model has been demonstrated based on many statistical tools.