Effect of water and gas injection schemes on synthetic oil rim models

Abstract

Oil recovery in oil rim reservoirs is usually affected by reservoir and operational parameters. An experiment was designed to develop various types of oil rims with a broader range of uncertainties. Mensuration analysis was used to create the basic grid designs, while the Eclipse software was used to incorporate pressure, volume and temperature and reservoir fluid properties to create a black oil model for oil rims. The reservoir models were conditioned to a simultaneous production scheme through which a response surface model was generated to represent oil recovery for all the models. The models were later classified into drive mechanisms based on the results from the Pareto analysis. Various secondary injection schemes were carried out based on reservoir geometry to investigate their response on oil recovery. Results show that for single injection schemes, oil recovery from water down-dip (6.5%) and water up-dip (4.37%) was higher than gas scheme injection for reservoir model 10. Oil recovered from up-dip and down-dip water injection (7.1%) was higher than gas up-dip and down-dip injection (0.03%) for reservoir model 10, and for the same model, an oil recovery of 7.7% and 5.63% was recorded for gas up-dip and water down-dip injection and gas down-dip and water up-dip injection, respectively. The final analysis shows that there is an appreciable increase in oil recovery when injection rates are increased as seen in water down-dip and up-dip injection with 15.43% recovery for reservoir model 10.