Experimental and Simulation - Assisted Feasibility Study of Gas Injection to Increase Oil Recovery Using a Combination of Semi-VAPEX and GAGD Techniques

Gas injection into heavy oil reservoirs could result in high ultimate recovery of oil. Experimental studies showed that an application of a combined technology of Gas Assisted Gravity Drainage (GAGD) and Vapor Extraction (VAPEX) could increase final oil recovery of a candidate viscous oil reservoir. In this paper the results of laboratory investigation are presented, including Pressure-Volume-Temperature (PVT) studies, physical model experiments and simulation studies to evaluate the gas injection process for heavy oil reservoirs recovery. The study examined the effect of two different gases on viscosity reduction and oil swelling. Physical model tests were carried out to investigate the effect of gas injection on oil recovery. Another study (simulation model) predicted the performance of the reservoir under gas injection in a model. This simulation study was established on a sector of the reservoir.