Journal of Canadian Petroleum Technology, Vol.44, No.9, 37-43, 2005
Steam Alternating Solvent process: Lab test and simulation
A new heavy oil recovery process, the Steam Alternating Solvent (SAS) process, is studied by lab experiments and corresponding numerical simulation. The SAS process involves injecting steam and solvent alternately, using well configurations similar to those in the SAGD process. This process is designed to combine the advantages of the SAGD and VAPEX processes to minimize the energy input in heavy oil and bitumen recovery. Lab experiments were conducted using a 2D high-pressure/ high-temperature model. One baseline SAGD test and one SAS test were performed using an oil sample from Burnt Lake. A mixture of propane and methane was used as the solvent in the SAS test. The results showed that the energy input in the SAS process was 47% lower than that of the SAGD process for recovering the same amount of oil. The post-run analysis revealed that asphaltene precipitation occurred in the porous medium. Numerical history matching of the test data using Computer Modelling Group's STARS reservoir simulator captured the main features of the process.