Experimental Investigation of Cyclic Solvents Injection to Enhance the Production in Heavy Oil Reservoirs

Abstract

Solvents injection for thin layered reservoirs that contains a very high viscous crude oil is an alternative way to improve the oil mobility, reducing its viscosity and increase the production. in this mechanism, the oil viscosity is reduced by dissolving the solvents and then becomes more capable to flow through the porous media, during the production period the production rate is also improved by gas expansion mechanism. However, during the production period the sample pressure is abruptly depleted due to the viscous fingering of solvents ahead of oil to outflow out of the sample. This study shows an experimental investigation of cold production of heavy oil by using the solvent as an enhancing technique to improve the recovery of heavy oil in thin reservoirs, experimental model has been designed to make several runs for injecting the solvents in cyclic process "huff & puff" to analyze the saturation of the sample and production conditions at the end of the runs. Unlike the vapor extraction process that is called VAPEX, where two horizontal wells ( injector and producer) are designed to inject the gas by one well and produce by the other well, cyclic solvent injection is using only one well as solvent is initially injected for certain period of time, followed by soaking period then oil is produced from the same well for production period.