Effect of Liquefied Petroleum Gas (LPG) on Heavy Oil Recovery Process

Abstract

Unconventional heavy oils are high viscosity and low API density which hinders process recovery from the wellbore. The injection of liquefied petroleum gas (LPG) could be an attractive alternative to improve process recovery. However, LPG dosing must be controlled in order to avoid asphaltenes precipitation. This study aimed to evaluate the feasibility of LPG injection to improve recovery of unconventional heavy oils. The study was based on the computer aided engineering using the software CMG (winprop). The physicochemical properties and composition of heavy oil and LPG were adapted from literature. Both fluids came from a Colombian oil field which had wells with average depth of 7900 ft and porosity of 17 %. The result showed that viscosity values decreased as increase in saturation pressure and temperature. It was convenient to keep the pressure under to 850 Kpa during process recovery in order to control asphaltenes precipitation. The minimum asphaltenes precipitation of 4.8 % (w/w) was obtained from heavy oil to GLP ratio of 0.64. The used of LPG showed as an attractive solvent to improve the process recovery for heavy oils. GLP injection throughout the well could be easily implemented since it is produced in situ during oil recovery.