Using artificial lifts for heavy oil wells

Abstract

Due to the heavy oil with high viscosity and the natural energy of the reservoir is not enough to make the flowrate which brings economic efficiency. Therefore, it is necessary to energize the flow by using artificial lift methods. This study shows the application of popular artificial lifting methods in the world for an X well model with heavy oil fluid built based on the Compositional model. The application of Gaslift (GL) to product heavy oil is demonstrated to be effective in this article, along with selecting the most optimal injection gas component based on economics, the total flow rate of 1201.3 stb/d thanks to using Flue gas with a injection gas rate of 1 mmscf/d. Gaslift shows the ability to strongly reduce viscosity thanks to the expansion of injection gas, reducing the density of heavy oil inside the tubing. The electrical submersible pump (ESP) method is designed with a production flowrate that is superior to Gaslift at the operating frequency of 60HZ with the flowrate is 1600 stb/d when it strongly reduces hydrostatic pressure at the bottomhole. Through sensitivity analysis, Water cut (WC) is the reservoir parameter that has the strongest influence on production efficiency and shows that Gaslift is not effective when producing heavy oil with high water cut (WC) and low gas oil ratio (GOR), while ESP is the opposite. This study also shows that combining the two GL and ESP methods together improves liquid production efficiency by nearly 15% and saves energy by about 5% compared to ESP alone, while also showing flexibility active in system operation to cope with changes in reservoir conditions.