Analysis of Combined Gas Lift and Electric Submersible Pump Lifting Wellbore Fluid Production in a Heavy Oil Block in South China Sea

In recent years, as a kind of unconventional oil energy, heavy oil has large reserves and wide distribution, and the issue of marine heavy oil exploitation has gradually attracted attention. Especially, the temperature near the mud line was low, the viscosity of heavy oil increases exponentially, and it was difficult to flow. Therefore, taking appropriate lifting measures to improve wellbore flow had become the focus of current research. In this paper, multi-phase flow dynamic theory was used to model artificial lift of heavy oil well in a certain block in the South China Sea, including gas lift, gas lift-electric submersible pump (GL-PCP) combined thermal insulation pipe technology. Compared with no lifting measures, the fluidity of heavy oil vertical wellbore was explored. The simulation results showed that the liquid production of heavy oil increased obviously with the injection of natural gas. With the addition of electric submersible pump, the liquid production effect of gas lift was improved compared with that of single lift, and the pressure gradient was obviously reduced. In addition, the fluid temperature near the mud line was low, and the minimum temperature could be appropriately raised by combining the insulation pipe. It was of great significance to optimize artificial lifting method of heavy oil and ensure wellbore fluidity.