Study on two-phase flow and heat transfer in offshore wells

• We block the wellbore into several segments to establish the mathematical model of flow and heat transfer.
• The model takes the Joule–Thomson effect and the heat emitted by pump and cable into consideration.
• The Joule–Thomson effect of condensate gas increases the temperature and pressure drop.
• The heat emitted by pump and cable slows the reduction of temperature and pressure above the pump.
• Temperature and pressure drops are different as water cut or gas–oil ratio changes.

According to the characteristics of offshore wells using Electrical Submersible Pump (ESP), the coupled calculating method is adopted to establish the flow and heat transfer model of wellbore. The flow and heat transfer model is compiled by C language and validated by field measurements. The numerical calculation results show that the factors of marine environment, heat emitted by pump and cable, and the Joule–Thomson effect have significant impact on the wellbore temperature and pressure distribution. When temperature decreases on the condition of low water cut and high gas–oil ratio, the increase of gas–liquid ratio and decrease of density will retard the pressure reduction. However, when the temperature decreases on the condition of high water cut and low gas–oil ratio, decrease of the gas–liquid ratio and increase of density will accelerate the pressure reduction.