Numerical Calculation Method of the Wellbore Temperature Field for Electric Heating Heavy Oil Thermal Recovery

The wellbore temperature field of electric heating-based heavy oil thermal recovery forms the basis of the thermal recovery operation parameters design. Based on the heat transfer theory and the calculation method of wellbore temperature/pressure fields for gas-liquid two-phase flow, the wellbore temperature field numerical calculation method for continuous electric heating and electromagnetic nipple heating processes that considers the influence of temperature on the thermal properties of heavy oil was established. By taking the Well X in Dagang Oilfield as an example, the wellbore temperature fields of continuous electric heating and electromagnetic nipple heating processes under different heating powers were calculated. The calculation results showed that the relative error between the wellhead temperature calculated with this model and the measured one was only 3.10%. This met the requirements of engineering design accuracy, and verified the validity and accuracy of this calculation method. The wellbore temperature profile formed by continuous electric heating was smooth and continuous, whereas the profile formed by electromagnetic nipple heating process was zigzag and had dramatic fluctuations. The wellhead temperature formed by the continuous electric heating process was higher than that of the electromagnetic nipple heating, and the average temperature of the continuous electric heating process was lower than that of the electromagnetic nipple heating process. The research results could provide guidance and reference for the selection of electric heating heavy oil thermal recovery processes and operation parameters design.