Evaluation of wax deposition in oil wells based on improved analytic hierarchy process-entropy method

Abstract This study built a quantitative model for evaluating the wax deposition in oil wells based on the improved analytic hierarchy process-entropy method (AHP-EM), considering multiple response wellhead parameters including maximum load (weight 0.039), minimum load (weight 0.007), load difference (weight 0.246), area of the indicator diagram (weight 0.595), maximum upstroke current (weight 0.016), maximum downstroke current (weight 0.004), and sum of upstroke and downstroke currents (weight 0.094). The application results in the QX oilfield indicated that there was an inflection value of 0.87∼0.92 in the wax deposition index 1∼3 days before the occurrence of wax jam. In addition, the implementation effect of dewaxing measures such as hot washing was quantitatively evaluated based on the change in wax deposition index pre- and post-dewaxing. Therefore, the developed AHP-EM model realizes the real-time evaluation of the wax deposition in oil wells, which provides valuable reference and guidance for the production and management of oilfields.