Nowadays, the world is facing the depletion of developed reserves and the exploitation of fields with poor reservoir features. These factors are forcing oil producers to use low-capacity high-head electric centrifugal submersible pump units (ESP). The use of such ESP in oil production causes pump temperature to rise to about a hundred degrees centigrade. Increasing the temperature strength of the cable line used as part of the ESP reduces the number of failures in terms of the electrical component. In order to reduce the number of ESP failures due to cable line fusing, oil producers started using cable lines with operating temperatures of over 200оС. Increasing the temperature strength of the cable line used as part of the ESP leads to a partial decrease in failures due to a reduction in the electric resistance of the “cable-motor” system. Meanwhile, failures of ESPs due to salt deposition in the pump stages started to grow. In the absence of any theoretical insight into the salt deposition phenomenon, ESP manufacturers started providing oil producers with various devices to protect pump stages from salt deposition. However, it soon became clear that these devices (containers with chemical salts) show no tangible results in terms of salt deposition elimination; hence, over the past few years, oil production enterprises have been maintaining the proper operation of ESPs by the regular dosing of chemicals to the pump suction or by hydrochloric acid treatment. Investigation of the failed ESP units has reliably ascertained the following: formation and effect of high temperature in and around the centrifugal pump; effect of the pump’s high temperature on the adjacent cable line; application of cable lines with high operating temperatures leads to salt deposition in the centrifugal pump chamber; salt deposition accompanies temperature deformation of the cable line’s insulation; acid treatment does not protect the ESP unit against salt deposition; acid treatment may result in the wear of a flow string; Therefore, solution of the salt deposition problem should start with an investigation of the dependence of a centrifugal pump’s temperature on the oil reservoir’s working parameters. The solution of many oil production problems and a reduction in oil recovery costs can only be achieved by means of ESP control automation. The described revolutionary studies of ESP operation in oil recovery will lay the foundation for a complete robotization of oil production.
DOWNHOLE REACTIVE POWER COMPENSATION
