Downhole monitoring tool design using power line disturbances

摘要

The downhole monitoring tool is a critical component in electrical submersible pump (ESP) wells to monitor downhole parameters such as the pump intake pressure, the temperature of motor winding and oil reservoir, the motor vibration etc. to ensure proper ESP system operation and to optimize production. In this paper, a downhole monitoring tool design method is proposed using power line disturbances. This method is based on the technology of two-way automatic communication system (TWACS). The AC current signal is used for the downhole tool. This new design scheme utilizes an external impedance connecting one phase of the ESP system to the ground on the wellhead, and a controlled thyrsitor connected between the neutral of the ESP motor and the ground by conducting at a specific firing angle and cycles. This design can overcome the impact of single-line-to-ground faults of the ESP system on the communication of downhole tools. The design method is verified through the simulation using PSCAD by case and sensitivity studies. The lab testing is conducted to further validate the effectiveness of the proposed design method.