Long-term downhole monitoring and controlling production from wells based on high-temperature DC power line communication

DC power line communication (PLC) technique has been proven to be efficient for single-core cable communication and DC power supplies. However, the effect of high temperature will have a great influence on the performance of DC-PLC for downhole applications. In this paper, a high-temperature DC-PLC system that enables the operation to 150 °C is presented for long-term downhole production monitoring. Based on the DC-PLC techniques, the downhole system with single-core cable for long-term oil production monitoring and controlling is investigated. In order to improve the transmission efficiency, an adaptive PLC decoding algorithm is proposed to accommodate the single-core cables due to the long-term effect of high temperature, high pressure as well as vibration of the bad downhole conditions. Moreover, a current feedback amplifier LTC1210X of ANALOG DEVICES with extreme high-temperature operation is used as the single-core cable driver for data transmission. Finally, field experiments were conducted, and the results demonstrate the effectiveness of the proposed high-temperature DC-PLC system for the improvement of the efficiency and stability of the downhole system.