Application of the cable laying coiled tubing in electric submersible pump

摘要

In order to realize the power supply of downhole units without submersible cable, an electric submersible pump (ESP) production technology based on cable coiled tubing was proposed to improve the long-term stability of oilfield production system. The system uses a cable core embedded in the coiled tubing as the power supply line for the downhole submersible motor and power line carrier technology to transmit downhole data to the surface in real time, enabling simultaneous downhole power supply and surface monitoring without the need for additional cables. It has been shown that the wireline coiled tubing can be used in oil Wells at 85°C for a long period of time, and can transmit data up to 2,000 meters downhole with a bit error rate of no more than 10–4 in downhole and other harsh conditions, while the downhole equipment can obtain the rated voltage. Using coiled tubing as the power supply line and communication channel, compared with the traditional ESP system, it can save the downhole space and put more powerful ESP in, thus increasing the production head. The cable core protected by the tubing can also work in the well for a long time to avoid corrosion by the well fluid and ensure the power supply quality of the downhole unit.