Electric Submersible Progressive Cavity Pump Combined with Intelligent Composite Coiled Tubing, An Efficient Artificial Lift System for Platform Wells

Recent years, more electric submersible progressive cavity pump (ESPCP) were used in China. Compared with sucker-rod pump, they had outstanding benefits on energy conservation, safety and environmental protection. It needed the sheathed oil-submersible cables tied up outside steel tube to provide power for pumps. But the collisions during running tube and corrosions by well fluid cause serious damages to the cable which is one of the problems for pump inspection. In this paper, ESPCP technology combined with intelligent composite tube was proposed to provide an easy solution of power supply, data gathering and heating function. The tube is constituted of outer covering, structure layer and functional inner layer. The power cables and heating cables are embedded to isolation with wellbore environment. Compared with traditional steel tube, this intelligent composite tube is anti-corrosion, anti-friction, and power cables embedded. It also can be easily operated by special coiled string coiled tubing unit to reduce the operation time. Maximum length of single tube is 2,000 m. Minimum bending radius is 1 m. Work temperature of this composite tube is from −58 to 90 centigrade. Maximum axial tension strength is 200 KN. Maximum internal pressure is 50 MPa. Maximum external pressure is 10 MPa. The heating power is 30 kW. This technology has been successfully applied to four platform wells in Jinlin oilfield, China. The field measured pump efficiency was increased by 33.6% compared to the original pumping unit pump efficiency. The temperature pressure sensor was installed to monitor the temperature of pump output, and control the heating function to prevent the paraffin precipitation caused by low downhole temperature.