Conventional artificial lift systems are limited in their application by depth, borehole trajectory, and the produced media's chemistry. This publication presents a performance analysis of the concentric tubular pumping system, which combines the practical concentric tubular completion with the efficient reciprocating hydraulic piston pump to overcome the limitations of existing artificial lift systems cost-effective production for unloading of gas wells and heavy oil recovery. This pumping system consists of a specially designed plunger assembly and barrel combination driven by a hydraulic pressure unit from the surface without any mechanical connection. The hydraulic pump can be circulated into and out of the borehole or run by slick line, resulting in fast and low-cost installation. The pump is designed to run as a concentric tubular pumping system. This paper introduces the pump’s concept, the fluid dynamics simulation, and pump testing at the pump test facility to prove its working principle. The simulations and lab tests have demonstrated very high system efficiencies. The lab tests confirmed the simulation results. At the defined pressure boundary conditions and a speed of 1.5 SPM, a production rate of 9.4 m3/day at a lift efficiency of 95.4 percent was achieved. At 7.6 SPM, the production rate is 100 m3/day, but the system efficiency dropped to 0.25. This pump's unique design requires a low number of moving parts, such as no mechanical connection to the surface and providing minimal exposure to wear and corrosion. Tests have shown that the pump is very adaptable regarding production rate, which requires a change in surface hydraulic pressure, which is typically in a range between 30 and 80 bars. Based on experience, the concentric tubular pumping system is the best selection for unloading gas wells to enhance the completions' lifetime. In This utterly new pump type exceeds the performance of existing artificial lift systems, increases the mean time between failures, and essentially reduces lifting costs.
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