Feasibility study of using a downhole pumping system in Menengai well MW-17 for geothermal utilization

Abstract

Utilization of low to moderate enthalpy fluids for electrical power generation is best carried out using a binary energy conversion system. Several technical variations of the binary cycle exist and include the Kalina cycle and the organic Rankine cycle (ORC). The generation of electrical power using pumped brine from well MW-17 is proposed in this report. The utilization scheme consists of an electrical submersible pump (ESP) of 45 kg/s production capacity and an ORC plant. Detailed calculations and optimization using Engineering Equation Solver (EES) software were carried out and show that an ESP of 700 kW tandem motor power is required. In the present study four working fluids (n-butane, isobutene, n-pentane and isopentane) were considered as possible working fluids in the thermodynamic cycle of the binary power plant created in EES and optimized to obtain optimum net power output. An optimum net power output of 832 kW (0.832 MWe) for a turbine inlet pressure of 7 bar using isopentane was indicated by the EES program runs.