Management model for power production from a geothermal field: 1. Hot water reservoir and power plant model

A management model is developed that determines the optimum economic recoverability of a particular hot‐water geothermal reservoir undergoing exploitation for electric power generation. The management model integrates a physical model of the reservoir that predicts the areas of pressure decline due to withdrawals, and pressure rise due to reinjection of spent fluid, with a model of a two‐stage steam turbine power plant that determines the quantity of electricity generated for a rate of hot‐water extraction. Capital costs, variable costs and annual fixed costs are obtained for the reservoir development, extraction and reinjection, the transmission system, and the power plant. Revenues are determined for electrical power production. Application of the management model to a simplified, yet realistic example reservoir demonstrates that the methodology developed in this report can be used for analyzing the management of an integrated geothermal reservoir power plant system. For the example reservoir, 12 potential sites are developed, five for extraction wells and seven for injection wells. The wells on these sites are used to develop up to 27 MW of electrical power over a 20‐year time interval.