Non-Invasive Operations Tool for Dispatchable Geothermal Wells

Geothermal energy is a nearly inexhaustible renewable and clean energy resource. The benefits of geothermal energy include high base load, dispatchability, and long-term stability of geothermal wells under exploitation. However, lack of information on how wells should be properly balanced between production and artificial replenishing puts wells at risk of being over exploited, which can permanently damage the ability of the wells to produce, leading to the incurring of additional cost and the loss of energy resources. Moreover, well information is especially crucial when operating a geothermal plant in a dispatchable mode because changes in well operations performed in accordance with oscillating energy demands could potentially cause even greater damage to exploited wells. We propose a solution for this challenging problem by developing a data fusion algorithm that will serve as an analysis tool for operating current geothermal power plants in a flexible mode. This innovative solution will combine enthalpy measurements from our TRL 6 two-phase mass flow meters with other well performance metrics (such as pressure, temperature, wellhead scaling, power demand, and costs of operation/curtailment of each well) to optimize well operations, thereby enabling geothermal energy to be more widely deployed as a dispatchable electricity source. Phase I key outcomes will be a functioning field-tested prototype sensor that can withstand the harsh conditions of the geothermal surface pipelines for long term deployment, an algorithm that calculates two phase mass flow rates of steam and water using measurements from the sensor, and an algorithm for how the mass flow, enthalpy measurements and other well performance metrics can be used to optimize the efficiency of a dispatchable geothermal plant when operating in flexible mode. In Phase I of this project, we will validate our solution for dispatchable geothermal operations by field testing using our mass flow sensor at operational geothermal wells. We have agreements with two geothermal well owners to host this testing. Mass flow and enthalpy measurements will be taken inline and validated against tracer flow tests (TFTs) conducted by an independent geothermal company. Results of the testing, as well as sample well performance data, will be used to iterate algorithm development until a satisfactory level of thoroughness and accuracy has been reached as validated by an independent geothermal company.