Geothermal field development optimization under geomechanical constraints and geological uncertainty: Application to a reservoir with stacked formations

•State-of-the-art stochastic gradient method employed for efficient optimization under uncertainty.•Optimization of well types, locations and production flow rates in case study with stacked reservoir layers.•Achieved significant improvements in terms of the project economics.•Producing different rates from individual stacked geological formations increases performance.•Important to optimize well locations and flow rates to mitigate fault stability risks without compromising performance. In this work, numerical optimization based on stochastic gradient methods is used to assist geothermal operators in finding improved field development strategies that are robust to accounted geological uncertainties. Well types, production rate targets and well locations are optimized to maximize the economics of low-enthalpy heat recovery in a real-life case with stacked reservoir formations. Significant improvements are obtained with respect to the strategy designed by engineers. Imposing fault stability constraints impacts significantly the optimal configurations, with coordinated well rates and placement playing a key role to boost efficiency of geothermal production while keeping stress change effects to acceptable limits.