A Discussion About Fracture Efficiency as a Function of Well Placement with Application to Geothermal Energy

Abstract

Enhanced geothermal systems require fractures to allow water circulation in the artificial underground heat exchanger. The gebo concept focuses on horizontal wells that are connected by multiple fractures. This paper focuses on the optimum positioning of the injector and producer wells as a function of reservoir thickness. For this purpose we define a so called fracture utilization efficiency, which can be used a factor to estimate the proper placement of the two wells. The investigation of well alignment attempts to demonstrate if it is more advantageous to place the production or the injection well above. The development of production temperature shows no differences for the well alignment. The comparison of temperature distribution in the fracture shows of course the upside down effect but the shape and propagation is still the same. Finally we found that the symmetry of the fractures will require 2 producers in order to use the fracture at its maximum efficiency.