Evaluation of the Advantages of Multilateral Closed Deep Geothermal Frameworks Over Conventional Geothermal Systems

Abstract

Operating with typical geothermal systems may create seismic events, contaminate subsurface water, and cause other environmental hazards. However, multilateral closed deep geothermal systems can extract a considerable amount of energy in an environmentally friendly manner. Nevertheless, generated power, predictability, longevity, and payback period of these systems are controversial among scientists. Therefore, the primary purposes of this study can be categorized into three main groups: evaluation of the impact of operational parameters and system configuration on outputs, prediction of system's long-term behavior, and identification of the common features of high-performance MCDG systems. The findings of this study revealed that operating with MCDG systems doesn't always result in higher performance than simple closed deep geothermal systems. However, their longevity is much better than conventional open geothermal frameworks. Moreover, high-performance MCDG systems are distinguished by a specific relation between total flow rate and the number of injection/horizontal wellbores. Finally, it is found that the long-term performance of MCDG systems (i.e., extraction temperature and generated thermal power) is predictable as a function of their short-term behavior.