Challenges and Recent Advances in Modeling and Simulation of Geothermal Systems

Abstract

Geothermal sites have unique features that require tailored approaches when it comes to production and recovery forecasts. This article explores the latest technologies, and the current challenges that simulation methods face for these types of systems Objectives are to establish this work as a robust literature reference for researchers searching for a guide to assist their future investigations. At the end of their cycles, low permeability hydrothermal sites, low fracture reservoirs, or over-exploited wells are ideal candidates to become enhanced geothermal systems, but to get to this point; optimization processes need to be performed on these sites. Building from earlier models that measure both wellhead temperature and pressure and considering the important challenges to current geothermal systems modeling, we advance a framework that embraces more novel computational techniques that strive towards capturing 3D fluid flow dynamics, as well as potential interactions between aqueous fluids, gases, and porosity and permeability changes brought by the dissolution and transformation of minerals inside the well. The development of more novel models has improved the capabilities for working with increasingly larger quantities of data while also delivering accurate estimations when some data is missing or incomplete. Additionally, the advent of artificial intelligence techniques has aided engineers in modeling quasi-three-dimensional mass transport and fluid flow dynamics, as well as chemical and physical interactions within low-porosity reservoirs. Our review highlights the appearance of two important mathematical models that rely on nonlinear partial differential equations that cover fluid pressure, enthalpy, and boundary conditions. With that said, capturing those interactions in 3D models that are robust and efficient remains a steep challenge for researchers. Through this work, we ultimately offer a roadmap to developing models to combat these limitations. Geothermal systems have been understudied as some consider these wells afterthoughts within oil and gas operations, but more novel methods can significantly improve reservoir simulation for these sites. This work provides a window into the newest advances and techniques while also providing a framework for their use to engineers looking to optimize them.