Our earth is a bountiful source of heat. Over the last decade, we have greatly improved our understanding of subsurface heat flow and our ability to engineer systems to exploit geothermal reservoirs. As petroleum reserves become more difficult to replace, alternative energy sources, such as enhanced geothermal systems, hold increasing promise for local and regional use as a renewable and sustainable energy source. In this context we are primarily interested in enhanced geothermal systems (EGS), also known as deep geothermal systems. These are defined as engineered reservoirs where a system of fractures is created in an area with elevated heat, water injected through injection wells, and heat is extracted through production wells.
Much of the know-how and many of the technologies required to develop enhanced geothermal systems are well known in the oil and gas industry. These include operating in a safe and environmentally responsible manner, subsurface imaging and mapping, rock properties under different PT conditions, drilling, creation of fracture zones, injector-producer wells, reservoir management, and project economic stewardship. However, many challenges still exist, including controlled fracture pathways, long term pressure maintenance, and project stand-alone economics and risk assessments.