Abstract
We discuss the emerging Engineered Geothermal Systems (EGS) industry, highlight its significant relationship with the oil and gas drilling industry, and describe overlapping opportunities available for the two industries. EGS refers both to the creation of geothermal reservoirs in deep hot rocks and sedimentary basins, as well as to the unconventional use of co-produced hot water from oil and gas production. It has the potential for transforming geothermal energy from a relatively minor source of baseload electricity production into a resource capable of providing 10 percent or more of domestic US energy needs within a few decades. Traditionally, geothermal has been tied to places with the relatively rare combination of plentiful hot water that is shallow. EGS reservoirs exploit the natural increase of temperature with depth nearly everywhere on Earth. The recovery of just 2 percent of the thermal energy between 3 and 10 km depth in the United States represents about 2,800 times the current domestic energy usage. A modest drilling program of 150 wells per year would provide annual increments of 1,000 to 2,000 MWe. EGS power generation is a readily available domestic source of energy that is reliable, steady, and environmentally friendly. Not only does it emit no greenhouse gases, but there is the potential for CO2 sequestration by mining the geothermal heat with CO2, rather than with water. EGS power plants would require minimal footprints, and waste hot-water from the plant can be exploited for direct-use applications such as manufacturing processes and heating buildings and greenhouses. Drilling rigs, casing, tools, and other typical oil field services have been used to drill geothermal wells. This paper will discuss the level of these services needed for EGS growth, and describe new technologies that must be developed, primarily for the creation of EGS reservoirs.
