What About Geothermal in the U.S. Energy Mix?Production of unconventional oil and gas from shales and sands has afforded North America a mega change in regard to the source and the reliability of supply of hydrocarbons. I often wonder if the latest technologies established to economically produce unconventional gas and liquid from the subsurface — principally hydraulic fracturing and steam-assisted drainage — could transfer to new applications in the geothermal industry. Leveraged by the hydrocarbon industry’s unconventional technologies, could geothermal break through as North America’s next energy resource for large-scale exploration and development? Can and will geothermal energy contribute to North American energy supply with significant impact in the near future and for decades to come? Concern about the security of our domestic energy supply and postulated relationships between global climate change and consumption of fossil and biomass fuels are factors that have contributed to recent expansion of the geothermal industry in the U.S. What is the current U.S. utilization of geothermal energy, and where are U.S. geothermal resources? The Geothermal Energy Association indicates “The United States currently leads the world’s countries in online geothermal energy capacity and continues to be one of the principal countries to increase its geothermal growth. As of April 2010, geothermal electric power generation occurs in nine U.S. states: Alaska, California, Hawaii, Idaho, Nevada, New Mexico, Oregon, Utah, and Wyoming. Other states, such as Colorado, Louisiana, Mississippi, and Texas are soon to be added to the list.” The United States is advantaged with widespread accessibility to domestic “hot rocks”, principally in the Basin and Range and Gulf Coast sedimentary provinces. The land surface used to access and produce energy from hot rocks is small. Also, the energy produced has low emissions, the energy supply is dispatched through the electrical grid and can swing with demand, and the energy resource is sustainable. There are, however, recognized disadvantages to geothermal energy. Groundwater and surface water are expended to transfer heat in geothermal systems, and those waters, through contact with hot rocks, become contaminated with trace amounts of gasses such as carbon dioxide, hydrogen sulfide and methane, and elements such as mercury, arsenic, boron and antimony. Hotspots, the areas in which hot rocks are found, are often associated with geologically recent or active or ongoing tectonic or volcanic activity, thus raising concern and risk for geothermal facilities at the surface.The focus for growth of the U.S. geothermal industry is on fully engineered “conventional” systems where heat mining produces the primary energy to generate hydrothermal energy that in turn produces clean electricity. Enhanced geothermal systems often involve two wellbores, where in the first well, water is injected into the hot host rock, and if not naturally permeable, fractures are hydraulically induced to stimulate fluid saturation and fluid flow. A second well intercepts hot fluid from the fractured rock and circulates the fluid from one well to the other. Another focus of the industry is to produce electricity from “unconventional” or sub-commercial production of hydrothermal fluids which are a co-produced byproduct with oil and gas from wells that tap stratigraphically deep and/or geopressured zones. It is apparent that the oil and gas industry currently employs a workforce with the subsurface skills and access to technologies that will prove vital to moving the hydrothermal industry forward. It is easy to project which petroleum geology and engineering skills and tools are transferable to hydrothermal. The technical specialties are many: stratigraphy and sedimentary petrology; seismic imaging, specifically in hard rocks with faults and fractures; rock mechanics, fracture generation and confined fracture systems; basin modeling, fluid flow, connectivity and pore pressure analysis; high-temperature wellbore geophysics; high-temperature material and fluid engineering; and high-temperature drilling, directional drilling, logging, casing and stimulating. And the list goes on…So the oil and gas industry does have the science and engineering capabilities to grow the geothermal industry, an industry that has recently demonstrated increasing numbers of successes. However, I sense certain challenges attenuate the opportunity for the oil and gas industry to more aggressively tap geothermal resources for economic power generation. I propose the challenges the oil and gas industry needs to overcome include: antipathy, or a lack of knowledge, thought or reason to explore for and develop geothermal resources; and a predilection for the “familiar” hydrocarbon energy. As I believe that geothermal energy has an important niche to fill in the U.S energy mix, I ask that geothermal resources be given an eyes-wide-open look by the oil and gas industry and by our government.