Renewable Spotlight: Geothermal Energy
Posted on July 6th, 2021
Posted in Uncategorized
What is Geothermal Energy?
Geothermal energy is an always-on, renewable energy source that harnesses the heat energy of the earth’s interior. It made up about 0.4% of the United States’ 4 trillion kWh total electricity generation in 2020. Besides electricity generation, geothermal can be used for heating and cooling of homes. The focus of this article will be geothermal electricity production and how it may impact the oil and gas industry.
Geothermal Basics
Geothermal electricity generation usually utilizes the same kinds of steam turbines as can be found in a typical coal-fired power plant. The difference is that instead of burning coal to boil water and produce steam, geothermal plants harvest the heat from within the earth to produce steam (although other working fluids can be used).
The earth has a natural geothermal gradient, and those familiar with subsurface principles probably know that gradient is nominally 1-2 °F per 100’ for on shore US oil and gas fields. Simplified, this means that the deeper a well is drilled, the hotter the rock around it will be.
In addition to a natural geothermal gradient, there are also hotspots known as geothermal reservoirs. Geothermal reservoirs are not widely distributed, and mostly occur near the boundaries between tectonic plates. Some well-known geothermal reservoirs are found in California and Iceland, which each sit on top of tectonic plate boundaries.
Oil and Gas Technologies in Geothermal
A number of technologies and disciplines that are already implemented day-to-day in the oil and gas industry also apply to geothermal power generation. Traditionally, geothermal power plants have been located near geothermal reservoirs since the temperatures are much hotter and the heat flux much higher than elsewhere. But developing and innovative technologies suggest if you drill deep enough and over a large enough area, geothermal power heat requirements can be met even in the absence of a geothermal reservoir.
Directional drilling, hydraulic fracturing, reservoir management, and water will be key disciplines that are involved in developing geothermal fields.
Directional drilling in combination with hydraulic fracturing will allow for development of large networks of wellbores deep underground. Hydraulic fracturing will increase the surface area of the earth that the wellbore has access to. Maximizing this surface area will be required to harvest the amount of heat required to supply the plant given the lower heat flux the earth provides in absence of a geothermal reservoir.
Reservoir management will play a role in ensuring the heat harvested from the geothermal field is in balance with the heat able to be supplied from deeper within the earth.
Water injection will be required to harvest the earth’s heat from deep below and transport it to the surface. Analogous to the water flooding of enhanced oil recovery (or solution mining of salts), water will be injected in one location, heated by the earth, and be brought to surface at the power plant where it can be used to generate steam (or vaporize another working fluid) for a turbine cycle.
Outlook
Although geothermal energy only made up 0.4% of the 2020 US total electricity production, its share is expected to grow. This is because geothermal energy eliminates one of the largest challenges facing renewable energy sources such as wind (8.3%) and solar (2.3%): intermittency. The solution to wind and solar intermittency (when the wind isn’t blowing or the sun isn’t shining) is an area of active research and development for those technologies.
As each technology works to address its own challenges, the biggest drivers for the future will likely be cost effectiveness and volume of investment (typically spear headed through government subsidies). Although it is difficult to predict, it seems geothermal will be at the forefront as we in the energy industry continue to innovate to meet growing demand. At Halker, we have built a highly qualified geothermal team enabling our customers to maximize the potential of their resources.
Andrew Depperschmidt is a graduate from the Colorado School of Mines with a Bachelor of Science in Engineering Physics and a Master of Science in Mechanical Engineering. He has experience in a variety of construction and facilities projects including both upstream and midstream natural gas and crude oil processing. He joined Halker in January of 2015 as the Mechanical Department Manager and has since taken on several different responsibilities with the firm, including General Manager and Vice President. Over the course of his time with Halker, he has overseen the company’s growth, helped develop the management team, and helped structure operational processes around project execution for maximum quality. He’s inspired by Halker’s outstanding team daily and takes pride in being people-focused while driving the company’s progressive and forward-looking culture. 
Kathryn Goodman graduated from Texas A&M University with a Bachelor of Science in Mechanical Engineering in 2011. She is a licensed professional engineer in the state of Texas and brings over a decade of mechanical and pipeline engineering experience to her role. Throughout her career, Kathryn has worked on both small and large-scale oil and gas projects in the upstream, midstream, and downstream sectors.
Jeff Wellen graduated from the Colorado School of Mines with a Bachelor of Science in Mechanical Engineering and a minor in business and economics in 2002. Jeff is a licensed professional engineer with over 22 years of project management, project engineering, and mechanical engineering experience. Most of his professional career has been in the Oil & Gas industry with a wide range of experience across various types of projects including gas treating, LNG, well pad sites, cryogenic processing, biofuels, and more. He has also worked as a field engineer to support construction, as well as in a fabrication shop to oversee module/pipe-rack assembly. As a member of the Halker team since January 2018, his breadth of involvement in various projects provides Jeff a strong basis to provide operation execution support for successful project execution teams through the trials and tribulations when executing any type of project ranging from technical studies to full EPC projects in the rapidly evolving midstream and upstream industry sectors. Jeff was named an Engineering News Record (ENR) Top Young Professional in 2018 for the Mountain States Region.
Jeremy Montoya graduated from the Colorado School of Mines with a Bachelor of Science in Engineering with an Electrical specialty focus in 2010. Jeremy is a licensed professional engineering in multiple states and has over 14 years of experience in consulting engineering and has working in nearly every sector or the business, from oil and gas to food and beverage, mining, pharmaceuticals, commercial and residential applications. Jeremy joined Halker in 2021 and has brought a passion to build up and support staff as they provide quality engineering and design services to every client we have the opportunity to work with. With an eye for detail, value and confident support- our EI&C group will continue to grow and be recognized for their expertise, attentiveness, and quality deliverables in every project. Jeremy has also volunteered engineering services abroad, helping with the design of water/wastewater treatment facilities and medical facilites in Kenya, as well as master plans for facilities in Mexico.
Austin Dean graduated from Colorado School of Mines in Chemical and Biochemical Engineering. He has experience in engineering design projects for well pad facilities, gathering systems, and midstream natural gas facilities. Starting his career at Halker in 2014, his roles and responsibilities have spanned Process Engineering, Project Engineering, Project Management, and Facilities Engineering. He specializes in jet pump artificial lift surface facilities and dynamic hydraulic modeling. Austin brings an E&P perspective to the Halker team, with a focus on project economics and larger implications of design decisions.
Paul Brennan is an industrial automation specialist, PLC programmer, business manager and product development professional. He graduated from Colorado Mesa University in 1992 with a Bachelor of Science in Computer Science. Paul now has over 25 years of experience providing industrial automation solutions and large-scale automation integration projects for oil & gas, water/wastewater, irrigation, and greenhouse industries in the US and Eastern Europe. Paul’s career has been spent developing leading edge, revolutionary automation products, and in the process, he has obtained several US Patents. Paul has notably designed products such as PADPro, PADManager, PROView and QLogiX for upstream oil & gas facilities, utilizing state of the art technologies with PLC’s and high-powered single board computers to provide advanced data collection and data processing at the well head.