Reflecting on 50 years of geothermal innovations

Published: 01/10/2024

SLB Harnessing Geothermal Energy

In 2023, SLB celebrated 50 years of knowledge and expertise in the geothermal industry. While our brand has 100 years of experience for its work in oil and gas, SLB has also had many achievements that have paved the path for the geothermal sector’s growth over the past 50 years—and for its continued growth as the world seeks cleaner energy sources in the years to come. Let’s look at some of these highlights.

The gold standard in consulting services

Our geothermal story accelerated with GeothermEx, a well-known and respected geothermal consulting firm founded in 1973 that we acquired in 2010. Since its inception, GeothermEx built a reputation as the gold standard for geothermal resource assessment and project de-risking. As a result, GeothermEx has supported thousands of geothermal projects in more than 70 countries and been involved in 70% of the world's currently operating projects, producing more than 8.5 GW of the world’s geothermal power.

After our acquisition of the company, we integrated its decades of knowledge and expert services with our broader geothermal portfolio including drilling, well construction, and production capabilities. Combining our knowledge across these disciplines has enabled the development of several geothermal-specific innovations to help improve project economics.

Today, SLB’s GeothermEx™ geothermal consulting services provides customers with geothermal consulting for exploration, development, modeling and optimization throughout the geothermal project life cycle.

Piping from the Northern California Power Agency’s (NCPA) geothermal power plant at The Geysers in the Mayacamas Mountains of Sonoma and Lake Counties in Northern California.
Piping from the Northern California Power Agency’s (NCPA) geothermal power plant at The Geysers in the Mayacamas Mountains of Sonoma and Lake Counties in Northern California.

Digital technology comes of age and improves efficiencies

Reservoir simulators were first developed in the oil and gas upstream industry to offer numerical solutions for fast and accurate prediction of dynamic behavior for all types of reservoirs and development schemes.

SLB’s GeothermEx reservoir engineering experience coupled with SLB’s subsurface workflows and modeling software enabled several advancements in compositional thermal modeling over the past decade. The leading simulator Eclipse™ models two-phase steam-water flow through a reservoir at high flow rates such as observed in geothermal developments. This includes typical two-phase reservoir conditions with countercurrent steam-water flow, well drawdown, cold water injection, and aquifer intrusion.

Software advancements combined with parallel processing and high-performance computing environments have enabled the calibration and development of higher resolution geothermal reservoir models faster than ever.

Together, these advances allow us to conduct more thorough analysis, minimize risks, develop a better understanding of long-term reservoir behavior, and plan developments that protect the long-term sustainability of the resource.

Photo taken at Ormat’s Casa Diablo – CD4.
Photo taken at Ormat’s Casa Diablo – CD4.

Drilling through hard, hot rock more efficiently for better economics

Geothermal wells are typically drilled in high temperature reservoirs characterized by hard, and abrasive formations like igneous and metamorphic rocks, requiring drill bits that can withstand such environments.

SLB developed a bit product specifically designed for these geothermal applications: Kaldera™ roller cone bits. The technology’s seals and grease can extend the bit bearing life in high temperature environments and its optimized cutting structures are designed for hard rock drilling.

Recent studies by the geothermal industry focusing on the reduction of well construction costs have shown that the industry requires a step change in drilling performance, with drilling rates of penetration required to lower the cost per foot drilled and market geothermal projects more economically viable.

This technical challenge is one of the cornerstones that we require for this clean and reliable energy source to reach the promise of geothermal everywhere.

Our drilling data repository containing data from over 1,200 geothermal wells, reveals that historically most wells have been drilled with roller-cone bits. Similarly, oil and gas wells were drilled using roller-cone bits until the development of polycrystalline diamond compact (PDC) bit technology in the 1980s.

Today, most oil and gas wells are drilling using fixed-cutter bits, as these bits have brought substantial improvements to drilling performance. In recent years, the advancement of PDC bit technology, especially in cutter design and manufacturing, have allowed the successful application of this technology in geothermal drilling environments where it was not previously possible.

This has led to considerable improvements in the rate of penetration (ROP), the speed at which the drill bit can break the rock under it thus deepening the wellbore while maintaining durability. Our StingBlade™ PDC bit, with its stinger conical diamond element that point-loads the formation, improves footage drilled and ROP while maintaining great control and minimizing shock in challenging drilling applications. It has been successfully introduced in geothermal environments such as in Indonesia.

Driven by the challenges and recent cost improvement endeavors in geothermal well construction, there is a renewed focus on application-specific cutting structure design. The latest generation of advanced synthetic diamond cutters includes ThermoBlade™. ThermoBlade has thermal-resistant diamond cutting elements that extend cutter life by reducing damage due to thermal degradation. It improves bit performance by maintaining a sharp cutting edge to sustain high levels of ROP, reducing geothermal well construction costs and improving project economics.

Upscaling from agricultural pumps to ESPs to improve production

The primary difference between pumped production in oil and gas and geothermal wells is the need for additional horsepower to support higher flow rates, and thermal resilience and stability to manage the higher temperatures in geothermal wells. Historically, line shaft pumps, which are not specially designed for geothermal wells, have been the dominant artificial lift method in geothermal wells that fail to sustain economically sufficient rates with reservoir energy alone.

Over the last decade, geothermal operators increased their use of electric submersible pump (ESP) technology in lower- and medium-enthalpy wells because of the significant practical benefits over conventional line shaft pumps, establishing a favorable performance record. But so far, ESP technology has found limited use in high-enthalpy geothermal wells, largely due to significant limitations in motor horsepower and, hence, flow capacity.

Major technology breakthroughs in recent decades enabled ESP use in very high temperature environments and more innovation is taking place to develop geothermal technologies from the ground up. For example, the Reda Thermal™ power-efficient geothermal electric submersible pump, which was specially developed for high-enthalpy geothermal wells to deliver elevated flow rates—reliably, efficiently, and with low parasitic load. Today, this technology is helping power plant operators to increase flow rates and boost production reliably and efficiently.

Reda Thermal pump has earned the "Solar Impulse Efficient Solution" Label after a rigorous evaluation process. This label guarantees the economic profitability of products and processes that protect the environment and helps decision-makers find efficient solutions to meet their environmental commitments.

Looking ahead

The examples above showcase some of the innovations that have helped advance the development of once uneconomic geothermal systems and improve the economics of different parts of geothermal project development and operations.

Looking ahead to the next few decades, enhanced geothermal and advanced geothermal systems promise to deliver “geothermal everywhere” or “geothermal anywhere.” To make this a reality, it will require another generation of geothermal-specific technologies in order to make these complex drilling and development projects economic.