DEEE0010445

Evaluation of Physics-Based Drilling and Alternative Bit Design at The Geysers

The long-term goal of the project is to safely implement oil and gas industry drilling best-practices, particularly with respect to limiter-redesign. These approaches to improving processes have been proven to enable step-change performance compared to incremental performance improvements based on empirical data or conventional wisdom.

As a geothermal developer, operator, and power producer, Geysers Power Company (GPC) is uniquely positioned to implement these fundamental changes to the way geothermal energy is produced. To achieve the long-term goals, the proposed project will work towards meeting the following objectives:

Objective 1: Identify and understand process limiters from historical drilling data. Previous drilling campaigns at The Geysers have followed conventional drilling techniques. The resulting rate of penetration (ROP) has typically been on the order of 10's ft/hr. Evaluating the previous data to identify process limiters such as reluctance to apply additional weight on bit (WOB), will be critical to understanding where improvements can be made.

Objective 2: Establish workflow for implementing limiter redesign for upcoming drilling campaigns. The team will implement limiter redesign workflows into the project planning and execution. Lessons learned from the Utah Frontier Observatory for Research in Geothermal Energy (FORGE) indicate the following areas must be addressed to be successful when embracing new methodologies and approaches, particularly with respect to drilling:
1. Relationship with bit vendor and established contingencies defined prior to drilling.
2. Protocols for evaluation – this include WOB and rotary speed (RPM) step tests – sometimes we don't see the physics clearly.
3. Methods for analyzing performance – such as mechanical specific energy (MSE), drilling strength (DS) or combinations that allow us to identify dysfunction and limiters.
4. Plans for how to overcome these issues.
5. Engage management to support implementing limiter redesign workflows.

Objective 3: Adopt modern bit technology and utilize in upcoming drilling campaign. Technological advancements in bit construction played a role in the performance gains witnessed at Utah FORGE. Changes such as shaped cutters, cutter chamfers, and cutter diameter modifications have enabled maximizing WOB application to the bit. These techniques have proven to be successful when combined with a physics-based limiter redesign approach to operations. The team will work with vendors to develop or modify polycrystalline diamond compact (PDC) bits for drilling in the production zones.

The Geysers historically has required air drilling in the production zone due to fractures and the resulting lost circulation. Another element of the proposal is to evaluate the effectiveness of PDC bits with air drilling. The team will seek to identify process limiters associated with lost-circulation drilling and compare them with the limiters associated with mud/water drilling.

Objective 4: Implement advanced control strategies to reach limits based on electronic drilling records (EDR) data analytics. Step tests of both WOB and RPM are the basic diagnostics used to identify limiters in the drilling process. This is largely a manual process in which WOB or RPM set points are stepped in increments while mechanical specific energy response is monitored. Sandia has intellectual property (U.S. Patent #11280173) related to executing the process optimization in a more informed manner. The concept has been demonstrated in a lab-drilling environment but has not been field-tested. A portion of the proposed work will seek to deploy the control algorithm as part of the drilling demonstration.

Objective 5: Promote diversity, equity, inclusion (DEI), and growth in the broader geothermal industry. To foster continued progress in DEI, the team will engage in community outreach efforts targeting underrepresented groups. GPC will provide tours and site visits to organizations which provide skills to youth and young adults in frontline communities with an emphasis on environmental protection, justice, and economic development. Additionally, the team will identify and engage minority-owned, women-owned, and veteran-owned businesses when soliciting bids.

The drilling campaign will be conducted in Sonoma and Lake Counties in California. GPC uses local labor as available to complete and conduct operations which will create job opportunities for clean energy development. Additionally, the planning and execution of a high-profile drilling demonstration will bring attention and opportunities to these areas.

GPC is a leader in the geothermal industry. Advances that are made at organizations like GPC can set the stage for what the entire industry can do. Use of PDC bits has been largely confined to controlled demonstration projects. The technology adaptations for geothermal formations are in the nascent stages, but additional demonstrations of proven performance will generate additional support from vendors and suppliers leading to an expanding base. Ultimately, enacting lasting change will have benefits for the entire industry and increase access to clean, renewable energy for all.

Geysers Power Co

THIS FOA TARGETS TECHNOLOGY DEVELOPMENTS THAT WILL PROVIDE SIGNIFICANT IMPROVEMENTS IN DRILLING PERFORMANCE IN COMMERCIAL GEOTHERMAL SETTINGS. THE GEOVISION ROADMAP2 OUTLINES A COMPILATION OF TECHNICAL, ECONOMIC, AND INSTITUTIONAL ACTIONS THAT THE ENTIRE GEOTHERMAL COMMUNITY, INCLUDING DOE, INDUSTRY, AND ACADEMIA MUST ADDRESS IN ORDER FOR GEOTHERMAL TECHNOLOGIES TO PLAY A LARGER ROLE IN THE NATION’S ENERGY MIX.

81.087 - Renewable Energy Research and Development

Golden Field Office (GFO) [DOE - EERE]

Office of Energy Efficiency and Renewable Energy (EERE) [DOE]

Middletown, California United States

City-Wide

Geothermal Drilling Technology Demonstration Campaign (GDTDC) (DE-FOA-0002656)

Amendment Since initial award the End Date has been extended from 11/30/24 to 11/30/25.