Next-generation advances in subsurface technologies will enable access to more than 100 gigawatt-electric (GWe) of clean, renewable geothermal energy, as well as safer development of domestic oil and gas supplies. The subsurface can also serve as a reservoir for energy storage for power produced from intermittent generation sources, such as wind and solar. As such, understanding and effectively harnessing subsurface resources while mitigating impacts of their development and use are critical pieces of the Nation's forward energy strategy. The Department of Energy's (DOE) Office of Basic Energy Sciences (BES) teams with the Geothermal Technologies Office (GTO) and Office of Fossil Energy and Carbon Management (FECM) in order to advance the state of the art for continued development of subsurface energy sources in a safe and sustainable matter through the focus areas and subtopics listed below. For this topic, the National Energy Technology Laboratory is not eligible to act as a subawardee. Grant applications are sought in the following subtopics: a. Geothermal This subtopic focuses on geothermal systems hosted in sedimentary systems, which directly supports the Biden Administration's goals for a clean energy future. In order to advance the state of the art for such potential geothermal systems, the Department of Energy's Office of Basic Energy Sciences and Geothermal Technologies Office have teamed together to support R&D in the subtopic below. The goal of this subtopic is to advance innovation in development of sedimentary rock formations that may be used to host geothermal systems for purposes of producing electricity. Applications of interest under this subtopic should focus on the challenges related to improving technologies related to geothermal energy development in conditions with elevated temperatures (> 390 F or approximately 200 C) within sedimentary lithologies in order to gain understanding on utilizing sedimentary systems (versus traditional geothermal crystalline systems) for purposes of geothermal energy production. Applications of interest may include, but are not limited to, the following: Novel approaches to characterize subsurface physical and chemical changes in porous rock-fluid systems. Development of new methodologies to understand porosity and permeability trends related to well stimulation. Innovative wellbore designs that focus on utilizing heat contained in sedimentary rock stratigraphy. A Phase I application should focus on proof of concept via engineering design, materials development, modeling, and/or laboratory scale testing (as applicable). Phase I efforts should be scalable to subsequent Phase II development including model validation, prototype development, and/or pilot or field-scale testing (as applicable). Proposed projects with modeling or analysis components could propose analysis of new data sets, existing data sets within the Geothermal Data Repository (GDR) at https://gdr.openei.org/, or other existing data sets. DOE is seeking as much emphasis on open-source data and/or methods as possible. Applications must be responsive to the subtopic of improving understanding of utilization of potential sedimentary resources for purposes of creating electricity from geothermal energy. Applications focusing on crystalline lithologies, conventional ground source heat pumps, traditional direct-use applications, gathering of data via downhole sensors, and conventional usage of geothermal fluids coproduced with hydrocarbons via additional or modification of surface-based equipment will be deemed non-responsive. Questions Contact: William Vandermeer, william.vandermeer@ee.doe.gov b. Development of Wellbore Repair and Remediation Systems for a Gigaton Carbon Storage Industry DOE's Carbon Transport and Storage Program seeks novel, cost-effective wellbore integrity repair and remediation systems. The integrity of wellbores specifically the integrity of casing and materials (cement) used to seal the annulus between the casing and the formations is essential to ensure safe and reliable injection operations as well as long-term containment of CO2 in the targeted reservoir. Wellbore materials must be resistant to chemical corrosion from contacting fluids, be sufficiently strong to withstand mechanical stresses associated with injection, and form complete hydraulic isolation to ensure containment. The acidic nature of carbonic acid (CO2 dissolved into brine) creates a risk unique to carbon storage projects. Carbon steel well components and Portland cements used in conventional oilfield operations can both be breached by the low pH of the fluid. Wellbores potentially requiring repair and remediation include: operating wellbores constructed as part of the development of a storage project; pre-existing wellbores that might be repurposed for injection or monitoring; and abandoned wellbores which may not be easily re-entered, and/or may have been previously plugged and abandoned. Grant applications are sought for the development of an innovative and cost-effective repair and remediation system for commercial use that provides a much higher success rate than the industry standard. The repair and remediation system should include the materials for repair and remediation, the tools to emplace the materials, and tools and methods to assess the integrity of the repair and remediation. Materials must have chemical resistance, strength, and hydrologic properties suitable to enable secure CO2 storage. In addition, materials for repair and remediation of the wellbore annulus must be able to seal a variety of potential CO2 migration pathways from micro- to macro-scale. There are a wide variety of repair and remediation actions, which will likely involve different materials, emplacement, and assessment methods. Grant applications should describe the specific repair and remediation actions which can be performed by the proposed system. Questions Contact: Sarah Leung, sarah.leung@hq.doe.gov c. Turn-Key Service to Create a Geophysical (Electrical and/or Electromagnetic Methods) Monitoring Network for Use During Carbon Storage Site Characterization and/or Carbon Storage Operations The carbon storage program has focused on developing processes and tools that can accurately and affordably assess seismicity risk and CO2 migration risks prior to the CO2 injection phase of a commercial-scale carbon capture and storage operation (>1 million metric tons per year) and/or assess the CO2 plume location after commercial storage operations have started. In the initial phase of a project, there is a strong need to identify natural fracture flow pathways leading into the deeper crystalline basement or into shallower rock layers. The idea is to identify high-risk sites before making large investments in developing the storage project. During the injection of CO2, there is a need to map the location of the plume of injected CO2 within the storage reservoir and identify any CO2 fluid flows into shallower permeable strata where smaller CO2 plumes may form. Recently, DOE's SBIR program solicited turn-key passive seismic monitoring networks and services. Here a new SBIR subtopic solicits for deep subsurface interrogation and geophysical monitoring networks deploying electrical and/or electromagnetic methods, whereby a balance is sought between a fit-for-purpose number and placement of any necessary electric (E) and/or magnetic (B) field sensors along with the sensitivity, frequency range (if applicable), and types of sensors for accurate detection of very weak electrical and electromagnetic field anomalies and CO2 plumes. These networks would include an intelligent level of data processing and streamlined interpretation that does not create a burdensome task for carbon storage project developers and operators. Because geophysical monitoring remains an important factor across the project lifecycle (prior to, during, and after CO2 injection), an additional consideration should be placed on the robust and rugged nature of the system design to support deployment over months to more than 30 years, with an outlook that the system could be updated or upgraded for further use in later phases of the project. Joint inversion of time-lapse seismic data with electrical and gravimetric measurements is widely believed to be a superior method for mapping and quantifying CO2 plumes in sedimentary rock strata. Because injected CO2 may initially push native brines upwards through seal layers into overlying permeable rock layers, the increased electrical conductivity of higher-salinity brines intruding into low-salinity brines could be detectable, even mappable in some cases. Alternatively, interconnected natural fractures in networks extending into the basement may conduct electrical currents into strata that are otherwise more electrically resistive, such that weak EM field anomalies may be detectable. While joint inversion is not within the scope of this subtopic area, the monitoring network should be designed to allow for data acquisition supporting this activity. Grant applications are sought for turn-key systems and services that facilitate easier, better, higher-resolution data acquisition and interpretation of seismicity risks, CO2 migration risks, and/or CO2 plume location(s) using one or more electrical resistivity (ER), magnetotelluric (MT), self potential (SP), and/or electromagnetic (EM natural- or controlled-source) monitoring networks, during the site characterization phase, commercial operations phase, and/or post-injection site care phase, for a broad range of site conditions, either onshore or offshore. To enable this step increase, the goal is to develop a turnkey service that will deliver to the customer a sitespecific monitoring system design, followed by installation of the complete monitoring system, coupled with a tailored level of processing and right-sized data storage and archiving (which is readily accessible by the storage-site developer or operator). Applicants should consider the cost effectiveness of combining more than one electrical geophysics method, and the potential for joint inversion of electromagnetic data with seismic and gravity data (although seismic and gravity methods are not directly within the scope of this subtopic area, nor are the methods of electrical or electromagnetic data interpretation or joint inversions). Sensors or sources can be placed at the land surface or on the sea floor, in shallow boreholes or, on a limited basis, in deep boreholes, and may be deployed in conjunction with other geophysical sensors (e.g., seismic or gravimetric). Sensors may also be towed through the air, across the land surface, or through/upon water bodies. Electromagnetic fields may be induced, and electrical currents may be injected or induced and may be sourced naturally, anthropogenically, or both. Energetic downhole electromagnetic sources that can be deployed in steel-cased wells, fiberglass-cased well sections, or open-hole sections are of interest. Choice of orientation of the monitoring network should account for the orientation of the electrically resistive/conductive features to be assessed. Methods that are minimally disruptive to surface owners and current land use are preferred. Data interpretation may depend on a priori geologic models, borehole data, interpreted seismic data or other constraints; however, the inverse problem must be solvable for a volume of rock large enough to be of value in addressing the concerns identified above for a commercial-scale, geologic CO2 storage complex. The focus of this funding opportunity is not the development of hardware or software; however, hardware and software development can be a small part of the project (a future solicitation may fund such developments further). Nor is this funding opportunity for the development of imaging software; however, this can be a small part of the project. Separately, under the SMART Initiative, DOE is developing methods and software for converting (and jointly inverting) raw to semi-processed data streams in near real time into visualizations of subsurface conditions.
