Research
and Development Funding OpportunitieS

Topic 6: Adaptive Induced Seismicity Monitoring Protocols

Areas of interest include, but are not limited to:

• Use and integration of existing data sources (for example, DAS, surface and well deployed geophones, injection parameters) to develop hindcast and forecast models for application at Utah FORGE and other locations.
• Applications of machine-learning for operational forecasting.
• Development of improved physics-based protocols for timely operational measures.
• Ability to link injection activity to seismic monitoring results in real-time and propose immediate modifications to the stimulation program.

Targets: Projects proposed under this Topic Area should consider the following and address how the proposed work can meet this target:

• Development of practical real-time adaptive seismicity monitoring protocols that can be tested and validated with existing field test data acquired at Utah FORGE and expanded to other locations.

Field Constraints:

• Methods and technologies that are feasible to implement and compatible with Utah FORGE in-situ monitoring will be considered. Only data that are already available or currently planned for future collection by Utah FORGE should be considered. The deployment of new instrumentation to support this effort is not intended and will not be considered as part of this Topic.

Topic 7: Alternative Stimulation Schemes

Areas of interest include, but are not limited to:

• Stimulation methods including, but not limited to, thermal stressing, chemo-mechanical weakening, energetics (propellants and HE), cycling rates, and chemical stimulation.
• Novel drilling techniques such as wishbone completions and slimhole branches that facilitate increased reservoir access.

Targets: Projects proposed under this Topic Area should consider the following and address how the proposed work can meet this target:

• Stimulation methods that establish multiple fluid flow paths that permeate the reservoir volume between the injection and the production wells and that avoid short-circuiting of flow via a limited number of these paths.

Field Constraints:

• Methods and technologies that are feasible to implement, compatible with Utah FORGE in-situ conditions, and deemed safe for deployment in the Utah FORGE wells will be considered; however, technologies may be deployed in wells other than the Utah FORGE wells at the discretion of DOE and Utah FORGE or as proposed by the applicant.
• Methods must be contained within a defined section of the wellbore and pass through or be implemented in a 7-inch diameter casing.
• Methods must consider the placement of the treatments and its impact on the completion hardware and address operational or engineering issues associated with the stimulation scheme.

Topic 8: Field-scale Experiments to Measure Heat-sweep Efficiency

Areas of interest include, but are not limited to:

• Novel tracer and geochemical studies directed at understanding fluid/fracture contact area over time.
• Geochemical analysis.
• Pressure transient analysis and interference testing.
• Production and/or temperature logging (in support of methods that do not rely on thermal breakthrough for prediction).
• Remote imaging techniques.
• Specially designed injection/production sequences, such as circulation at different rates/pressures or huff/puff.

Targets: Projects proposed under this Topic Area should consider the following and address how the proposed work can meet one or more of these targets: 

• Collection, interpretation, and analysis of data that supports the prediction of reservoir thermal performance without solely relying on the long-term production temperature data.

Field Constraints:

• Methods and technologies that are feasible to implement; compatible with Utah FORGE in-situ conditions, infrastructure, schedule, and operational envelope; and deemed safe for deployment in the Utah FORGE wells will be considered.

Topic 9: Stimulation and Configuration of the Well(s) at Utah FORGE High Temperature Proppants

Areas of interest:

• The development and demonstration of proppants for improved fracture conductivity support capable of reliable long-term performance in hot aqueous environments with extended thermal/cycles, and field testing at the Utah FORGE site or other location (pending approval of Utah FORGE).
• The development of tagged proppants that can be used to support remote mapping, emplacement efficiency of treatments, locations of created fractures and/or the flow of fluids through the EGS reservoir.
• Development of taggant materials that can be applied to proppants intended for long-term reliability.

Targets: Projects proposed under this Topic Area should consider the following and address how the proposed work can meet one or more of these targets:

• Proppants intended for long-term conductivity support (minimum of 5-year design life) and thermal/pressurization cycles (150 to 250°C and 35 to 70 MPa respectively) in hot aqueous brines (250°C and 10,000 TDS) to demonstrate acceptable long-term fracture conductivity at the flow conditions experienced at the Utah FORGE site.
• Proppants tagged with a material that can support reservoir characterization following emplacement with operational use for extended periods (minimum of 1-year design life) and thermal/pressurization cycles (150 to 250°C and 35 to 70 MPa respectively) in hot aqueous brines (250°C and 10,000 TDS).
• Laboratory testing following ISO Standard 19B (API RP 19D) across temperatures and pressures noted above using plates made of Sierra White or Westerly granite. Minimum of 50-hour testing.
• Capability for manufacturing sufficient quantities of proppant for field trial at the Utah FORGE or other site at the discretion of Utah FORGE.

Topic 10: Multiset Straddle Packers for Open Hole Operations

Areas of interest include:

• The development and demonstration of field-tested reliability at the Utah FORGE site of multiset straddle packers suitable for operational use at temperatures at or greater than 225°C for extended periods and thermal/pressurization cycles in hot aqueous fluids typical of geothermal fluids (typically < 10,000 TDS).

Targets: Projects proposed under this Topic Area should consider the following and address how the proposed work can meet these targets: 

• Capable of operation without being damaged at operational temperatures in the presence of aqueous brines (10,000 TDS) at or greater than 225°C for two weeks, after cycling for 8 times under 5000 psi differential pressures.
• Development of a deployment ready multiset straddle packer assembly capable of at least 6 sets in a borehole diameter of 9-1/2 inches and representative derivative designs for operations at diameters of 5-1/2 inches to 12-1/4 inches.
• Upper packer of the straddle system should be capable of operating as a single, stand-alone packer.
• Variable straddle length up to 100 feet.
• The differential between the packer pressure and test interval pressure should be controllable by the operator.
• Mitigations to address potential issues of tubing loading on packer assembly during deployment.
• Field demonstration of the packer system at conditions representative of the targets above.
• Packer system must seal in oval hole with the short dimension equal to bit gage diameter, and the long dimension 1/2″ greater than bit diameter.
• Packer system must pass through irregular borehole features created by the drilling steering system that are 3/8″ under gage to the bit diameter, without damage.
• Packer system must pass through a radius of curvature in the build section of a directional well of 6 degrees per hundred feet, without damage from slide-loading forces or contact.

Field Constraints:

Methods and technologies that are feasible to implement and deemed safe for fielding at Utah FORGE or other locations. Location to be determined in consultation with Utah FORGE.

Topic 1: Devices suitable for sectional (zonal) isolation along both cased and open-hole wellbores under geothermal conditions

Areas of interest include, but are not limited to:

• Development of a field-scale device, system, or process that can isolate specific intervals along the wellbore, for long-term injection and production, at initial and full operation in situ pressure, temperature, and flow conditions, in either casing of a given casing Internal Diameter (ID) or an open hole over a range of IDs expected in the Utah FORGE injection and production wells
• External casing isolation devices/systems in addition to wellbore cements that support zonal isolation in EGS environments.

Targets: Projects proposed under this Topic Area should consider the following and address how the proposed work can meet one or more of these targets:

• Operational at 225oC for extended periods and thermal/pressurization cycles to demonstrate acceptable leak rates at design pressures defined by the applicant for diameters > 7 inches (17.8 cm).
• Retrievable after a performance period of at least 12 months for systems intended to be retrievable.
• Capable of operation without being damaged by the flow of fracturing fluid that contains proppant.

Existing Data Resources:

1. Selected Utah FORGE GDR data sets
   • Well 58-32 injection tests
   • Well 58-32 injection test packer performance
   • Well 58-32 core analyses
   • Utah FORGE rock properties
2. Selected Utah FORGE Reports and Publications
   • Section B of the Phase 2C Topical Report
   • UGS Miscellaneous Publication 169
   • For reference, please find the DOE Funding Opportunity Announcement focused on Zonal Isolation here: DE-FOA-0001945 (Zonal Isolation for Manmade Geothermal Reservoirs)

Topic 2: Estimation of stress parameters

Areas of interest include, but are not limited to:

• Using complementary and established techniques to characterize the 3D in situ stress state in the Utah FORGE reservoir, including variations in principal stress orientations and magnitudes with depth.
• Analysis of existing Utah FORGE data and contributing to the development of stress measurement protocols for the next phase of stress characterization performed by the Utah FORGE team or performed by the awardee alongside the Utah FORGE team.
• Utilizing combinations of diagnostic fracture injection tests (DFITs), minifracs, high-quality wireline geophysical logs (including image logs), physical properties testing on recovered core, borehole failure analysis, analyses of earthquake source parameters and other data (respecting varying length scales of different measurement approaches) to characterize the 3D in situ stress state in the Utah FORGE reservoir.
• Quantification of stress heterogeneity and associated impact on fracturing processes, including data that are proximal and distal to the borehole, to characterize/constrain variations in the in-situ stress field within the reservoir volume.

Targets: Projects proposed under this Topic Area should consider the following and address how the proposed work can meet one or more of these targets:

• Uses at least one technique that is complementary to the analysis of DFITs performed at Utah FORGE at three or more locations to inform all three principal stress orientations and magnitudes.

Existing Data Resources:

1. Selected Utah FORGE GDR data sets
   • Well 58-32 injection tests
   • Well 58-32 core analyses
   • Utah FORGE rock properties
2. Selected Utah FORGE Reports and Publications
   • Section B of the Phase 2C Topical Report
   • 2020 Stanford Geothermal Workshop paper (Xing et al., 2020)
   • UGS Miscellaneous Publication 169

Topic 3: Field-scale characterization of reservoir stimulation and evolution over time, including thermal, hydrological, mechanical, and chemical (THMC) effects

Areas of interest include, but are not limited to:

• Monitoring the growth of the stimulated volume over time using broadband seismic, strain, and additional geophysical techniques. Data can be acquired with downhole and surface instruments.
• Evaluating the relationship between seismic/aseismic deformation and resulting changes in reservoir permeability.
• Assessing poro-thermo-hydro-mechanical properties controlling the source characteristics and frequency magnitude distribution of induced seismicity.
• Understanding of THMC properties as they impact reservoir performance (e.g., fluid flow, heat extraction, and sustainability).
• Utilization of natural and introduced tracers, geochemical monitoring, remote sensing, geophysical imaging (e.g., EM, ERT, seismic, etc.) and their integration to evaluate reservoir stimulation, growth, and temporal evolution.
• Monitoring, acquisition, and interpretation of new and existing Distributed Acoustic Sensor (DAS) data.

Targets: Projects proposed under this Topic Area should consider the following and address how the proposed work can meet one or more of these targets:

• Measurement of parameters such as seismicity, temperature, pressure, strain, and fluid chemistry (e.g., pH, chloride, and conductivity at a minimum) within the reservoir (includes downhole measurements as well as surface-based measurements) during stimulation, shut-in, flow-back, and operations, to inform field-scale characterization of reservoir stimulation and evolution over time.
• Integration of multiple data streams, including direct downhole measurements and inferences based upon other observations.
• Characterization of earthquake source mechanisms (e.g., failure mode, stress drop, and focal mechanisms) and location precision (10 m or less), with recordings with bandwidth between 0.001 Hz and 1 kHz.
• Successful deployment and running of sensors capable of withstanding 225°C borehole conditions for at least 12 months.

Field Constraints

• Wells 58-32 (~7,500 feet total depth) and 78-32 (~3,300 feet total depth) are available for deploying downhole sensors both during and outside periods of stimulation. A third well (Well 56-32, expected depth ~4,500 feet) is planned and should be available when awards are made under this solicitation.
• Well 68-32, drilled to approximately 1,000 feet, has dedicated seismic sensors emplaced and cannot be re-entered. Data from the well will be available.
• Surface sensors can be deployed in and around the Utah FORGE site, extending on to BLM land with minimal restriction, as long as there is no subsurface disturbance to greater than 0.5 m depth.
• There are no samples of fluids and pore waters from the reservoir. We expect flowback waters to be collected during the stimulation experiments that follow the drilling of the first deep well.

Existing Data Resources:

1. Selected Utah FORGE GDR data sets
   • Schlumberger microseismic data detected during Phase 2C stimulation
   • InSAR data Phase 2C ground deformation monitoring
   • Well 58-32 injection tests
     
2. Selected Utah FORGE Reports
   • Phase 2C Topical Report
   • Phase 2B Topical Report

Topic 4: Stimulation and configuration of the well(s) at Utah FORGE

Areas of interest:

• An innovative implementation of current technologies or development of new technologies for reservoir stimulation at Utah FORGE that must:
  1. Consider the optimized placement of the future production well in respect to the geometry of the stimulated reservoir and sustained heat transfer.
  2. Address operational or engineering methods to overcome/mitigate impacts of stress heterogeneity, anisotropy, and stress shadowing as part of the stimulation approach.

The proposed stimulation designs should be optimized based on in situ reservoir data, including stress fields and pre-existing fractures, especially those that may cross lithological boundaries. The applicant will collaborate and coordinate with Utah FORGE closely during the deployment of the proposed stimulation approach. Furthermore, the applicant will be expected to share their analyses to the Utah FORGE team and collaborate on identifying the ideal placement and completion of the production well to provide optimal stimulated geometry and heat transfer to the circulating fluid.

Targets: Projects proposed under this Topic Area should consider the following and address how the proposed work can meet one or more of these targets:

• Stimulation methods that establish multiple fluid flow paths between the injection and the production wells and that avoid short-circuiting.
• Methods and technologies that are feasible to implement, compatible with Utah FORGE in situ conditions, and deemed safe for deployment in the Utah FORGE wells will be considered; however, technologies may be deployed in wells other than the Utah FORGE wells at the discretion of DOE and Utah FORGE (e.g., sites selected as Wells of Opportunity in DE-FOA-0002227).
• Methods must be contained within a defined section of the wellbore and pass through or be implemented in a 7-inch diameter casing.

 Supporting modeling:

1. Models should employ a predictive approach that analyzes different well alignments, informed by microseismic and other data from field monitoring, robust 3D characterization of the target formation, and an understanding of the relative influence of in situ conditions and evolution of in situ conditions over time on reservoir performance.
2. Models are expected to include sensitivity studies covering:
   • A range of well geometries
   • Uncertainties in geology, structure, and stress gradients/heterogeneity
   • Completion strategies
   • Alternative stimulation plans (rates, volumes, interval spacings, etc.)
   • Predictions of seismicity ahead of stimulation.

Existing Data Resources:

1. Selected Utah FORGE data sets
   • Well 58-32 injection tests
   • Well 58-32 core analyses
   • Rock properties
   • Phase 2 earth model
2. Phase 2 Numerical Model data
   • Phase 2 numerical model
   • Numerical model mesh files
   • Numerical model boundary and initial conditions
   • Native state model results
   • Planned trajectory for first Utah FORGE deviated well
3. Selected Utah FORGE Reports
   • Section B of the Phase 2C Topical Report
   • 2020 Stanford Geothermal Workshop paper (Podgorney et al., 2020)
   • 2020 Stanford Geothermal Workshop paper (Finnila and Podgorney, 2020)
   • 2020 Stanford Geothermal Workshop paper (Xing et al., 2020)
   • UGS Miscellaneous Publication 169

Topic 5: Integrated Laboratory and Modeling studies of the interactions among THMC processes

Areas of interest include, but are not limited to:

• Measurement of physical and mechanical properties and their anisotropy (e.g., permeability, thermal expansion coefficients, and poro-elastic constants as a function of temperature) relevant to modeling the response of the EGS rock mass.
• Evolution of the unperturbed reservoir and response to stimulation and heat extraction over time.
• Integrated laboratory/modeling work that includes:
  1. Permeability changes along a shear fracture and subsequent temporal evolution due to physical and geochemical processes at EGS conditions, with model evaluation of field implications
  2. Studies of the frictional/deformational behavior of faults and natural fractures relevant to FORGE reservoir conditions to characterize stimulation behavior, including fluid pressure thresholds for stimulation and partitioning between seismic and aseismic deformation
  3. Time dependence of poro-elastic response of fractured/unfractured media due to thermally and/or mechanically induced stress changes
  4. Produced-water chemical changes that could be indicative of changes in reservoir properties and flow paths over time; laboratory experiments should be compared to field data.

Targets: Projects proposed under this Topic Area should consider the following and address how the proposed work can meet one or more of these targets:

• Determination of relevant properties and processes to support modeling of reservoir performance at 150°C-250°C under realistic stress and lithologic/geochemical conditions.
• Quantifiable reduction in the number of estimated inputs to numerical models and/or simulations of FORGE reservoir performance and implications on overall uncertainty.
• Demonstrated use of THMC coupled models related to fracture creation, interactions with natural fractures, permeability changes, and heat transfer to understand reservoir performance and to guide possible interventions for optimal heat extraction.
• Quantification of coupled processes related to permeability gain and loss that inform a successful modeling-informed application of reservoir engineering using the Utah FORGE site as the test case.

Existing Data Resources:

1. Selected Utah FORGE data sets
   • Well 58-32 injection tests
   • Well 58-32 core analyses
   • Rock properties
   • Phase 2 earth model
2. Phase 2 Numerical Model data
   • Phase 2 numerical model
   • Numerical model mesh files
   • Numerical model boundary and initial conditions
   • Native state model results
   • Planned trajectory for first Utah FORGE deviated well
3. Selected Utah FORGE Reports
   • Section B of the Phase 2C Topical Report
   • 2020 Stanford Geothermal Workshop paper (Podgorney et al., 2020)
   • 2020 Stanford Geothermal Workshop paper (Finnila and Podgorney, 2020)
   • 2020 Stanford Geothermal Workshop paper (Xing et al., 2020)
   • UGS Miscellaneous Publication 169