NOFO_DE-FOA-0003630_UNLOCK.pdf

Questions about this NOFO? Check the Frequently Asked Questions available at https://arpa-e.energy.gov/faqs.

For questions that have not already been answered, email ARPA-E-CO@hq.doe.gov (with NOFO name and number in subject line). Problems with DOE eXCHANGE? Email ExchangeHelp@hq.doe.gov (with NOFO name and number in subject line).

FINANCIAL ASSISTANCE

NOTICE OF FUNDING OPPORTUNITY

ADVANCED RESEARCH PROJECTS AGENCY—ENERGY (ARPA-E)

U.S. DEPARTMENT OF ENERGY

UNLOCKING NEW LEVELS OF OUTPUT AND CAPACITY

FOR KEY SUBSURFACE RESOURCES (UNLOCK)

Announcement Type: Initial Announcement

Notice of Funding Opportunity No. DE-FOA-0003630

Assistance Listing Number 81.135

NOFOs are posted on DOE eXCHANGE

(https://exchange.energy.gov/Default.aspx?Org=ARPA-E), grants.gov (http://www.grants.gov/), and FedConnect (https://www.fedconnect.net/FedConnect/). Any modifications to the NOFO are also posted to these websites. You can receive an email when a modification is posted by registering with FedConnect as an interested party for this NOFO. It is recommended that you register as soon as possible after release of the NOFO to ensure that you receive timely notice of any modifications or other announcements.

https://arpa-e.energy.gov/faqs mailto:ARPA-E-CO@hq.doe.gov mailto:ExchangeHelp@hq.doe.gov https://exchange.energy.gov/Default.aspx?Org=ARPA-E http://www.grants.gov/ https://www.fedconnect.net/FedConnect/

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AR-311-05.25

TABLE OF CONTENTS

BASIC INFORMATION.......................................................................................................... - 6 -

I. FUNDING OPPORTUNITY DESCRIPTION .............................................................. - 8 -

A. AGENCY OVERVIEW ........................................................................................................ - 8 -

B. PROGRAM OVERVIEW ..................................................................................................... - 9 -

1. BACKGROUND AND MOTIVATION .............................................................................. - 9 -

2. TECHNICAL CHALLENGES ....................................................................................... - 11 -

C. PROGRAM OBJECTIVES ................................................................................................. - 15 -

D. TECHNICAL CATEGORIES OF INTEREST ....................................................................... - 15 -

1. TECHNOLOGIES OF INTEREST ................................................................................. - 15 -

2. SUBMISSION AND TEAM LOGISTICS ......................................................................... - 16 -

E. TECHNICAL PERFORMANCE TARGETS ......................................................................... - 17 -

1. CATEGORY A: SHALE AND TIGHT OIL & GAS ......................................................... - 17 -

2. CATEGORY B: OTHER LOW-PERMEABILITY SUBSURFACE RESOURCES ................. - 20 -

F. STATEMENT OF SUBSTANTIAL INVOLVEMENT ............................................................. - 22 -

G. FUNDING RESTRICTIONS ............................................................................................... - 23 -

1. ALLOWABLE COSTS ................................................................................................. - 23 -

2. PRE-AWARD COSTS ................................................................................................. - 23 -

3. PATENT COSTS ........................................................................................................ - 23 -

4. CONSTRUCTION ....................................................................................................... - 23 -

5. FOREIGN TRAVEL .................................................................................................... - 24 -

6. PERFORMANCE OF WORK IN THE UNITED STATES.................................................. - 24 -

7. PURCHASE OF NEW EQUIPMENT ............................................................................. - 24 -

8. TECHNOLOGY TRANSFER AND OUTREACH .............................................................. - 24 -

9. LOBBYING................................................................................................................ - 25 -

10. CONFERENCE SPENDING ......................................................................................... - 25 -

11. INDEPENDENT RESEARCH AND DEVELOPMENT COSTS ........................................... - 25 -

12. BUY AMERICA REQUIREMENT FOR PUBLIC INFRASTRUCTURE PROJECTS .............. - 26 -

13. REQUIREMENT FOR FINANCIAL PERSONNEL .......................................................... - 26 -

14. PARTICIPANTS, COLLABORATING ORGANIZATIONS, AND CURRENT AND PENDING

SUPPORT ............................................................................................................................ - 26 -

15. PROHIBITION ON THE USE OF FUNDS FOR ACTIVITIES RELATED TO FASC-

PROHIBITED UNMANNED AIRCRAFT SYSTEMS .................................................................. - 27 -

II. ELIGIBILITY INFORMATION .................................................................................. - 28 -

A. ELIGIBLE APPLICANTS .................................................................................................. - 28 -

1. INDIVIDUALS ........................................................................................................... - 28 -

2. DOMESTIC ENTITIES ............................................................................................... - 28 -

3. CONSORTIA.............................................................................................................. - 29 -

4. FOREIGN PARTICIPATION CONSIDERATIONS .......................................................... - 29 -

5. ENTITY OF CONCERN PROHIBITION ........................................................................ - 29 -

6. PROHIBITION RELATED TO MALIGN FOREIGN TALENT RECRUITMENT PROGRAMS- 30 -

B. COMPLIANCE AND RESPONSIVENESS ............................................................................ - 30 -

C. LIMITATION ON NUMBER OF SUBMISSIONS .................................................................. - 30 -

D. COST SHARING .............................................................................................................. - 31 -

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1. BASE COST SHARE REQUIREMENT .......................................................................... - 31 -

2. INCREASED COST SHARE REQUIREMENT ................................................................ - 31 -

3. REDUCED COST SHARE REQUIREMENT .................................................................. - 31 -

4. LEGAL RESPONSIBILITY .......................................................................................... - 32 -

5. COST SHARE ALLOCATION ...................................................................................... - 32 -

6. COST SHARE TYPES AND ALLOWABILITY ................................................................ - 32 -

7. COST SHARE CONTRIBUTIONS BY FFRDCS AND GOGOS ...................................... - 33 -

8. COST SHARE VERIFICATION.................................................................................... - 33 -

III. APPLICATION CONTENTS AND FORMAT ........................................................... - 35 -

A. GENERAL APPLICATION CONTENT REQUIREMENTS ................................................... - 35 -

1. MARKING OF CONFIDENTIAL INFORMATION .......................................................... - 35 -

2. EXPORT CONTROL INFORMATION ........................................................................... - 35 -

3. IMPACTED INDIAN TRIBES DOCUMENTATION ......................................................... - 36 -

B. CONCEPT PAPERS .......................................................................................................... - 38 -

1. FIRST COMPONENT: CONCEPT PAPER ................................................................... - 38 -

2. SECOND COMPONENT: SUMMARY SLIDE ................................................................ - 39 -

3. THIRD COMPONENT: TECHNO-ECONOMIC ANALYSIS ............................................ - 39 -

4. FOURTH COMPONENT: LETTER OF COMMITMENT ................................................. - 39 -

C. FULL APPLICATIONS ..................................................................................................... - 39 -

1. FIRST COMPONENT: TECHNICAL VOLUME ............................................................ - 40 -

2. SECOND COMPONENT: SF-424 .............................................................................. - 40 -

3. THIRD COMPONENT: BUDGET JUSTIFICATION WORKBOOK/SF-424A ................... - 41 -

4. FOURTH COMPONENT: SUMMARY FOR PUBLIC RELEASE ...................................... - 41 -

5. FIFTH COMPONENT: SUMMARY SLIDE ................................................................... - 41 -

6. SIXTH COMPONENT: BUSINESS ASSURANCES & DISCLOSURES FORM ................... - 41 -

7. SEVENTH COMPONENT: BIOGRAPHICAL SKETCHES (BIOSKETCH) ........................ - 42 -

8. EIGHTH COMPONENT: CURRENT, PENDING, AND PAST SUPPORT .......................... - 43 -

9. NINTH COMPONENT: TRANSPARENCY OF FOREIGN CONNECTIONS ....................... - 44 -

10. TENTH COMPONENT: IMPACTED INDIAN TRIBES DOCUMENTATION ..................... - 45 -

11. ELEVENTH COMPONENT: TECHNO-ECONOMIC ANALYSIS ..................................... - 45 -

D. REPLIES TO REVIEWER COMMENTS ............................................................................. - 45 -

IV. SUBMISSION REQUIREMENTS AND DEADLINES.............................................. - 47 -

A. UNIQUE ENTITY IDENTIFIER AND SAM REGISTRATION ............................................. - 47 -

B. USE OF DOE EXCHANGE ........................................................................................... - 47 -

C. REQUIRED DOCUMENTS CHECKLIST AND DEADLINES ................................................ - 48 -

D. COMPLIANCE ................................................................................................................. - 50 -

E. SUPER INTELLIGENCE (SI) APPLICATION USE ............................................................. - 50 -

F. INTERGOVERNMENTAL REVIEW ................................................................................... - 51 -

V. APPLICATION REVIEW INFORMATION .............................................................. - 52 -

A. RESPONSIVENESS ........................................................................................................... - 52 -

1. TECHNICAL RESPONSIVENESS REVIEW ................................................................... - 52 -

2. SUBMISSIONS SPECIFICALLY NOT OF INTEREST ...................................................... - 52 -

B. REVIEW CRITERIA ........................................................................................................ - 53 -

1. CRITERIA FOR CONCEPT PAPERS ............................................................................ - 53 -

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2. CRITERIA FOR FULL APPLICATIONS ........................................................................ - 54 -

3. CRITERIA FOR REPLIES TO REVIEWER COMMENTS ................................................ - 55 -

C. PROGRAM POLICY FACTORS ........................................................................................ - 55 -

D. REVIEW AND SELECTION PROCESS .............................................................................. - 56 -

1. CONCEPT PAPERS .................................................................................................... - 56 -

2. FULL APPLICATIONS ............................................................................................... - 56 -

3. REPLY TO REVIEWER COMMENTS ........................................................................... - 56 -

4. PRE-SELECTION CLARIFICATIONS AND “DOWN-SELECT” PROCESS ...................... - 57 -

5. SELECTION FOR AWARD NEGOTIATIONS ................................................................. - 57 -

E. ARPA-E REVIEWERS .................................................................................................... - 57 -

F. ARPA-E SUPPORT CONTRACTORS .............................................................................. - 58 -

G. RISK REVIEW ................................................................................................................. - 58 -

H. DUE DILIGENCE REVIEW FOR RESEARCH, TECHNOLOGY & ECONOMIC SECURITY . - 59 -

VI. AWARD NOTICES AND AWARD TYPES ................................................................ - 61 -

A. AWARD NOTICES ........................................................................................................... - 61 -

1. REJECTED SUBMISSIONS ......................................................................................... - 61 -

2. CONCEPT PAPER NOTIFICATIONS ........................................................................... - 61 -

3. FULL APPLICATION NOTIFICATIONS ....................................................................... - 61 -

A. SUCCESSFUL APPLICANTS ....................................................................................... - 62 -

B. POSTPONED SELECTION DETERMINATIONS ............................................................ - 62 -

C. UNSUCCESSFUL APPLICANTS ................................................................................... - 62 -

B. PRE-AWARD COSTS ....................................................................................................... - 62 -

C. RENEWAL AWARDS ....................................................................................................... - 63 -

D. FUNDING AGREEMENT TYPES....................................................................................... - 63 -

1. COOPERATIVE AGREEMENTS .................................................................................. - 63 -

2. FUNDING AGREEMENTS WITH FFRDCS/DOE LABS, GOGOS, AND FEDERAL

INSTRUMENTALITIES ......................................................................................................... - 63 -

3. OTHER TRANSACTIONS AUTHORITY ........................................................................ - 64 -

VII. POST-AWARD REQUIREMENTS AND ADMINISTRATION .............................. - 65 -

A. NATIONAL POLICY REQUIREMENTS ............................................................................. - 65 -

1. NATIONAL POLICY ASSURANCES ............................................................................. - 65 -

2. ENVIRONMENTAL IMPACT QUESTIONNAIRE ........................................................... - 65 -

B. ADMINISTRATIVE REQUIREMENTS ............................................................................... - 66 -

1. COST SHARE PAYMENTS.......................................................................................... - 66 -

2. INTELLECTUAL PROPERTY MANAGEMENT PLAN AND DATA MANAGEMENT AND

SHARING PLAN .................................................................................................................. - 66 -

3. U.S. COMPETITIVENESS .......................................................................................... - 67 -

4. NONDISCLOSURE AND CONFIDENTIALITY AGREEMENTS REPRESENTATIONS ......... - 68 -

5. INTERIM CONFLICT OF INTEREST POLICY FOR FINANCIAL ASSISTANCE ................ - 69 -

6. COMPLIANCE AUDIT REQUIREMENT ....................................................................... - 69 -

7. RESEARCH SECURITY TRAINING REQUIREMENT .................................................... - 69 -

8. FOREIGN COLLABORATION CONSIDERATIONS ........................................................ - 70 -

C. REPORTING .................................................................................................................... - 70 -

1. FRAUD, WASTE, AND ABUSE ................................................................................... - 71 -

2. COMMERCIALIZATION PLAN AND SOFTWARE REPORTING ...................................... - 71 -

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VIII. OTHER INFORMATION ........................................................................................... - 72 -

A. TITLE TO SUBJECT INVENTIONS ................................................................................... - 72 -

B. GOVERNMENT RIGHTS IN SUBJECT INVENTIONS ......................................................... - 73 -

1. GOVERNMENT USE LICENSE ................................................................................... - 73 -

2. MARCH-IN RIGHTS.................................................................................................. - 73 -

C. RIGHTS IN TECHNICAL DATA ....................................................................................... - 73 -

D. PROTECTED PERSONALLY IDENTIFIABLE INFORMATION ........................................... - 74 -

E. PRESIDENTIAL MEMORANDUM ON SIMPLIFYING FUNDING OF ENERGY

INFRASTRUCTURE AND CRITICAL MINERAL AND MATERIAL PROJECTS .......................... - 75 -

IX. GLOSSARY..................................................................................................................... - 76 -

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BASIC INFORMATION

KEY DATES:

Notice of Funding Opportunity (NOFO) Issue Date: October 21, 2026

Deadline for Concept Paper Questions to ARPA-E-

CO@hq.doe.gov:

5 PM ET, November 10, 2026

Submission Deadline for Concept Papers: 9:30 AM ET, November 20, 2026

Anticipated Date for Encourage/Discourage Notifications: 5 PM ET, January 5, 2027

Deadline for Full Application Questions to ARPA-E-

CO@hq.doe.gov:

5 PM ET, TBD

Submission Deadline for Full Applications: 9:30 AM ET, TBD

Expected Reviewer Comment Release Date: 5 PM ET, TBD

Submission Deadline for Replies to Reviewer Comments: 5 PM ET, TBD

Anticipated Timeframe for Selection Notifications: April 2027

Anticipated Timeframe for Award: July 2027

Anticipated Period of Performance: July 2027–July 2030

BASIC INFORMATION:

Total Amount to

Be Awarded

Approximately $45 million, subject to the availability of appropriated funds to be shared between NOFOs DE-FOA-0003630 and DE-FOA-0003631.

Anticipated

Number and Value of Awards

ARPA-E anticipates making approximately 9–12 awards between NOFOs

DE-FOA-0003630 and DE-FOA-0003631. ARPA-E may issue one, multiple, or no awards under this NOFO. The Federal share of awards under this NOFO may vary between $3 million and $5 million.

Agency Contact

Information

• Questions and answers (Q&As) about ARPA-E and this specific

NOFO: http://arpa-e.energy.gov/faq.

• Send other questions about the NOFO to ARPA-E-CO@hq.doe.gov.

• Send questions about use of DOE eXCHANGE to

ExchangeHelp@hq.doe.gov.

Upon the issuance of a NOFO, only the Grants Officer via ARPA-E-

CO@hq.doe.gov may communicate with applicants. This “quiet period” remains in effect until ARPA-E’s selection notification letters are distributed. Emails sent to other email addresses will be disregarded.

The Unlocking New Levels of Output and Capacity for Key Subsurface Resources

(UNLOCK) program seeks to deliver a step-change improvement in energy and critical resource extraction from the subsurface. This program will address persistent geological and technical obstacles that impede efficient recovery from diverse subsurface resources including oil, natural gas, geothermal, and mineral systems. UNLOCK will target key opportunities including improving extraction efficiency from low permeability formations, maximizing resource recovery, and optimizing water management, while maintaining cost efficiency.

Hydraulic fracturing and horizontal drilling ushered in the shale revolution, transforming once uneconomic subsurface formations into productive reservoirs that now supply the majority of oil and gas production in the United States (U.S.). Despite these advances, recovery mailto:ARPA-E-CO@hq.doe.gov mailto:ARPA-E-CO@hq.doe.gov mailto:ARPA-E-CO@hq.doe.gov mailto:ARPA-E-CO@hq.doe.gov http://arpa-e.energy.gov/faq mailto:ARPA-E-CO@hq.doe.gov mailto:ExchangeHelp@hq.doe.gov mailto:ARPA-E-CO@hq.doe.gov mailto:ARPA-E-CO@hq.doe.gov

- 7 -efficiency remains low, often below 20%, leaving most of the hydrocarbons trapped underground.1,2,3 Current stimulation methods use significant amounts of water, generate large volumes of produced water, and are unable to achieve precise control over fracture network geometry and connectivity. Furthermore, enhanced oil recovery (EOR) methods, effective in conventional reservoirs, have yielded limited success in ultra-low permeability formations due to poor reservoir contact.

Similar problems constrain other subsurface resources, including geothermal energy, in-situ mineral extraction, coalbed methane, and emerging fields such as geologic hydrogen. In these resources, technical hurdles including restricted reservoir contact, complex rock-fluid interactions, and sensing limitations continue to impede sustained recovery. Complex demands for water usage and produced-water management also compound these issues. The shared technical barriers across these sectors present an opportunity for developing cross-cutting technologies to accelerate progress.

The UNLOCK program aims to address these challenges by supporting efforts to develop and field-validate integrated stimulation and enhanced recovery approaches that can deliver transformative (not incremental) performance improvement in subsurface resource recovery.

The program’s goal is to double the per-well recovery efficiency of energy and critical resources from low-permeability formations, while maintaining or reducing both per-unit cost and wastewater volume relative to state-of-the-art methods. Achieving this goal requires innovative approaches to stimulation and enhanced recovery processes supported by rigorous laboratory experiments, numerical modeling, and downhole monitoring. After successful laboratory proof of concept, technologies will undergo field validation to ensure a practical path to real-world deployment. Success will not only revolutionize subsurface resource recovery but also contribute to ARPA-E’s goals of reducing foreign energy imports and enhancing the nation’s energy infrastructure resilience.

1 U.S. Energy Information Administration, “Technically Recoverable Shale Oil and Shale

Gas Resources: Northern South America” (September 2015):

https://www.eia.gov/analysis/studies/worldshalegas/pdf/overview.pdf.

2 M. R. Fassihi and A. R. Kovscek, “Low-Energy Processes for Unconventional Oil

Recovery,” Society of Petroleum Engineers (2017): https://doi.org/10.2118/9781613994757.

3 U.S. Department of Energy - National Energy Technology Laboratory, “Unconventional Resources,” (2019): https://netl.doe.gov/sites/default/files/2019-04/Program-

130.pdf.

https://www.eia.gov/analysis/studies/worldshalegas/pdf/overview.pdf https://doi.org/10.2118/9781613994757 https://netl.doe.gov/sites/default/files/2019-04/Program-130.pdf https://netl.doe.gov/sites/default/files/2019-04/Program-130.pdf

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I. FUNDING OPPORTUNITY DESCRIPTION

A. AGENCY OVERVIEW

The Advanced Research Projects Agency—Energy (ARPA-E), an organization within the

Department of Energy (DOE), is chartered by Congress in the America COMPETES Act of 2007

(P.L. 110-69), as amended by the America COMPETES Reauthorization Act of 2010

(P.L. 111-358), as further amended by the Energy Act of 2020 (P.L. 116-260).

ARPA-E issues this Notice of Funding Opportunity (NOFO) under its authorizing statute codified at 42 U.S.C. § 16538.4 The NOFO and any cooperative agreements or grants made under this NOFO are subject to 2 C.F.R. Part 200 as supplemented by 2 C.F.R. Part 910.

ARPA-E funds research on, and the development of, transformative science and technology solutions to address the energy and environmental missions of the Department. The agency focuses on technologies that can be meaningfully advanced with a modest investment over a defined period of time in order to catalyze the translation of scientific discovery into early-stage technology. For the latest news and information about ARPA-E, its programs and the research projects currently supported, see: http://arpa-e.energy.gov/.

ARPA-E funds transformational research. Existing energy technologies generally progress on established “learning curves” where refinements to a technology and the economies of scale that accrue as manufacturing and distribution develop drive improvements to the cost/performance metric in a gradual fashion. This continual improvement of a technology is important to its increased commercial deployment and is appropriately the focus of the private sector or the applied technology offices within DOE. In contrast, ARPA-E supports transformative research that has the potential to create fundamentally new learning curves.

ARPA-E technology projects typically start with cost/performance estimates well above the level of an incumbent technology. Given the high risk inherent in these projects, many will fail to progress, but some may succeed in generating a new learning curve with a projected cost/performance metric that is significantly better than that of the incumbent technology.

ARPA-E will provide support at the highest funding level only for submissions with significant technology risk, aggressive timetables, and careful management of the associated risks.

ARPA-E funds technology with the potential to be disruptive in the marketplace. The mere creation of a new learning curve does not ensure market penetration. Rather, the ultimate value of a technology is determined by the marketplace, and impactful technologies ultimately become disruptive—that is, they are widely adopted and displace existing technologies from the marketplace or create entirely new markets. ARPA-E understands that definitive proof of market disruption takes time, particularly for energy technologies. Therefore, ARPA-E funds the development of technologies that, if technically successful, have clear disruptive potential, e.g., by demonstrating capability for manufacturing at competitive cost and deployment at scale.

4 ARPA-E, Authorization (2026). https://arpa-e.energy.gov/about/arpa-e-at-a-glance/authorization.

http://arpa-e.energy.gov/ https://arpa-e.energy.gov/about/arpa-e-at-a-glance/authorization https://arpa-e.energy.gov/about/arpa-e-at-a-glance/authorization

- 9 -

ARPA-E funds applied research and development (R&D). The Office of Management and Budget defines “applied research” as an “original investigation undertaken in order to acquire new knowledge…directed primarily towards a specific practical aim or objective” and defines “experimental development” as “creative and systematic work, drawing on knowledge gained from research and practical experience, which is directed at producing new products or processes or improving existing products or processes.”5 Applicants interested in receiving financial assistance for basic research (defined by the Office of Management and Budget as

“experimental or theoretical work undertaken primarily to acquire new knowledge of the underlying foundations of phenomena and observable facts”)1 should contact the DOE’s Office of Science. Office of Science national scientific user facilities (http://science.energy.gov/user-facilities/) are open to all researchers, including ARPA-E applicants and awardees. These facilities provide advanced tools of modern science including accelerators, colliders, supercomputers, light sources, and neutron sources, as well as facilities for studying the nanoworld, the environment, and the atmosphere. Projects focused on early-stage R&D for the improvement of technology along defined roadmaps may be more appropriate for support through the DOE applied energy offices, including: the Office of Critical Minerals and Energy

Innovation (CMEI) , the Hydrocarbon and Geothermal Energy Office, the Office of Nuclear

Energy, and the Office of Electricity.

ARPA-E encourages submissions stemming from ideas that still require proof-of-concept

R&D efforts as well as those for which some proof-of-concept demonstration already exists.

Submissions can propose a project with the end deliverable being an extremely creative, but partial solution.

B. PROGRAM OVERVIEW

1. BACKGROUND AND MOTIVATION

Subsurface resources, including oil, gas, geothermal, and mineral systems, underpin modern energy security, industrial productivity, and economic competitiveness. However, substantial technical hurdles related to the extraction of these resources limit their full potential, especially within geologically complex formations characterized by low matrix permeability and inefficient resource mobility.

Oil and Gas

The combination of horizontal drilling and hydraulic fracturing (Figure 1) has revolutionized U.S. energy supply and made unconventional oil and gas fundamental to U.S.

energy security. These methods now account for the production of over 64% of domestic oil and

5 Office of Management & Budget, OMB Circular A-11 (2025).

https://www.whitehouse.gov/wp-content/uploads/2018/06/a11_web_toc.pdf http://science.energy.gov/ http://science.energy.gov/ http://science.energy.gov/user-facilities/ http://science.energy.gov/user-facilities/ https://www.energy.gov/cmei/about-office-energy-efficiency-and-renewable-energy https://www.energy.gov/cmei/about-office-energy-efficiency-and-renewable-energy https://www.energy.gov/hgeo/hydrocarbons-and-geothermal-energy-office http://www.energy.gov/ne/office-nuclear-energy http://www.energy.gov/ne/office-nuclear-energy https://www.energy.gov/oe/office-electricity https://www.whitehouse.gov/wp-content/uploads/2018/06/a11_web_toc.pdf

- 10 -

78% of domestic natural gas from shale and tight formations.6,7 Despite the substantial production, the recovery efficiency (or recovery factor) remains strikingly low. Although the

United States boasts 1,778 trillion cubic feet of recoverable shale and tight gas and 191 billion barrels (bbl) of recoverable unconventional oil,6 over 80% of the resource remains trapped underground, and well output may decline up to 50% within the first year of operation.2,8,9,10,11

Figure 1. Generalized schematic of hydraulic fracturing for oil and gas development highlighting the water-energy nexus.12

6 Center for Sustainable Systems, University of Michigan, “Unconventional Fossil Fuels

Factsheet,” Pub. No. CSS13-19 (2024): https://css.umich.edu/sites/default/files/2024-

10/Unconventional%20Fossil%20Fuels_CSS13-19.pdf.

7 “How much shale gas is produced in the United States?” U.S. Energy Information

Administration, Last modified: September 19, 2024, https://www.eia.gov/tools/faqs/faq.php?id=907&t=8.

8 S. Hendrickson, “Why US Shale Production Declines Are Higher Than You Might

Think,” Hart Energy (June 24, 2020), https://www.hartenergy.com/exclusives/why-us-shale-production-declines-are-higher-you-might-think-188251.

9 G. Thakur, “Management: Enhanced Recovery Technologies for Unconventional Oil

Reservoirs,” Journal of Petroleum Technology 71, no. 9 (2019): 66–69, https://doi.org/10.2118/0919-0066-JPT.

10 F. I. Syed, A. K. Dahaghi, T. Muther, “Laboratory to field scale assessment for EOR applicability in tight oil reservoirs,” Petroleum Science 19, no.5 (2022): 2131–2149, https://doi.org/10.1016/j.petsci.2022.04.014.

11 U.S. Energy Information Administration, “EIA/ARI World Shale Gas and Shale Oil

Resource Assessment—Technically Recoverable Shale Gas and Shale Oil Resources: An

Assessment of 137 Shale Formations in 41 Countries Outside the United States,” (June 2013):

https://www.eia.gov/analysis/studies/worldshalegas/pdf/overview.pdf.

12 U.S. Geological Survey, “Water Quality Topics: Hydraulic Fracturing,” USGS Office of Water Quality (December 2016): https://water.usgs.gov/owq/topics/hydraulic-fracturing/.

https://css.umich.edu/sites/default/files/2024-10/Unconventional%20Fossil%20Fuels_CSS13-19.pdf https://css.umich.edu/sites/default/files/2024-10/Unconventional%20Fossil%20Fuels_CSS13-19.pdf https://www.eia.gov/tools/faqs/faq.php?id=907&t=8 https://www.hartenergy.com/exclusives/why-us-shale-production-declines-are-higher-you-might-think-188251 https://www.hartenergy.com/exclusives/why-us-shale-production-declines-are-higher-you-might-think-188251 https://doi.org/10.2118/0919-0066-JPT https://doi.org/10.1016/j.petsci.2022.04.014 https://www.eia.gov/analysis/studies/worldshalegas/pdf/overview.pdf https://water.usgs.gov/owq/topics/hydraulic-fracturing/

- 11 -

These limitations force continuous drilling of new wells to maintain production volumes, and this strategy is complicated by operational limitations. Infill drilling frequently leads to well interference, diminishing output from both new and existing wells due to overlapping stimulated rock volumes and pressure communication between boreholes.13 The depletion of prime "Tier 1" drilling locations exacerbates this problem, forcing operators to target lower-quality reservoirs or employ tighter infill spacing. Even though technological advancements such as longer laterals, increased proppant usage, and greater water volumes have been implemented to counteract these challenges, the inherently low permeability of unconventional rock, coupled with limited control over subterranean fracture formation and interaction, means that a substantial portion of the oil and gas remains unrecoverable. Overall, transformative approaches are needed to address low recovery rates, steep production decline, and concerns regarding water sourcing, wastewater management, and related risks.

Other Subsurface Resources

The fundamental challenge of extracting valuable resources from low-permeability, hard-to-access rock formations extends beyond oil and gas. Efficient extraction of other subsurface resources, such as geothermal energy, minerals and metals, and coalbed methane, also depends on creating and maintaining connective, conductive pathways for fluid or heat transport.

Addressing these shared challenges presents a significant opportunity for cross-cutting advancements that will enhance recovery efficiency across diverse subsurface systems.

2. TECHNICAL CHALLENGES

Oil and Gas

Low permeability and resource access. Shale and tight formations exhibit extremely low permeabilities, ranging from nanodarcys to microdarcys (approximately 10⁻18 to 10⁻21 m2), which prevents economic hydrocarbon flow without significant permeability enhancement or stimulation. Hydraulic fracturing remains the dominant method for achieving this enhancement and requires the injection of millions of gallons of water along with millions of pounds of proppants per well to create conductive fractures.14,15 Its effectiveness is hindered by non-uniform fractures and poor connectivity with natural fractures, reducing effective stimulated reservoir volume, sweep efficiency, and overall recovery.

13 T. M. Al-Shami, S. R. Jufar, S. Kumar, H. Abdulelah, M. B. Abdullahi, S. Al-Hajri, and B. M. Negash, “A comprehensive review of interwell interference in shale reservoirs,”

Earth-Science Reviews, 237 (2023): 104327, https://doi.org/10.1016/j.earscirev.2023.104327.

14 M. U. Shafiq, S. Alajmei, M. S. Aljawad, L. Wang, and A. Bahri, “A Comprehensive

Review of Proppant Selection in Unconventional Reservoirs,” ACS Omega, 10, no. 13 (2025):

13046–13059, https://doi.org/10.1021/acsomega.4c09936.

15 T. Halsey, G. Agrawal, J. R. Bailey, M. Balhoff, S. Borglum, K. K. Mohanty, and M.

T. Traver, “Grand Challenges for the Oil and Gas Industry for the Next Decade and Beyond,”

Journal of Petroleum Technology 75 no. 7 (2023): 52–56, http://dx.doi.org/10.2118/0723-0052-

JPT.

https://doi.org/10.1016/j.earscirev.2023.104327 https://doi.org/10.1021/acsomega.4c09936 http://dx.doi.org/10.2118/0723-0052-JPT http://dx.doi.org/10.2118/0723-0052-JPT

- 12 -

Fracture conductivity and propagation. Proppants are crucial for maintaining the conductivity of hydraulically induced fractures, creating pathways for hydrocarbon flow once injection stops. However, traditional proppants (primarily sand) often fail to reach fracture extremities due to factors such as leak-off and settling, causing early closure and diminished flow contribution. Proppant effectiveness is further impaired by crushing, embedding, and chemical and thermal degradation, which diminish fracture conductivity and, consequently, hydrocarbon flow.144 Although engineered proppants (e.g., resin-coated, ceramic) offer enhanced strength and durability, widespread adoption is limited by their higher cost compared with sand.

In addition, fracture orientation is strongly governed by the in-situ stress field, which is poorly characterized and difficult to control, leading to unpredictable fracture propagation and uneven stimulation. This challenge is further compounded during refracturing operations.

Enhanced recovery. Despite success in conventional fields, enhanced oil recovery

(EOR) methods have shown marginal success in unconventional formations due to their ultra-low permeability.9,10 Injected fluids (e.g., CO2, surfactants, solvents) are largely confined to the fracture network, with minimal access to the hydrocarbons in the unstimulated matrix. Non-uniform fracture connectivity further causes fluid channeling and inefficient displacement, while complex fluid-rock-hydrocarbon interactions add uncertainties. Together, these hurdles constrain the economic viability of EOR in shale and tight formations.

Refracturing. Refracturing existing wells offers an economic alternative to drilling new wells but faces major challenges. Success depends on accurately characterizing existing fractures and diverting fluids into unstimulated rock, rather than depleted zones, which requires advanced diversion and flow control technologies.

Inter-well interference, common in both refracturing and infill drilling, can reduce neighboring wells’ productivity. Without precise candidate selection, accurate reservoir characterization, and improved downhole control, refracturing yields will continue to be economically uncertain.Error! Bookmark not defined.16

Water management. Each shale and tight well requires 1.5 to 16 million gallons of water for hydraulic fracturing and generates 1–12 bbl of produced water (a combination of formation water and fracturing water) per barrel of oil equivalent (BOE) over its lifecycle.17,18 Although some of the produced water is reused for fracturing, the majority is still disposed of via injection

16 L. Xu, D. Wang, L. Liu, C. Wang, H. Zhu, and X. Tang, “Review of Shale Oil and Gas

Refracturing: Techniques and Field Applications,” Processes 12, no. 5 (2024): 965, https://doi.org/10.3390/pr12050965.

17 J. Nicot, R. Darvari, P. Eichhubl, B. R. Scanlon, B. A. Elliott, L. T. Bryndzia, J. F. W.

Gale, and A. Fall, “Origin of low salinity, high volume produced waters in the Wolfcamp Shale

(Permian), Delaware Basin, USA,” Applied Geochemistry 122 (2020): 104771, https://doi.org/10.1016/j.apgeochem.2020.104771.

18 U.S. Environmental Protection Agency, “Summary of Input on Oil and Gas Extraction

Wastewater Management Practices Under the Clean Water Act,” EPA-821-S19-001 (May 2020), https://www.epa.gov/sites/default/files/2020-05/documents/oil-gas-final-report-2020.pdf.

https://doi.org/10.3390/pr12050965 https://doi.org/10.1016/j.apgeochem.2020.104771 https://www.epa.gov/sites/default/files/2020-05/documents/oil-gas-final-report-2020.pdf

- 13 -wells, posing potential environmental risks. Additionally, the high salinity and complex chemistry of the produced water make surface treatment costly.

Sensing and far-field characterization. Current diagnostic tools such as microseismic and distributed fiber optic sensing offer limited resolution of fracture dimensions, connectivity, and conductivity. This limitation leads to difficulty in mapping fracture networks, characterizing unstimulated zones to estimate undrained volumes, and monitoring fluid migration in the far field. Furthermore, effectively monitoring proppant distribution and assessing fracture conductivity within the stimulated region remains an unsolved challenge. The long-term monitoring capabilities are also constrained by the durability of sensors in harsh downhole environments.

(a) (b)

(c)

Figure 2. (a) Enhanced geothermal system,19 (b) in-situ leaching,20 and (c) coalbed methane reservoir.21

19 R. Horne, A. Genter, M. McClure, W. Ellsworth, J. Norbeck, and E. Schill, “Enhanced geothermal systems for clean firm energy generation,” Nature Reviews Clean Technology 1, no.

2 (2025): 148–160, https://doi.org/10.1038/s44359-024-00019-9.

20 F. L. Pellet, “Rock Mechanics and Environmental Engineering for Energy and Geo-

Resources,” ISRM European Rock Mechanics Symposium—EUROCK 2018 (May 2018):

https://onepetro.org/ISRMEUROCK/proceedings-abstract/EUROCK18/EUROCK18/ISRM-

EUROCK-2018-008/446917.

21 Q. Huang, S. Liu, G. Wang, B. Wu, and Y. Zhang, “Coalbed methane reservoir stimulation using guar-based fracturing fluid: A review,” Journal of Natural Gas Science and

Engineering 66, no. 6 (2019): 107–125, https://doi.org/10.1016/j.jngse.2019.03.027.

https://doi.org/10.1038/s44359-024-00019-9 https://onepetro.org/ISRMEUROCK/proceedings-abstract/EUROCK18/EUROCK18/ISRM-EUROCK-2018-008/446917 https://onepetro.org/ISRMEUROCK/proceedings-abstract/EUROCK18/EUROCK18/ISRM-EUROCK-2018-008/446917 https://doi.org/10.1016/j.jngse.2019.03.027

- 14 -

Other Subsurface Resources

The challenge of mobilizing and recovering resources from low-permeability, geologically complex formations extends beyond shale and tight oil and gas reservoirs, constraining other subsurface resources, such as those depicted in Figure 2.

• Enhanced geothermal systems (EGS), particularly in hot dry rock and low-permeability basement formations, face difficulties in sustaining conductive fractures and in maintaining uniform flow across them. This difficulty leads to thermal short circuiting and suboptimal thermal recovery.22 Sand-based proppants may degrade under high temperatures and stress, causing conductivity loss. High temperatures limit sensor longevity. Monitoring fracture propagation, fluid pathways, and far-field behavior also remains challenging. Circulation losses (~230 to 4,200 gallons per megawatt-hour) raise water demand and seismic risks, while scaling clogs flow paths.23,24

• In-situ leaching operations for extracting minerals and metals face challenges in low permeability formations due to poor leaching agent (i.e., lixiviant) to rock contact, resulting in low recovery.25 Containment of injected fluids during in-situ leaching is critical for groundwater protection, but current wellbore monitoring methods (e.g., logging) are inadequate to track complex subsurface flow, geochemical interactions, and far-field fluid excursions. Further difficulties arise from post-leaching groundwater restoration and wastewater management. For example, uranium recovery can generate

50–250 gallons of wastewater per pound of uranium recovered, underscoring the need for effective water management strategies.26

• Coalbed methane production requires extensive dewatering that yields significant wastewater, presenting costly treatment and disposal challenges. The low, anisotropic permeability of coal seams often necessitates stimulation and enhanced recovery to

22 M. L. McLean, and D. N. Espinoza, “Thermal destressing: Implications for short-circuiting in enhanced geothermal systems,” Renewable Energy 202(2023): 736–755, https://doi.org/10.1016/j.renene.2022.11.102.

23 C. B. Harto, J. N. Schroeder, R. M. Horner, T. L. Patton, L. A. Durham, D. J. Murphy, and C. E. Clark, “Analysis of the 2024 Circulation Tests at Utah FORGE and the Response of

Fiber Optic Sensing Data,” Argonne National Lab/EVS-14/14 (October 2014):

https://gdr.openei.org/files/464/ANL:EVS-14:14%20(1).pdf.

24 P. Xing, K. England, J. Moore, and J. McLennan “Analysis of the 2024 Circulation

Tests at Utah FORGE and the Response of Fiber Optic Sensing Data,” Workshop on Geothermal

Reservoir Engineering, Stanford University (2025), https://pangea.stanford.edu/ERE/db/GeoConf/papers/SGW/2025/Xing2.pdf .

25 L. Sinclair, and J. Thompson, “In situ leaching of copper: Challenges and future prospects,” Hydrometallurgy 157, no. 10 (2015): 306–324, https://doi.org/10.1016/j.hydromet.2015.08.022.

26 T. J. Gallegos, A. M. Scott, V. G. Stengel, and A. P. Teeple, “A Methodology to

Assess the Historical Environmental Footprint of In-Situ Recovery (ISR) of Uranium: A

Demonstration in the Goliad Sand in the Texas Coastal Plain, USA,” Minerals 12, no. 1 (2022):

369, https://doi.org/10.3390/min12030369.

https://doi.org/10.1016/j.renene.2022.11.102 https://gdr.openei.org/files/464/ANL:EVS-14:14%20(1).pdf https://pangea.stanford.edu/ERE/db/GeoConf/papers/SGW/2025/Xing2.pdf https://doi.org/10.1016/j.hydromet.2015.08.022 https://doi.org/10.3390/min12030369

- 15 -maintain production. Overcoming hurdles in characterizing permeability, dewatering, and tracking subsurface gas fronts is crucial for optimizing production.

A critical opportunity exists to develop crosscutting, next-generation technologies that enhance stimulation and recovery efficiency, expand flow pathways, and improve water management across diverse subsurface systems.

C. PROGRAM OBJECTIVES

The Unlocking New Levels of Output and Capacity for Key Subsurface Resources

(UNLOCK) program seeks fundamentally disruptive technologies to markedly improve resource recovery from low-permeability subsurface environments. The program aims to improve upon state-of-the-art (SoA) methods by:

• Doubling the per-well recovery efficiency of energy and mineral resources from challenging formations

• Maintaining or reducing per-unit costs

• Maintaining or reducing the associated wastewater burden

Achieving this goal requires transformative approaches that integrate innovative stimulation and enhanced recovery processes with advanced sensing and comprehensive numerical and experimental modeling. If successful, this program will transform subsurface resource recovery, directly advancing ARPA-E’s statutory goals of reducing foreign energy imports and enhancing energy security and infrastructure resilience.

D. TECHNICAL CATEGORIES OF INTEREST

The UNLOCK program is interested in transformative approaches that combine novel stimulation and enhanced recovery methods, supported by integrated sensing and comprehensive modeling. ARPA-E expects proposed technologies to achieve laboratory and numerical validation against the program objectives in Section I.C., culminating in a field trial that shows sustained recovery, cost-effectiveness, and wastewater metric validation under realistic geological and operational conditions.

The UNLOCK program seeks innovative solutions to the technical barriers described in

Section I.B.2. Applicants can choose from one of two categories: Category A (Shale and Tight

Oil & Gas) and Category B (Other Low-Permeability Subsurface Resources). ARPA-E anticipates that Category A will comprise the majority of projects selected under this program.

1. TECHNOLOGIES OF INTEREST

For both categories, technologies of interest include, but are not limited to, the following:

• Waterless or low-water fracturing or stimulation technologies that could improve resource access by creating more uniform, dense, durable, and controlled fracture networks, such as:

- 16 -o Energized gas injection (e.g., supercritical CO2, nitrogen) o Chemical stimulation o Electric discharge fracturing o Pulsed plasma fracturing o High-energy laser-based stimulation o Thermal and acoustic stimulations o Self-propagating fracture networks

• Advanced recovery fluids to improve resource mobility and flow conformance, including biologically derived, nanomaterial-enhanced, adaptive, and catalytic reagents, such as:

o Supercritical, nanoparticle-enhanced, or microbe-assisted recovery fluids that can enhance permeability, alter interfacial properties, and selectively mobilize trapped resources o Adaptive, responsive, or phase-changing fluids, such as temperature or pressure-activated gels

• Engineered proppants that can improve fracture conductivity, reservoir connectivity, and production performance, such as:

o Shape-adaptive (expanding or deformable) o Reactive o Catalytic o In-situ generated o Multifunctional (e.g., sensing, scale-inhibiting) o High-temperature stable

• Advanced diagnostics and modeling for real-time subsurface monitoring, such as:

o Distributed chemical sensing capable of tracking fluid composition variations o Quantum sensors with high sensitivity to reservoir changes o Swarm-based sensors that could enable detailed spatial mapping of fracture networks and fluid flow o Micro-sensors o Quantum computing o Super intelligence o Integrated experimental validation

2. SUBMISSION AND TEAM LOGISTICS

Both Category A and B submissions must be composed of two phases, each lasting approximately 18 months. Phase 1 (Laboratory Validation) includes controlled laboratory experiments using test-site-specific samples, and Phase 2 (Field Testing) will serve as an opportunity to test the performance of the developed technology at realistic well-scale conditions. The criteria for success under this program are ultimately defined by performance at the field test site. However, laboratory and numerical models must first indicate that the technology's inherent capabilities and predicted behaviors will translate into the successful attainment of the metrics at the field test site. These phases enable the program to focus on field-testing only the technologies that show clear evidence of the ability to meet program targets.

- 17 -

Submissions must propose project plans and budgets for both Phase 1 and Phase 2.

Funding for both phases will be obligated at the start of the Period of Performance, but advancement from Phase 1 to Phase 2 is at ARPA-E’s sole discretion. This decision will depend on whether a project team’s laboratory experiments validate the technology’s ability to meet the targets in Sections I.C and I.E and on the quality of deliverables. The transition from Phase 1 to

Phase 2 represents a portfolio-wide down-select, so advancement is not guaranteed even if all milestones from Phase 1 are met.

For both categories, submissions must address the following requirements:

• Integration of Stimulation and Enhanced Recovery: Combine a…