Contact Information

  • John Dewey
    (713) 702-8655


Geological Advisor & Explorationist

Identify New Resources | Deliver New Assets

Geotechnically strong explorationist who focuses on identifying key factors to find and delineate new resources, test prospects, and resolve drilling and production questions. Combines geoscience and operational expertise to implement drilling programs in unconventional reservoirs and bring insight to production results. Collaborative team member and advisor dedicated to sharing experience and mentoring new talent.

Exploration & Development Geology | Unconventional Reservoirs | Stratigraphic Interpretation | Source Rock Characterization | Petroleum Systems Analysis | Horizontal Well Planning | Operations Geology







Affirmed Resources, Houston, TX
Geologist, Exploration Manager Dec. 2019- Nov. 2020

Private equity-funded start-up. Responsible for all geologic evaluations in efforts to acquire properties for exploration & development programs.
• Eastern Shelf
- Mapped Strawn sands in Tom Green, Fisher, Scurry & Stonewall counties, Texas (structure, gross & net sand, porosity, saturations); identified 54,000-acre exploration fairway; company began program of optioning acreage for leasing.
- Evaluated two acquisition opportunities.
• Delaware Basin
- Mapped Wolfcamp in Loving, Reeves & Ward counties, Texas.
- Conducted horizontal well landing analysis in conjunction with production analysis in pursuit of potential drill-to-earn or complete-to-earn opportunities on acreage of three different companies.

J. A. Dewey Geological Consulting, Spring, TX
Consulting Geologist 2019

Worked with client’s team to generate prospects and evaluate A&D opportunities on a contractual basis.
• Northern DJ Basin Evaluation (WY & NE)
- Mapped Codell & Niobrara in Laramie, Goshen, & Platte counties (structure, reservoir parameters, saturations, shows & tests, thermal maturity).
- Identified prospective 111,000-acre fairway for acreage acquisition and exploration test. Recommendation resulted in acquisition of 10,000 gross (9200 net) acres.
- Evaluated and made recommendations on four acquisition opportunities. Presented findings and recommendations to client’s Board of Directors.

Project Geological Advisor, US Onshore Exploration 2016 to 2018

Built regional maps and delineated new unconventional plays in the Permian Basin. Mentored less-experienced staff in mapping, prospect generation, and operations.

• Central Basin Platform Exploration: Mapped San Andres Fm. in 6 counties in New Mexico and Texas in effort to identify unconventional tight carbonate reservoir potential. Established regional stratigraphy used to modify original prospect maps. Worked with geophysicist to tie Midland Basin stratigraphy to Central Basin Platform and Northern Shelf, preliminary to extending prospecting efforts.

• Basin Valuation—Delaware Basin: Participated in larger regional study of geology, production, and commercial potential of Pennsylvanian through Brushy Canyon section in Delaware Basin, increasing understanding of relative value of stacked potential of acreage across basin. Contributions included:
- Constructed regional maps (reservoir properties, pressure, and GOR) of 6 unconventional reservoirs in Avalon Shale and 1st & 2nd Bone Spring Sands across 8 counties in Texas and New Mexico.
- Worked with reservoir engineers to identify horizontal well performance drivers (reservoir, fluid characteristics, etc.). Mapped fairways delineating production potential differences.

• Additional Work: Constructed regional source rock maturity maps for Bone Spring, Wolfcamp & Woodford intervals, helping assess hydrocarbon productivity across Delaware Basin. Participated in 5-6 A&D evaluations.

Geology & Geophysics Manager, Greater Permian Exploration 2014 to 2016

Led team of 6 geoscientists in exploration efforts in Permian Basin of West Texas. Responsible for quality of geotechnical evaluations and for staff career development. Participated in management reviews of all US Onshore Exploration prospects. Contributed to development of Onshore Exploration strategy.

• Led multi-disciplinary effort (geology, geophysics, petrophysics, reservoir engineering) to conduct in-depth, basin-wide study of 12 unconventional reservoirs in the Midland Basin. Results provided tools to high-grade areas of maximum interest and to rapidly evaluate A&D opportunities. Efforts resulted in template for conducting focused, short-cycle evaluation of basins going forward.

• Led evaluation of 2nd Bone Spring sand in the Texas portion of the Delaware Basin, resulting in APC’s first well in the target and the identification of 663 MMBO gross reserves. Play was subsequently transferred to Anadarko’s Delaware Basin Development team.

• Led reconnaissance study of unconventional reservoirs of the Eastern Shelf of the Permian Basin. Concluded that reserve potential did not meet APC criteria and subsequently dropped the area as a focus.

• Leadership Training - Participated in year-long series of instructor-led training and individual coaching sessions focused on developing leadership skills, personnel development, etc.

Senior Staff Geologist, US Onshore Exploration (Upper Gulf Coast) 2013 to 2014

Generated prospects in northern Louisiana and southern Arkansas. Made recommendations for play entry, acreage acquisition, and A&D activity.

• Lower Cotton Valley Sands: Mapped sands in N. Louisiana, establishing working geological model for looking at lower Cotton Valley and Grey Sands. Recommended acquiring producing field and acreage to pursue play.

• Brown Dense: Mapped Lower Smackover Brown Dense play in N. Louisiana and S. Arkansas for horizontal unconventional potential. Utilized available well data to evaluate reservoir quality, source rock potential, thermal maturity and pressure. Recommended that APC not pursue play.

Staff Geologist & Senior Staff Geologist, Delaware Basin Operations 2007 to 2013

Served as development geologist on the Delaware Basin asset team. Created exploration prospects over APC acreage.

• Avalon Shale: Mapped upper and lower Avalon shales in Loving and Reeves Cos., TX. Initiated APC’s Avalon horizontal well program.
- Planned and executed initial horizontal wells to test 4 exploration pilot areas and 8-10 additional follow-up test wells, resulting in delineation of ~200K acres of upper Avalon resource. Picked horizontal targets. Planned data acquisition, including logging and coring programs.
- Contributed to completion plans and provided geologic input for microseismic and tracer studies.

• Wolfcamp: Mapped and developed prospects for Wolfcamp horizontal wells. Mentored staff subsequently assigned to further Wolfcamp exploration, leading to initiation of APC’s Wolfcamp program.

• Haley Field (Penn.): Mapped Strawn, Atoka & Morrow targets in the Haley Field in Loving Co., TX. Provided drilling locations and conducted geologic operations for multi-rig, vertical drilling program, including wireline logging, cuttings evaluation, pipe calls, etc.

Senior Geologist, Unconventional Reservoirs Group 2002 to 2007

Tasked with exploring for and delineating unconventional reservoirs, primarily in SW Wyoming. Worked with regulatory groups to provide geological input in support of National Environmental Protection Act (NEPA) issues.

• Atlantic Rim CBM: Delineated coalbed methane potential in the eastern Washakie Basin. Planned and tested 5 pilot areas across ~250K acres. Provided geological support for drilling including data collection and analysis (logging, coring, desorption analysis, etc.). Worked with APC regulatory group and BLM on Environmental Assessments for drilling programs. Provided long-term development plans in support of proposed Atlantic Rim EIS.

• Green River Shale Gas: Mapped Green River Shale and drilled well to core and test for shale gas potential. Worked with BLM Reservoir Management Group to address and resolve ongoing unitization issues.


Exploration Geologist, Basin Studies Group

Conducted basin reconnaissance studies of basins in S. America, N. & E. Africa, Madagascar, Mediterranean, and offshore Brunei. Incorporated commercially available reports and oil geochemistry databases.

Special Projects Coordinator, Worldwide Business Development

Monitored commercial and governmental conditions in countries in S. America and W. Africa, determining suitability for new country entry. Provided geological support for international business development efforts.

Development Geologist, North America Exploitation - SW Kansas & W. Texas

Assigned to development of APC acreage in various fields. Worked on Ketchum Mountain Field (Irion Co., TX) team that proposed waterflood.


Exploration & Development Geology | Unconventional Reservoirs | Stratigraphic Interpretation | Source Rock Characterization | Petroleum Systems Analysis | Horizontal Well Planning | Operations Geology


Master of Science (MS), Geology, Brigham Young University, Provo, UT
Bachelor of Science (BS), Geology, Brigham Young University, Provo, UT