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Deep Reservoir Studies
Project Number

This project aims to gain better information on reservoirs at 15,000 ft and greater so to enhance our understanding of future drilling targets and to aid in future improvements to technology for deep gas exploration and production.


U.S. Geological Survey

Denver, Colorado 80225


In 1997, the U.S. Geological Survey published Bulletin 2146, comprising 12 chapters dealing with geologic, geochemical, and assessment issues related to deep gas resources (Dyman and others, 1997). This project constitutes a continuation of that work to inventory and rank undiscovered, continuous-type natural gas plays at depths of 15,000 ft. and greater in the U.S. Predictive models will be developed to assist in evaluating deep reservoir rocks and potential gas generation will be investigated for these reservoirs. Deep Gulf of Mexico reservoirs such as the deep Norphlet and Frio formations will be reevaluated as part of this DOE/USGS co-funded study. Information from the USGS "World Petroleum Assessment" will also be integrated in to the results of the U.S. study. Impediments to drilling and directions for future studies of deep sedimentary basins will be included in the final report, to assist in the assessment of future deep hydrocarbon exploration and development potential.


This completed project has served as an important source of information to both industry and government organizations concerned with developing appropriate strategies for recovering natural gas from reservoirs within deep sedimentary basins in the U.S.. The final report has been a sought after source of information from DOE/NETL for many years following its completion. This particular study has served as important reference in the planning and implementation of the DOE Deep Trek Program, advanced deep drilling.

Accomplishments (most recent listed first)
  • Assessed the areal extent of drilling and the distribution of deep basins in the U.S., and provided an update of deep drilling during the 1990’s. Also, the distribution of deep sedimentary basins and the potential for deep gas in the Former Soviet Union was summarized.
  • Examined and compared six different published gas-generation kinetic models with respect to their predictions of timing and quantities of deep gas generation.
  • Conducted hydrous-pyrolysis experiments on immature source rocks to assess gas:oil ratios
  • (GOR) and the affects of kerogen type and thermal maturity during petroleum generation.
  • Developed a probabilistic method for subdividing gas resources into depth slices. The method was used to assess deep natural gas across a range of depth intervals, and estimating the amount of gas in each interval.
  • Analyzed the relative uncertainty of estimates of deep gas in more than 60 plays in the Western Gulf and Louisiana-Mississippi Salt Basin provinces
  • Evaluated the role of water on deep, high-rank spent kerogen, and the subsequent generation of methane-rich hydrocarbon gas.
Current Status

The project has been completed and the final report, Geologic Studies of Deep Natural Gas Resources has been received.

Project Start
Project End
DOE Contribution


Performer Contribution


Contact Information

USGS - Thaddeus S. Dyman (303-236-5730 or
NETL - William Gwilliam (304-285-4401 or