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Unlocking the Tight Oil Reservoirs of the Powder River Basin, Wyoming
Project Number
DE-FE0031779
Last Reviewed Dated
Goal

The goal of this field-based research project is to establish a tight oil field laboratory in the Powder River Basin (PRB). The field laboratory will be used to characterize and overcome the technical challenges of developing two large, emerging unconventional/shale oil formations, the Mowry Shale, and the Belle Fourche Shale, with the challenging tight sands of the Frontier and Niobrara formations serving as additional objectives. 

Performer(s)

University of Wyoming — Laramie, WY 82071

Collaborators

Oxy USA, Inc — Houston, TX 
Advanced Resources International — Arlington, VA
Southern Illinois University — Carbondale, IL
NSI Fracturing, LLC — Tulsa, OK
Goolsby, Finley & Associates, LLC — Casper, WY

Background
Nitro drill pad during drilling operations.
Nitro drill pad during drilling operations

The PRB is an oil-rich basin in northeast Wyoming. While still in the delineation to early stages of development, the PRB is experiencing double-digit production growth with a forecasted production of 136,000 barrels/day. The PRB is unique in both the number of proven horizontal targets (at least 14), the thickness of the pay column (5,000 ft), and the variety of overlapping producing reservoirs. Reservoir types vary from heterogeneous sandstones with near-conventional trapping and reservoir properties to true unconventional resource plays including source rocks/targets. The PRB is emerging as a new, active industry target for tight oil development. The bulk of the recent oil wells have been drilled into the tight and non-tight sandstone formations, such as the Parkman and Turner. However, attention is also being paid to the two deeper shale oil reservoirs, the Mowry Shale and the overlying Belle Fourche Shale/Third Frontier Formation, and the extensive Frontier tight sand. The Mowry and Belle Fourche formations are estimated to hold most of the unconventional oil resource in the Basin and serve as the source rocks for the overlying tight oil sandstone reservoirs in the PRB.
The wells testing production from the Belle Fourche are highly variable, and there are few core samples available to explain the reasons for this variability. The Mowry and the Belle Fourche have high bentonite clay content, creating geomechanical issues for completion and stimulation as well as variable oil and water saturations. The porosity and permeability distribution for the tight sandstone of the Frontier formation appears to be strongly controlled by an environment of deposition and diagenetic effects, resulting in the need for improved completion and stimulation practices that can mitigate the impact of permeability and porosity degradation.
The goal of this project is to improve oil and gas recovery from Powder River horizontal wells through an improved understanding of the geological and geomechanical systems within the basin and use this understanding to engineer improved well completion and stimulation protocols to increase hydrocarbon recovery from unconventional plays. 

Impact

Optimized fracture designs, implementation of new well completion technologies, and improved field development methodologies will be developed for the PRB that will ultimately result in fit-for-purpose well completion and stimulation programs within the PRB. This will accelerate development and improve tight oil recovery, thus contributing to U.S. oil production and energy security.

Accomplishments (most recent listed first)
  • Conducted project review in early April with all team members at Oxy’s Denver offices.  Learnings from the Mowry core description were shared.
  • Slabbed and described 191 ft of core  (35 ft Belle Fourche Shale, 135 ft Mowry Shale, 18 ft Shell Creek Shale, and 3 ft Muddy Sandstone).
  • Initiated laboratory investigation of Mowry core at Southern Illinois University and University of Tulsa (NSI Fracturing Lab).
  • Completed first of three phases of establishing a Field Laboratory in the southern Powder River Basin with the drilling, logging, and coring of the vertical Pilot Hole.  
Current Status

The geological model has been updated with new data from the Pilot Hole and will be expanding outward to cover the wider southern Powder River Basin.  The Project is working with Oxy to plan drilling and instrumentation to be done on the upcoming horizontal wells, which are planned for late 2022 and early 2023.. The team has discovered that more detailed information is required for the  PRB geology and well completion database to be used to conduct meaningful multivariate analysis and machine learning activities.  In addition, the project continues working to fine tune well landing zones in order to determine which well parameters are critical to well productivity and can be optimized to improve a well. 

Project Start
Project End
DOE Contribution

$7,833,908

Performer Contribution

$7,064,850

Contact Information

NETL – Richard C. Baker (Richard.Baker@netl.doe.gov)

University of Wyoming – Eric Robertson (eric.robertson@uwyo.edu)

Additional Information
Figure 1.  A view of the core being laid out in early January at the Nitro drill pad during core retrieval.
Figure 1.  A view of the core being laid out in early January at the Nitro drill pad during core retrieval.
Figure 2.  A view of the Mowry shale core inside a liner just after retrieval from the well and before wrapping/packaging for transport to the laboratory.
Figure 2.  A view of the Mowry shale core inside a liner just after retrieval from the well and before wrapping/packaging for transport to the laboratory.