The U.S. Geological Survey recently released assessments detailing the estimated volumes of undiscovered, discovered and technically recoverable oil and gas resources in several basins across Wyoming, southern Montana and parts of western South Dakota and Nebraska.
The overall picture looks promising. The Lewis Shale and Powder River Basin remain the most promising in terms of future development potential. The Upper Paleozoic formations are largely mature, with limited remaining undiscovered resources. Nebraska and western South Dakota contain formations that currently contribute modestly to U.S. potential reserves but might become more significant with new technology. Overall, the region contains billions of barrels in cumulative oil potential and dozens of trillion cubic feet of natural gas, much of it unconventional (shale/tight oil).
What applies to basins in the United States applies to the world. When reviewing the results of the reports, it is important to keep in mind that new technologies are making it possible to boost recoverable reserves. The new technologies are applicable to the areas covered in the USGS report, and also, significantly, to oil and gas resources throughout the world.
USGS March 2025 Report: Upper Paleozoic Reservoirs (Wyoming and Southern Montana)
Region: Wind River, Bighorn and Powder River Basins (Wyoming and southern Montana)
Estimate (mean):
Oil: 47 million barrels
Natural gas: 876 billion cubic feet
These formations have already produced about 4 billion barrels of oil since the 1920s.
Key insight: Most recoverable resources in these older reservoirs have likely already been discovered or extracted.
USGS January 2024 Report: Lewis Shale (Wyoming and Colorado)
Region: Southwestern Wyoming and Northwestern Colorado
Formation: Lewis Shale (Late Cretaceous)
Estimate (mean):
Oil: 294 million barrels
Natural gas: 11 trillion cubic feet
Significance: Identified as a major untapped resource for future shale development due to advances in horizontal drilling and frac’ing.
Powder River Basin (Wyoming and Montana): Historical Assessment (2006)
Region: Northeastern Wyoming and Southeastern Montana
Estimate (mean):
Oil: 639 million barrels
Natural gas: 16.6 trillion cubic feet
Natural gas liquids: 131 million barrels
Note: These figures are from a 2006 assessment, but the basin remains a core area for unconventional drilling (for example, in the Turner, Parkman and Niobrara formations).
Nebraska and Western South Dakota:Williston and Denver Basins (Ongoing Studies)
Region: Nebraska panhandle, western South Dakota and bordering areas in Wyoming and Montana
While not as oil-rich as neighboring states, these areas are included in broader assessments tied to the Williston Basin and southern extensions of the Denver and Powder River Basins.
Key formations assessed:
Niobrara Formation
Codell Sandstone
Minnelusa Formation (South Dakota/Wyoming)
Estimates: USGS has ongoing assessments for these zones, with previous estimates in the tens to hundreds of millions of barrels of oil and multiple tcf of gas, depending on formation and basin extent.
New Technologies
Recent technological advancements in oil and gas exploration, drilling and completion have made more reserves technically recoverable by enhancing efficiency, reducing costs and improving recovery rates. Key developments include:
Advanced Visualization Techniques
Reservoir characterization: Advanced machine learning techniques can be applied to large, diverse data sets which include petrophysics, well logs, core analyses, diagenetic alteration studies and more for a better understanding of the reservoir and better design of completions and stimulations. AspenTech is one company that has developed visualization tools.SLB’s OFM software also provides visualization for decision-making.
3-D seismic imaging: New capabilities to conduct “smart ingestion” of seismic data and to reprocess them can produce detailed subsurface images. It is vital also in derisking drilling and completion designs.
Refracturing: Successful refracs have occurred in shale plays developed in the early years of exploration and development, when less effective frac design, inadequate proppant and frac fluids resulted in formation damage or poor results. BKV is one company that has developed what they refer to as “hybrid” refracs in the Barnett Shale with great success.
Drilling Technologies
Extended reach drilling: ERD allows for drilling longer horizontal sections, accessing reserves that were previously unreachable. By combining ERD with advanced stimulation technologies that take advantage of downhole fiber optics and real-time data, operators can optimize fluid interaction with rock formations, leading to sustained production rates along the wellbore. One company that has specialized in ERD is HXR Drilling Services, which combines the drilling programs with geomechanics and geopressured modeling to assure borehole integrity.
Automation and smart technologies: The integration of robotics, sensors and AI-powered systems enables real-time monitoring and response during drilling operations. These technologies enhance efficiency, reduce operational costs and improve safety in high-pressure environments. With its RoboLogger, diversified well logging can collect and store up to 350 samples at two minutes per sample.
Sensor Technologies and Real-Time Monitoring
Downhole sensors: Advanced sensors placed within wells provide continuous data on pressure, temperature, and flow rates. This real-time information allows for immediate adjustments to optimize production and prevent issues such as equipment failure or reservoir damage. Sensors can also monitor emissions and detect strain events for early detection and intervention in the case of leaks. Companies such as HighPeak Energy are using microseismic monitoring to better map induced fractures and also manage produced water disposal.
AI-driven data analytics: Artificial intelligence algorithms analyze vast amounts of data from drilling operations to predict potential problems and optimize drilling parameters. Companies like BP and Devon Energy have reported increased drilling efficiency and improved well productivity through AI integration. Companies such as Petrabytes have partnered with data services companies such as Amazon Web Services to develop AI-based smart data ingestion, followed by apps for decision-making.
Completion Techniques
Advances in multistage hydraulic fracturing: The ability to conduct real-time diagnostics of fracture propagation and also to improve the performance of ball-activated systems (frac sleeves) has allowed more control in longer, more complex laterals.
Plug-and-perf systems: Widely used in horizontal wells, this method allows for precise targeting of specific reservoir sections, optimizing the fracturing process and improving overall well performance.
Drilling Fluids
Advanced drilling muds: The development of environmentally-friendly drilling fluids with optimal viscosity and thermal stability has improved wellbore stability and reduced environmental impact. These fluids enhance drilling efficiency and minimize issues such as formation damage and equipment wear. Green additives can include carboxymethyl cellulose, pistachio shell powder and polyanionic cellulose. The largest providers are Halliburton, SLB, Newpark, CES, and Weatherford.
Co-Production of Geothermal Energy
Geothermal energy extraction from oil wells: Utilizing the thermal energy from produced fluids in oil and gas operations, companies can generate electricity on-site. This co-production reduces operational costs, decreases greenhouse gas emissions, and provides a renewable energy source. Projects like the Swan Hills Geothermal Project in Alberta, Canada, exemplify the successful integration of geothermal energy production with existing oil and gas infrastructure.
Conclusion
Opportunities to revisit legacy fields and drilled horizons previously considered uneconomic, or where reserves were considered unrecoverable exist throughout the world. As the recent USGS studies of a section of the United States suggest, the best opportunities exist where fresh sets of eyes find the best match of resources and new technologies. With that in mind, don’t miss URTeC 2025 and the New Technology Showcase.