The U.S. Geological Survey (USGS) estimates that the Powder River Basin (PRB) contains approximately 1 billion BOE of remaining recoverable oil and 15 TCF (2.5 billion BOE) of remaining recoverable natural gas. Forty percent of the liquid hydrocarbons are believed to be contained in two unconventional shales – the Mowry and the Niobrara – while 80-90% of the gas is believed to be methane trapped in coal (CBM).
Recent liquids-rich discoveries by several PRB operators have heightened exploration interest in this basin, especially in the Mowry and Niobrara shale intervals, both of which were ignored historically as primary reservoir targets. When discoveries have been made in these shales, geoscientists have noted a correlation between both field locations and well productivity, and the proximity to lineaments and regional fault and associated fracture networks. However, these fracture-control systems are not especially well understood across the basin.
Moreover, the Niobrara is not within the liquid-generation window across all of the Powder River Basin. Liquids content is believed to increase to the northwest, where the basin deepens and the Niobrara plunges below 8,000 feet. However, well control is sparse in this area, and seismic data is limited. There is a real need, therefore, for additional data and insight to help geoscientists to better understand the relative liquids’ content of the Niobrara on an areal basis so they can target their drilling programs at the most economically advantaged portions of the play.
NEOS is currently talking to several PRB operators about launching a basin-scale regional reconnaissance survey over approximately 2,000 square miles of the basin. While a similarly sized 3-D seismic program might cost upwards of $100 million and take several years from the start of permitting to the receipt of processed and interpreted images, NEOS is able to image this same area at a fraction of the cost and deliver the results within a year. The imaging objectives being discussed with potential underwriters include:
- Defining deep basement architecture, including the impacts regional tectonic, structural, and thermal forces have had on deposition, maturation, and relative reservoir productivity within the Mowry and Niobrara intervals;
- Identifying lineaments, structural features, and regional fault and fracture networks, including their impact on the relative productivity and exploration potential of target reservoir horizons;
- Documenting direct and indirect indicators of liquid hydrocarbons on the surface and within the near-surface, as possible predictors of the relative liquid-generation potential of the Niobrara shale;
- Creating 3-D subsurface structural and stratigraphic models by interpolating among sparse 2-D seismic lines and well control information in the AOI;
- Identifying the measurements and attributes that correlate with a more productive Niobrara reservoir, and then creating a geo-statistically derived map of relative productivity within the AOI;
- Establishing an ‘environmental baseline’ within the AOI, noting the presence of pre-development vegetative distress, trace surface hydrocarbons, waterway contamination, and habitat exclusion zones;
- Highlighting areas worthy of additional G&G study and investment, including areas that would benefit from 3-D seismic acquisition.
The full complement of NEOS’s sensor systems would be used on this survey – gravity, magnetic, hyperspectral, radiometric, electro-magnetic – and all newly acquired data would be integrated and interpreted with existing geoscience datasets, including well logs, production histories, regional maps, and seismic data. NEOS hopes to begin acquiring data for the program in 2Q2012 and deliver final results to the program’s underwriters by the end of the year.