REASSESSING THE OIL SANDS OF ALABAMA

Although the hydrocarbon resource potential of the Mississippian-age Hartselle Sandstone in northwestern Alabama has long been known, the most recent comprehensive resource assessment was conducted over 25 years ago. Geological Survey of Alabama (GSA) Bulletin 111 (B 111) estimated that Alabama’s surface and subsurface oil sands deposit within the Hartselle sandstone contains up to 7.5 billion barrels of hydrocarbon, with approximately 350 million barrels within 50 feet of the surface. Concentrations of hydrocarbon vary significantly; this variation is not yet well understood. No commercial development of these resources for the purpose of extracting oil has occurred to date, owing to various economic and limiting technological factors. However, with the growing desire for North American energy independence, interest in this resource has recently increased. Thus, the Alabama Oil Sands Program (AOSP) was established at the GSA and the State Oil and Gas Board (OGB) of Alabama in early 2014 to provide a focus for an updated resource assessment within Alabama.

Work within the AOSP has included a comprehensive review of existing data at the GSA and OGB, including data from wells, cores, and field notes. Fieldwork has commenced, building on previous work of B 111. New cores are being collected and added to existing cores for analysis. Testing includes porosity, permeability, and chemical analyses of the rock and bitumen, with particular attention to data that would inform decisions about feasible economic development. Other technologies, such as an emerging technique utilizing Ground Penetrating Radar (GPR), are being explored to better locate bitumen concentrations within the Hartselle sandstone. Current reservoir models and reserve estimates will then be recalculated using up-to-date methodologies. With information about newer surface and in situ extraction technologies that could be economically employed on small- to medium-sized deposits such as this, these updated models will allow for a comprehensive assessment for the potential development of the oil sands of Alabama.