Oil mining offers the potential for significant additional recovery of oil remaining in reservoirs after primary, secondary and tertiary production methods have been applied. Potential reserves for oil mining techniques within the United States is estimated to include 300 billion bbl of light oil and 200 billion bbl of heavy oil. Projects tested throughout the world have demonstrated the technical feasibility of oil mining. Recent evaluations indicate that this technology is economically competitive with most enhanced oil recovery (EOR) methods.

Oil mining can be divided into two general categories: surface mining and underground mining. Surface mining appears applicable to near-surface reservoirs with low overburden ratio and high oil saturation. Heavy oil and tar sands offer many potential targets for surface mining. Underground mining is applicable to reservoirs less than 3,000 ft (900 m) deep, using the mining-for-access method. Mining for access includes the development of underground space at the base of a reservoir and the drilling of closely spaced drainage wells upward into the reservoir. This mining method produces oil by gravity drainage and is therefore applicable to underpressured reservoirs with adequate oil mobility.

Selection and development of an oil mining project is based on a unique combination of mining engineering, geotechnical engineering, and petroleum engineering parameters and considerations. As with EOR projects, successful implementation of this technology depends on a detailed understanding of the subsurface conditions in the project area. Subsurface exploration programs for oil mining projects must be highly integrated in order to provide useful data for each of the applicable disciplines to perform their respective evaluation and design analyses.

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