J. Wade Watkins, United States Bureau of Mines
The tremendous energy of a nuclear explosive and the very small size of a nuclear device warrant consideration of utilizing the energy released to stimulate production from relatively non-productive petroleum and natural-gas reservoirs, and from oil-shale and tar-sands deposits. Significant quantities of petroleum and gas are present in many thick, deeply buried reservoirs that have natural low productivity because of low permeability of the formation or high viscosity of the oil. Productivity from such formations cannot be adequately stimulated by conventional techniques of well completion. Also, vast deposits of oil shale lie too deep for economic mining. If these deposits could be adequately fractured the kerogen present might be converted to shale oil through in situ retorting. Studies of the feasibility of using nuclear explosives to produce fluid hydrocarbons from petroleum, natural-gas, tar-sands, and oil shale deposits have resulted in the following conclusions: 1) low-productivity natural gas reservoirs off the best immediate possibility for nuclear stimulation; 2) some petroleum reservoirs may be stimulated similarly; 3) nuclear fracturing of oil shale may permit in situ retorting; 4) conclusions concerning nuclear stimulation of production from deep tar-sands deposits in the United States cannot be drawn because of inadequate knowledge of their occurrence; 5) an actual experiment is needed to determine technical and economic feasibility; 6) radioactive contamination of hydrocarbon fluids is a problem that can be solved by various means, and nuclear stimulation can be conducted safely and within existing regulations; and 7) a test may be proposed and conducted relatively soon on a natural-gas reservoir of low productivity.