PART I. HISTORY OF COLD WAR NUCLEAR FRAC'ING IN THE US

To alleviate perceived natural-gas shortages, the US detonated nuclear devices between 1967 and 1973 to test the fracture stimulation of tight gas sandstones. The shots, conducted in the San Juan and Piceance Basins, were part of the Plowshare Program and evolved as a result of weapons-related nuclear tests. The Plowshare tests were industry – government partnerships, and all three – Gasbuggy (12/10/67, Bloomfield, NM, 29 kt fusion detonation), Rulison (9/10/69, Parachute, CO, 43 kt fission detonation), and Rio Blanco (5/17/73, Rio Blanco, CO, three simultaneous 33 kt fission detonations) – were conducted in Upper Cretaceous strata and resulted in high-permeability rubble-filled cavities (“chimneys”) surrounded by fractured reservoir rock. Radioactive glass “puddles” formed the floor of the chimneys – the result of vaporized rock that condensed and flowed down the sides of the detonation-produced cavity.

The tests were technical successes. Two of the chimneys were ~350 ft high and had a ~150-ft diameter; fractures extended as much as 400 ft away from the chimney into the reservoir. No radioisotopes escaped to the atmosphere as a result of the shots. All the tests resulted in increased production rates and EURs (estimated ultimate recovery) compared to nearby conventional wells. However, CO₂, ⁸⁵Kr, and tritium (mostly in co-produced water) contaminated the early flared gas. For production, the CO₂ could be separated, the tritium could be re-injected or reduced using boron shielding or specially designed explosive devices, and/or the radioactive gas could be comingled with conventionally produced gas or burned in remote areas, increasing radioactivity levels 1% to 2% above background.

In 1970 the National Environmental Policy Act went into effect, requiring the Atomic Energy Commission to publish possible off-site consequences of the Rio Blanco test. If that test and subsequent small field-scale tests were successful, the environmental impact statement proposed 5665 nuclear-frac’d wells in the Piceance, Uinta, and Green River Basins with three to five devices per well. The last development shot would occur in 2017.

Despite the successes, the gas produced by the nuclear-frac’ing tests was never marketed, and Plowshare funding ceased in 1975, the victim of societal fears of all forms of nuclear explosions.