This one is a blast from the past.

It is Project Gasbuggy, or an Atomic Energy Commission experiment in conjunction with the El Paso Natural Gas Co., and the U.S. Bureau of Mines and Department of the Interior to fracture stimulate the Lewis Shale for tight formation gas in Rio Arriba County, N.M., 55 miles east of Farmington.

Stage count? One. There was no proppant. Instead the test was a 29-kiloton nuclear warhead detonated in December 1967 at 4,240 ft below the surface. The nuclear device was twice as large as the bomb used on Hiroshima, Japan, during World War II. As is usual with fracture stimulation, there was a seismic array to track the Gasbuggy event with seismic monitoring extended out hundreds of miles from the test site.

Worries about a potential nationwide energy shortage involving natural gas served as a rationale for the project. New Mexico’s Project Gasbuggy was part of Project Plowshare, or an effort to repurpose nuclear weapons for peaceful application that originated in 1957. The power of nuclear energy was proposed as a solution for extracting tight formation gas. In all, Project Plowshare featured three tests, including the larger and more widely known test at Project Rulison east of Grand Junction, Colo. The third and last test occurred at Rio Blanco, Colo.

In theory, the detonations would create artificial cavities for the accumulation of tight formation natural gas. This unusual program was an early day thematic precursor to the horizontal/directional drilling and multistage fracture stimulation treatment that has boosted U.S. natural gas supply to levels well beyond domestic consumption.

It is also an illustration that the concept of fracture stimulation for hydrocarbon production has existed in various forms for decades and incorporated different techniques reflective of the technology of the time. In the early days, stimulation was part of an openhole completion that used explosives, such as nitroglycerin, delivered via torpedoes assembled on the rig platform and lowered by wireline to the pay zone.

New Mexico’s Project Gasbuggy was the first of three nuclear experiments. The detonation created a 78-ft cavity that collapsed into a rubble-filled chimney. Scientists drilled a borehole in 1968 and performed gas tests regularly until 1976, at which point the project moved to site restoration.

The second test, Project Rulison, occurred 50 years ago in September 1969 on Battlement Mesa in Garfield County, Colo., and incorporated a 43-kiloton device, three times the size of the nuclear device used at Hiroshima. Rulison also generated a 70-ft cavity and another rubble-filled chimney upon collapse. Reentry drilling began in April 1970 and production testing for natural gas occurred through April 1971, at which time the project was abandoned for remediation.

At Rio Blanco, about 50 miles north of Grand Junction, Project Plowshare moved to multistage fracturing when three 30-kiloton devices were detonated in May 1973 in the upper Williams Fork and lower Fort Union formations, followed by a reentry well to the top of the chimney in 1973 and a second well to the bottom of the chimney in 1974. In all, the site produced 125 MMcf of natural gas.

Of note, the three nuclear devices were detonated almost simultaneously and created three independent cavities that were not connected. It turns out the fracture stimulation zone was confined to the area around each detonation and did not extend out as far as predicted.

While Project Plowshare generated accessible natural gas, the high temperatures cooked the gas, lowering its Btu content. It was the second issue that brought the project to a close. The natural gas was radioactive.

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