On a butte above New Mexico's Leandro Canyon last week, chilled ob servers fell silent as a voice on the public-address system reached the end of the countdown. For a tense moment, nothing happened. Then the earth jolted underfoot and a dull, distant boom was heard, followed by a second, more gentle, rolling shock. Someone shouted: "We did it! We did it!" Hand shakes were exchanged all around. The U.S. had successfully set off the first nuclear explosion sponsored jointly by the Government and industry.
Detonated 4,240 ft. below the surface, the 26-kiloton nuclear device was the key tool of Project Gasbuggy, a venture financed by the Atomic Energy Commission and the El Paso Natural Gas Co. and designed to increase natural-gas output. The blast was intended to shatter a large portion of the 285-ft.-thick layer of gas-bearing sandstone lying beneath the Leandro Canyon, thus releasing gas that is tightly locked within the rock. 35-Story Cavity. Ordinarily, gas is obtained simply by drilling a well into a formation of gas-bearing rock. Natural underground pressures then force the gas through pores in the rock into the well casing, enabling producers to tap large natural-gas reserves with relatively few wells. In large areas of New Mexico, Wyoming, Colorado, Utah and Arizona, however, much of the natural gas is held in relatively nonporous rock that prevents the flow of all but small quantities of gas into wells, making them uneconmical to drill and operate. Engineers have increased the flow of these wells by fracturing the surrounding rock—eit|er by forcing fluid under high pressure! into the well or by underground nitroglycerin explosions. But the resulting increased flow of gas through the fractures relatively short lived and in some leases is not worth the additional cost.
Last week's nuclear explosion, on the other hand, should have produced such extensive shattering and cracking, according to AEC experts, that as much as 70% of the gas i in the surrounding rock should flow into the well over a 20-year period, cotnpared with only 10% that would be recovered by hydraulic fracturing or nitroglycerin blasting. Within a minute after the searing blast formed a 160-ft.-diameter cavity in the earth, they calculate, the roof of the cavity should Save begun to collapse (TIME, Nov. 3), eventually forming a chimney of fractured rock as tall as a 35-story building. In addition, cracks should have radtiated out for hundreds of feet beyond the chimney, providing routes for gas; flow.
300 Trillion Cubic Feet. Although preliminary instrument checks at the site indicate that th| subterranean chimney is already filial with gas, several months will pass before scientists can determine how successful Operation
Gasbuggy really is. After drilling a well to the top of the chimney, they will tap off gas freed by the explosion and test it for radioactivity. If the radioactive contamination is low enough for the gas to be usable without extensive —and expensive—purification, and if the gas continues to flow into the well in volume, the U.S. may well be on its way to tapping the 300 trillion cubic feet of natural gas now tightly locked beneath the surface of the earth.