Volume 3, issue #11 - 03-04-1998

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Study set up to use lasers for drilling

Feb. 24, 1998 The Gas Research Institute (GRI), the U.S. Air Force and the U.S. Army have started a new research program to convert "Star Wars" defence technology to industrial use, which may soon produce a laser drilling rig.
"We can see something like this being field-tested within five years," said Darien G. O'Brien, director of engineering at Solutions Engineering in Lakewood, Colo. He's one of the principal investigators in the research program managed by GRI, with the Colorado School of Mines as primary contractor.
The institute is investing $600,000 in the initial two-year program to determine the feasibility, costs, benefits and environmental impact of laser drilling and completions. Although the research is in its infancy, participants already are visualising a downhole laser machine for drilling, laser-assisted bits for both conventional and slim-hole applications, laser perforating tools and laser orientation devices for both side-track and directional drilling.
The lasers with which they're experimenting are not the puny tools that the drilling and mining industries rejected in the 1970s as too weak to cut through rock.
One now being tested is the chemical oxygen-iodine laser (COIL) developed by the Air Force for tracking and destroying missiles. Its precise control of "wave- length and beam-length" could eliminate problems with well control, side-tracks and directional drilling for gas wells at depths of more than 15,000 feet, GRI officials said.
Another is the mid-infrared advanced chemical laser (MIRACL), originally developed for shipboard defence against aircraft and rockets and designed to burn holes in enemy missiles. According to an army researcher, it "blew a way through" a rock "sandwich" of sandstone and shale in a matter of seconds in a recent test by Phillips Petroleum Co. scientists investigating the use of lasers to perforate wellbores.
Lasers cut through rock -- and virtually any other material -- fast. "It could drill a well in 10 hours vs. 10 days with a conventional rig," O'Brien said.
And it can do so without fatiguing the outer edge of the rock the way drill bits do. A laser drilling machine would not need drilling mud to cool a bit or to carry away cuttings, because the laser can vaporise rock.
Solutions Engineering is working with Phillips to determine if the COIL's beam can be transmitted through an optic fibre to cut one-inch holes through rock, which would bring a new -- and smaller -- dimension to slim-hole drilling. Because lasers seem to sear through rock without weakening the surrounding material, there may be no need for casing to shore up weak sections of even larger wellbores.
That apparently would eliminate the most expensive expendable items -- drilling mud, pipe, bits and casing -- used in conventional drilling while greatly reducing rig time and some environmental problems.
"A lot of barriers have to be overcome," Parker acknowledged. " It's a high-risk undertaking, but it has good potential." The cost of lasers developed bythe military runs into "tens of millions, " though adaptations for drilling would be less expensive.