Lasers prevent oil blow-outs
22 Aug 2000
We're used to thinking of lasers as destructive tools: cutting and etching in the real world, causing spectacular explosions in generations of science fiction films. But new research from the University of Reading could give the much-maligned but increasingly pervasive coherent light a new role - preventing explosions at oil wells.
Physicist David Waterman has developed a system which uses laser light to detect and analyse gas bubbles in drilling slurry. These bubbles form when the tip of the drill approaches a gas pocket - the drill relieves the pressure of the gas as it pierces the pocket and the gas rushes out in bubbles, exactly like the bubbles that form when a beer can is opened.
This gas is far more dangerous, however. If the bubbles aren't spotted, and the pressure of the drilling slurry increased, the gas escaping from the pocket could cause a catastrophic blow-out and explosion.
Waterman's invention, which is described in the current issue of the Institute of Physics' research journal Measurement Science and Technology, illuminates the volume of drilling slurry around the drill tip with sheets of laser light. Any bubbles in the slurry show up in the sheets of light like smoke in a projector beam. Measuring the time interval between bubbles appearing in adjacent laser sheets determines the bubbles' size and speed, and the deflection of light through the bubbles indicates the optical properties - and therefore the density and composition - of the gas.
So far, Waterman's researchers have only tested the system on a laboratory scale, using falling water droplets to mimic the behaviour of gas bubbles. However, their success with these tests leads Waterman to believe that the technology could be deployed commercially within two years.
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