Lab Testing New Microdrilling Technology

As a complementary part of this project, the researchers, incollaboration with U.S. industry, also are developing miniatureseismic instrumentation packages that can be placed inside themicroholes for data gathering. Virtually any microsensor may oneday be able to take advantage of the microdrilling technology.

The technology consists of a standard mining drill bit and oilfield drillout turbine attached to a steel coil that's one inchin diameter, compared to conventional production well drillsused today by oil and gas and other companies that can beanywhere from six inches to more than a foot in diameter.

The steel coil is wrapped around a tubing reel that resembles awater hose holder. The reel can hold thousands of feet of coiland is part of a drilling system that ultimately will occupy aspace roughly 1/20 that of a typical rig, said Jim Albright,leader for Los Alamos' Geoengineering Group. He added the newrig costs about 90 percent less than a conventional rig.

The coil is placed though an injector wellhead, then beginsdrilling holes less than two inches in diameter. The steel coilis flexible enough to drill holes at various angles. Albrightalso said microdrilling realizes additional savings because itrequires only about a barrel of fluid per 1,000 feet of drillingfor lubricating the bit and motor and removing dirt, whereasconventional drilling requires about 40 barrels of fluid per1,000 feet. "In addition to the greatly reduced cost, one of theother benefits of microdrilling is that it can be used to extendexisting production wells," he added.

Several major oil companies are contributing financial ortechnical support for technology development. The Department ofEnergy also is providing financial support for development of amicrohole drilling infrastructure.

Albright said as electronic circuitry continues to shrink insize, microdrilling may one day become the preferred tool forplacing other sensors deep underground to perform an array ofdata-gathering activities, including monitoring soilcontamination and underground nuclear testing.

The microdrilling technology currently is undergoing the firstphase of testing at Fenton Hill, a site located about 40 milesnorthwest of Los Alamos and managed by the Laboratory forresearch. Thus far, the results are encouraging, Albright said.

"We need to make sure that the technology can be used acrossdifferent types of sedimentary rock and that the drilled holesremain stable and don't cave in. After all, the holes beingdrilled are less than two inches wide." The microdrill currentlyis boring through volcanic rock, or tuff, on Fenton Hill.

Albright also said he hopes Los Alamos researchers will be ableto drill down to a target depth of 6,000 feet within the nextthree to five years.

Los Alamos National Laboratory is managed by the University ofCalifornia for the U.S. Department of Energy.