Microdrilling Technology Advances in Los Alamos Laboratory Field Test

Small-Diameter "Microholes" and Miniature Instruments Could Cut Costs of Future Oil, Gas Exploration

	Microdrilling Technology - Drilling inexpensive, small diameter "microholes" using easily transportable coiled tubing equipped with miniaturized seismic and other geophysical instruments could lead to much cheaper oil and gas exploration.

In exploring for oil and gas in the 21st century, smaller may be better.

The Department of Energy's Los Alamos National Laboratory is announcing this week that recent field experiments have enhanced prospects for "microdrilling" technology - a concept that could offer a revolutionary, lower cost approach to oil and gas exploration.

According to the Laboratory, the new technology currently allows for drilling holes up to 500 feet deep with all the equipment carried on a tandem-wheel trailer pulled by a standard pickup truck. When developed for deep drilling, the technology will replace traditional methods that use massive amounts of equipment, material and manpower, all of which are extremely expensive.

The concept could be a significant step toward futuristic "rig-less" drilling that could reduce the visual impact that has contributed to public objections to drilling in some areas.

Last month, four microholes with diameters two to five times smaller than conventional holes were drilled to depths of 300 to 500 feet in alluvium and lake sediments by staff from the Laboratory's GeoEngineering group. The work was supported by a major energy company in concert with DOE's Natural Gas and Oil Technology Partnership.

Microdrilling technology was highlighted as a likely "success story" emerging from the Energy Department's oil and natural gas research program. According to DOE's Oil and Gas RD&D Programs, released in February 1999, future microdrilling systems could occupy a space roughly 1/20th that of a typical rig and cost about 90 percent less.

Companies using microdrilling would also realize additional savings because the technology could ultimately require only about a barrel of fluid per 1,000 feet of drilling to lubricate the bit and motor and remove dirt, whereas conventional drilling requires about 40 barrels of fluid per 1,000 feet.

The Los Alamos experimental fieldwork showed that drilling small-diameter microholes is both feasible and ideally suited for data collection using miniature sensors. For example, in this experiment Los Alamos scientists used for the first time a microelectromechanical system accelerometer to collect subsurface seismic data.

"Future microholes will be drilled so inexpensively that companies can use them to do things they've never done before," said Earl Whitney, a project leader in the Laboratory's Earth and Environmental Systems Division. "By using the microholes to deploy newly-miniaturized seismic and other geophysical instruments, the industry can study vast areas of potential production at an enormous reduction in cost."

The microdrilling technology is based on the miniaturization of conventional coil tubing techniques that deploy a drill motor and bit on the end of tubing coiled around a spool. The recent test drilled 2 3/8-inch diameter microholes lined with 1 1/4-inch flush joint PVC tubing. Drilling fluids are run through the tubing to turn the motor and drill bit.

In place of the usual large mud tanks needed to capture what's dug out of the ground, much smaller tanks suffice.

"Cleanup is expensive for conventional drilling methods," Whitney said. "By greatly reducing the size of the drilling site, we not only reduce the overall drilling costs but the environmental impact, which can be even more expensive."

The team is developing an even smaller motor and bit system that could allow drilling to 10,000 feet, deep enough to explore most of the world's potential oil and gas reserves. Concurrently, plans include broadening the project's focus to include miniaturization of standard borehole tools used today in drilling operations to study oil and gas reservoirs.

The project is being co-funded by the Federal Energy Technology Center (FETC), a field facility of DOE's Office of Fossil Energy. FETC, colocated in Morgantown, WV, and Pittsburgh, PA, is one of the Federal participants in the Natural Gas and Oil Technology Partnership. The 10-year-old Partnership was formed at Los Alamos and Sandia National Laboratories to offer their scientific capabilities to the oil and gas industry. Under this arrangement, the DOE pays for the scientists' time and the industrial partners share other costs of research and testing.

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For more information, contact:
Kay Roybal, Los Alamos National Laboratory, (505)665-0582, e-mail: k_roybal@lanl.gov

Technical program contacts:
Roy Long, DOE Federal Energy Technology Center, (304)285-4236, e-mail: rlong@fetc.doe.gov
Earl Whitney, Los Alamos National Laboratory, (505)667-3595, e-mail: whitney@lanl.gov