Carbon fiber drill pipe field tested

World Oil, Feb, 2004 by Robert E. Snyder

Carbon fiber drill pipe field tested. A new type of lightweight drill pipe, made of space-age carbon fiber composites rather than traditional steel, is a step closer to becoming a major government-industry R&D success story. The US Department of Energy's National Energy Technology Laboratory (NETL) recently announced that the composite drill pipe has been successfully tested in a horizontal gas well in Oklahoma. The pipe, developed by Advanced Composite Products and Technology of Huntington Beach, California, proved it could withstand commercial drilling operation stresses.

The flexible pipe is manufactured by winding graphite fibers and epoxy resin around a spindle. The composite tube is cured, and the supporting spindle is removed. The pipe is machined, and then coated to resist abrasion. Developed under a $2.82 million, five-year contract with the Energy Department's Office of Fossil Energy, the drill pipe could be the next major technical achievement emerging from the joint government-industry natural gas research program.

The field test was conducted in mid2003 in Le Flore County, Oklahoma, at a depth of 1,385 ft in a hard/extremely abrasive formation. Unlike field tests in late 2002, which used rotary tools to re-enter existing wells, the latest test was conducted in a new well using air-hammer drilling to propel the 2.5-in. pipe. The air hammer severely challenged the pipe's fatigue life, mechanical strength, and ability to deal with stress, NETL said. After a week of drilling, the pipe showed little wear.

While the price of the composite pipe is currently about three times the cost of steel pipe, researchers are working to reduce this cost. They also plan additional tests in coming months.

The carbon fiber makeup of the new pipe could also be a major step toward developing "smart" drilling systems. Future work will include embedding wire in larger, 7-in. composite drill pipe. The contact is: www.fossil.energy.gov.

ROBERT E. SNYDER, EXECUTIVE ENGINEERING EDITOR snyderr@worldoil.com