Drilling developments

	Vol. 225 No. 2
ROBERT E. SNYDER, EXECUTIVE ENGINEERING EDITOR

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 mid-2003 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.

Record-breaking performances. Two offshore operators have set new drilling records in the Gulf of Mexico and offshore Mauritania, West Africa. In the US Gulf, ChevronTexaco and Schlumberger Oilfield Services announced new measurement-while-drilling (MWD) and logging-while-drilling (LWD) depth and pressure records for the Gulf, while drilling the operator's deepwater Tonga Exploratory Prospect in Green Canyon Block 727, in 4,695-ft water.

TVD of 31,824 ft was reached, exceeding the previous depth record by 700 ft, with a maximum-recorded downhole pressure of 26,138 psi in Tonga 1. Schlumberger delivered continuous real-time surveys, allowing the well trajectory to be kept on target during the entire drilling/logging process. The tools reportedly functioned flawlessly under the extreme depth/pressure conditions.

The contractor used a patented, high-pressure arc VISION675*, 6-3/4-in. drill collar resistivity tool and PowerPulse* MWD telemetry system to acquire data while drilling. The high-pressure OBMI* OilBased MicroImager tool, along with the Xtreme* high-pressure, high-temperature well logging platform, were used to complete the formation evaluation program. Drilling operations for this record-setting well, 150 mi southwest of New Orleans, were conducted from Transocean's Discoverer Deep Seas drillship. (*Mark of Schlumberger).

   Offshore Mauritania, Smedvig's deepwater drillship, West Navigator, set new records for the country while drilling the Tiof West well on the Chinguetti field for operator Woodside. From arrival on location until the drilling was completed at 2,992-m (9,814-ft) TD, Navigator drilled 1,641 m in a record breaking 5.3 days, including setting and testing the BOP at a water depth of 1,351 m.

Smedvig says West Navigator is one of the industry's most advanced drillships. It is equipped with a dual derrick, which enables drilling/completion operations to be performed simultaneously, significantly increasing drilling efficiency. The rig is presently drilling three wells for Woodside offshore Mauritania.

Underbalanced drilling with coiled tubing. BJ Services Co. has announced another successful drilling project of its special Drilling Using Coiled Tubing (DUCT) technology for a third onshore well in Emmen field in the Netherlands for Nederlandse Aardolie Maatschappij (NAM). All operations relating to the underbalanced drilling on Emmen 8ST were completed in seven days. BJ drilled a 466-ft (142-m) horizontal section at a maximum depth of 15,573 ft (4,748 m) TMD and at a maximum measured temperature of 146°C. Throughout drilling and completion, gas was produced, and it now flows at 500 Mm 3 /d at 674 psi.

Previously, BJ successfully drilled two onshore wells in Coevorden field for NAM. About 70 people from five countries teamed up to drill Coevorden 16 and 17b. The project drilled a 1,650-ft (500-m) horizontal section in a fractured carbonate formation with a BHP of 4,800 psi, at 220°F (104°C). BHAs and hands-free pressure deployment technology were provided by BJ Services Co. Canada. BJ's base in Emmen provided the CT drilling unit, mast structure, pump systems and the operational team. Work reels suitable for the CT length, 14,435 ft, at 2 3/8 -in. OD, were mobilized to location with a 10,000-psi BOP. The wells were drilled underbalanced using KCl brine and nitrogen.

Gas production commenced shortly after drilling into the first fracture system on Well 17b, and increased with each fracture encountered. Drilling and deployment were performed with high surface gas rates and wellhead pressures of 4,000 psi. Two lateral sections were drilled for the second well. One extended 1,729 ft and the other 1,128 ft. The well flowed gas during drilling and deployment and contained 500 – 1,500 ppm sour gas. All operations were performed in a live well environment with returns handled by The Expro Group. More than 260 DUCT projects have been completed in Canada by BJ. The three operations in Holland in 2003 mark the first comprehensive international application of the technology.

Deepwater study. Gulf Research, a subsidiary of Gulf Publishing Co. has just released its “2003 Deepwater/Deep Shelf Technology Needs Assessment” study. Results of the study, which surveyed some 200 individuals in exploration, drilling, completions and production job functions, will provide users data on how industry prioritizes over 60 major technical needs in deep water, ultra-deepwater and deep shelf plays. Interested subscribers should contact Lanie Finlayson at lanie.finlayson@gulfresearch.com.