Later this month, on March 23 and 24 to be exact, the 9th Annual SPE ICoTA Conference and Exhibition will be held in The Woodlands, Texas. It promises to be an outstanding event.
Kicking off the conference on Monday, March 22, is a 1-day short course conducted by CTES President and coiled tubing expert extraordinaire, Ken Newman. The course will detail all the latest applications of coiled tubing in drilling, competitions, production and workover operations, and there are a bunch. To find out what's new in coiled tubing (CT), I talked with ICoTA Director, Teoman Altinkopru of Schlumberger.
From its early beginnings about 10 years ago, coiled tubing technology and applications have steadily grown as operators discover how valuable and versatile it is to have the capability to apply hydraulic horsepower at the workface. Teoman's list includes,
* CT intervention services, including snubbing.
* CT hydraulic operations such as scale and debris removal, milling jetting, etc.
Blaster services have been out there for some time, and it is particularly effective when there is hard scale that cannot be milled, he said. Blasting it away with beads is very effective. Besides cleaning scale and debris blaster tools give us high hydraulic horsepower BHAs that can be used for matrix treatments.
* CT as a conveyance medium for logging, testing, perforation, running and setting completions, etc.
* CT pumping services including cementing, acidizing, fracturing, gravel pack deployment and formation treatment. Growth in matrix treatments has approached 50% over 2002, all attributable to CT markets.
* CT production testing, including deployment of electrical submersible pumps.
* CT pipeline intervention and maintenance.
* CT abandonment services have been growing in the Middle East, and North America. It can be done without a rig, much more efficiently and cost-effectively, but will still fulfill all the requirements. Abrasive jets can be pumped to cut downhole tubulars.
* CT drilling and fishing.
I asked about CT drilling, which had a brief flurry of activity in the 90s, but which, from my perspective, has been fairly quiet of late. Teoman laughed. "We have a very different perception about CT drilling," he said. "Although it didn't take off the way everyone wished it would, it is certainly not dead. In fact this year compared to last year there has been a tremendous growth in CT drilling applications. There are a number of projects around the world such as North America, Middle East and Far East Asia. A couple of important records have been set by CT drillers. In the past 12 months we have achieved the deepest kick-off (at 15,000 ft (4,575 m) in Latin America); a trilateral well drilled in North America (land); and the longest UBD lateral (5,700 ft (1,738 m) in the Middle East)."
Convinced, I decided to look into CT developments to see what drives this burgeoning business. The one-word answer - speed. And in deepwater, the expression, "Time is money" is particularly apropos. Being able to go into and pull out of a well without making connections is much more efficient, inherently safer, and less costly than conventional operations involving jointed pipe, and of course, CT is a much more versatile tool than wireline or slickline because it can accomplish a broader range of tasks on a single trip into the well.
However, an inherent problem with deploying CT, particularly in deviated holes or horizontal laterals is lock-up. Today, it is believed that CT Tractors can provide enough pull to overcome lock-up. Since lock up is precipitated by frictional forces in opposition to the downward axial movement of the coiled tubing, any tractor that can pull enough to overcome these forces can prevent lock-up from occurring.
New materials are being tested. Several initiatives have been tried to introduce composite coiled tubing, and metallurgists are constantly trying to improve such attributes as fatigue strength, corrosion resistance, and so on. "Smart" CT which includes an embedded wire or fiber conductor, has been developed and tested, but not commercialized. To be successful, it must prove to be a more cost-effective solution than e-Coil which is presently the conventional way to provide downhole power and data transmission. The market will drive the adoption of these materials.
CT is inherently safer. Because no connections are required, there is less chance for loss of well control, and no personnel are required in high-hazard areas of the wellhead. Hole entry and exit is more efficient, because there is no need to stop to make connections. A broader range of services can be offered, including drilling, logging, perforating, pumping and completion services and a wide variety of well remedial work such as corrosion or scale removal. Coiled tubing units are lighter and more compact, making them easier to deploy on satellite platforms, or between decks on large production platforms. On land, CT units can often travel when rigs are restricted by frost laws. And land CT units can mobilize and rig up much faster than workover rigs.
Two new coiled tubing units, from Varco and from Stewart & Stevenson, will be on display at ICoTA 2004. With more than 50 exhibits and a program packed with practical, informative papers, this year's ICoTA is a must-see event. See you there!