The coiled-tubing (CT) industry has experience unparalleled growth in the past year, driven directly by the massive expansion in multistage-fracturing operations in North America. Various sources estimate that the US consumed 50% of the world’s CT in the past 12 months, helping to contribute to a massive 80% growth in product coming off the CT production lines.
The growth in the United States was fueled primarily by three applications: milling out composite plugs, milling out fracture-sleeve ball seats, and toe shoots (the name given to the first perforating operation before plug-and-perforate operations). Because toe shoots take place without any pressure on the well, the amount of CT life consumed by fatigue during the operation is small. Plug or seat milling, on the other hand, takes place after fracturing operations are complete and with the wellbore fully pressure charged by the formation; therefore, the CT life consumed by fatigue is high. Superimposed over the wellbore pressures are the pressures arising from circulating fluids through the CT and the milling assemblies. In some of the higher-pressure shale plays, CT strings last only for a few jobs.
Accordingly, any technology that reduces the superimposed pressure could lead to longer CT life and potentially to lower completion costs. Two of the papers selected for this month’s issue involve new technologies that might be helpful to operators in this respect.
However, of possible greater concern to CT companies in North America is the fact that CT use is now clearly dominated by well-completion operations, or, to put it another way, by rig count. Until recently, the CT intervention business was primarily remedial in nature and, thus, was partially cushioned from the extreme cycles experienced by drillers. However, in North America, a change has already arrived and, with gas prices at historic lows, CT service companies, CT pipe manufacturers, and CT equipment manufacturers probably need to prepare for the same swings that the rest of the well-construction industry is used to.
Read the paper synopses in the June 2012 issue of JPT.
John Misselbrook, SPE, is senior advisor global coiled tubing with Baker Hughes. Previously, he was with Nowsco Well Service Company, which merged with BJ Services in 1996. Misselbrook has worked in various operational, engineering, research, and management roles involving CT in the North Sea, Canada, Southeast Asia, and theUnited States. He was a member of the original team of engineers involved directly in the development of improved engineering techniques for underbalanced drilling in western Canada in 1991. Misselbrook subsequently became responsible for Nowsco’s initiative to develop underbalanced-drilling technology by use of CT. He holds several US patents and has authored several SPE papers on the use of CT. Misselbrook is a mechanical sciences graduate of Cambridge University. He served on the 2008 and 2009 SPE/ICoTA Coiled Tubing and Well Intervention Conference Committees and serves on the JPT Editorial Committee.