Technology Focus: Coiled Tubing (June 2023)
Authors: Ramondenc Pierre 
Published: July 2023

Needless to say, the oil and gas industry as a whole has been riding a rough roller coaster over the past few years. The drop in activity felt at the end of 2019 was made much sharper by the COVID-19 pandemic, which brought investment levels to historic lows. This was followed by a recovery at least as abrupt, and many now believe that we are in for a strong multiyear upcycle. Although positive for our industry, this generates all sorts of challenges, including access to both the human and equipment resources necessary to support that growth.
The notion of cycles is not new to oil and gas; however, the past 3 years have significantly transformed the mindset of most of its actors, who are now chasing any opportunity to reduce waste and increase efficiency of their operations while assessing how they can further reduce their environmental footprint. Coiled tubing has a key role to play in those efforts, with strong arguments for itself: It is used throughout the life of a well, from exploration to abandonment, and its flexibility of use, combined with recent technology developments in pipe materials, real-time downhole telemetry, and specialized downhole tools—just to name a few—opens avenues to perform in a rigless manner many operations that once required a rig and several service lines.
It seems, however, that, like the rest of the well-intervention field, and despite a positive outlook, coiled tubing still hits the same glass ceiling in success rate and activity levels. How to break it was at the center of discussions during the recent SPE/Intervention and Coiled Tubing Association (ICoTA) Conference in The Woodlands, Texas, which proposed to a record attendance a variety of case studies and new technologies and a very dynamic operator roundtable. The technical program confirmed a trend already noticed in recent publications, with coiled tubing expanding once again its operational envelope and proposing new work flows addressing the industry’s wish for efficiency, waste reduction, and digitalization.
One such example is the rapid increase in rigless coiled tubing drilling seen over the past couple of years. The demand for new projects, both onshore and offshore, is on the rise, with always more extreme downhole conditions of low pressure and high H2S content. Paper SPE 210978 provides a detailed review of the best practices to take into consideration when planning and executing such projects, which seem to be familiar in the Middle East. Meanwhile, paper SPE 213666 shows how bit design can play a key role in facilitating deeper reach during coiled tubing drilling operations.
Another area of focus for the well-intervention industry is offshore, where activity is expected to grow significantly in the years to come. While our industry still searches for ways to optimize costs and minimize rig operations—which are costly and time-consuming—papers SPE 212939 and IPTC 23046 offer new avenues, with compelling examples of how well-intervention vessels and catenary operations can enable a wide range of optimized rigless interventions while preserving the use of key downhole technologies.
Lastly, as a testimony to the versatility of coiled tubing, papers SPE 212933 and SPE 212925 demonstrate how coiled tubing can capture a very large workscope in a single mobilization while reducing equipment and personnel footprint and using the most advanced evaluation and intervention techniques. Both papers deal with remediating well-integrity issues, but in very different settings—as part of a fracturing campaign for the former and to enable access to a subsea tree for the latter. Yet they both demonstrate that coiled tubing often can be the cornerstone of much larger work flows and be key in raising the success rate of well interventions across the globe.
Recommended additional reading at OnePetro: www.onepetro.org.
SPE 213666 Coiled Tubing Drilling Advancement With Smallest Shaped Diamond Cutting Element by Syed M. Siddik, Baker Hughes, et al.
IPTC 23046 Real-Time Rigless Intervention With a Catenary Coiled Tubing System To Perforate the Long Horizontal Section of a Well, Offshore Brunei by Azemi Leong, Halliburton, et al.
SPE 212925 Subsea Well Annular Integrity Repair Using Coiled Tubing and Pressure-Activated Sealant by Joel E. Johns, Seal-Tite International, et al.