In-Line Quench and Temper Technology Applied to CT Improves Safety and Reliability in Extended Reach U.S. Shale Operations

Abstract

Abstract In unconventional resource plays across the United States, lateral well sections are being extended beyond 10,000-ft. The increased application of larger coiled tubing (CT) in 2.375-in and 2.625-in diameter for operations in wells with mid-to-high pressure has pushed the reliability envelope for conventional CT strings. Lower expected life, while the tubing remained within safe working limits, restricted the Operator's completion and clean out options, which acted as a potential barrier to longer lateral intervention. The performance of CT Interventions in complex extended reach wells with 10,000-ft+ laterals is presented in field case studies detailing extended lateral reach, average service life with statistics at retirement, and common failure modes. The manufacturing of CT strings with improved reliability, life, and reach capabilities has been paramount to extending the limits of CT applications. Well Operators and Service Companies have embraced newer CT technologies and highly engineered string designs that can perform safely in challenging well conditions. The latest technological innovation in the CT manufacturing industry is the implementation of an in-line quench and temper (Q&T) process. The Q&T process enhances the overall CT life and predictability by producing tubing with more uniform microstructure throughout its entire length, increased material strength, and improved bend fatigue performance. When the Q&T product is combined with rapid-taper strip technology and iterative CT design methodology, unique CT string configurations can be produced that achieve unprecedented well lateral reach with improved service life. The combination of these factors enables the safe application of CT with greater diameter to wall thickness ratios (D/t) and increased wall thicknesses. Heavy CT walls including0.276-in which is the thickest used historically in CT interventions, are being deployed, all while satisfying weight constraints, pressure ratings, tensional load limits, and fatigue performance requirements. Actual field operations using this Q&T CT technology have experienced overall increased average running footages of 40%-60% compared to conventional grade strings. This performance has resulted in lower CT replacement rates, creating a cost- effective and time-saving solution for well intervention and drilling operations. As new horizontal drilling and completion technologies are developed and utilized in the industry, CT manufacturers and Service Companies will continue to innovate and provide engineered solutions that enable coiled tubing to be a robust, safe and reliable technology in the toughest environments and on the most critical projects.