RIASSUNTO
Abstract
New design challenges for deepwater, extended-reach and other critical completion operations have limited the use of conventional industry standard workstrings and prompted development of a new Completion Pipe capable of addressing demands for high torsional strength, gas-tight seals and a streamline connection profile.
Tubing configured with premium connections has traditionally been used to perform high-pressure completion operations. As water depths, well depths, and well angles have increased, so have the performance demands for the pipe. Torsional capabilities of premium tubing strings are often limited in these applications. Completion pipe provides the torsional strength and robustness of a high performance tool joint connection with the pressure integrity of a premium metal-to-metal gas tight seal connection.
Innovations in high-performance tubular design as well as step change improvements to existing connector technologies has led to the development of a specialized drill pipe tubular with metal-to-metal pressure seal connections as a new completion pipe option. Maximizing tool joint inside diameter and shifting tube upsets to the exterior are options for minimizing flow restrictions. The dimensional flexibility of these durable, streamlined high performance tool joints provides advantages not seen in typical API tool joints or threaded upset tubing connection configurations. Flexible connection configurations and optimized tubular design satisfy standard completion tubular profiles as well as very specific fit for purpose applications.
The paper offers solutions to completion engineers involved in planning and executing critical completion operations in deepwater, extended reach and ultra-deep wells. This paper presents key tubular design considerations for meeting torsion, tension, hydraulic, pressure integrity and pipe recovery method requirements of critical completion operations. Mechanical characteristics of assemblies and field performance of application specific completion assemblies are presented.
Introduction
With the proven reliability and growing acceptance of eXtreme™ Torque Metal-seal (XT-M™) rotary shoulder connections in drill stem tests, hydraulic fracturing and other critical completion operations, opportunities to optimize pipe and connection design practices to further accommodate critical completion operations are being realized.
Torsional limitations of conventional tubing connections have restricted completion capabilities in deepwater, extended reach, and other demanding well applications. Operating torque requirements can exceed the rated torsional strength of commercially available premium tubing connections. Increased setback requirements for accommodating multiple strings, in addition to costly change-out equipment required when handling those strings, hinder running speeds and add trips where an optimized completion string design can accomplish completion and associated objectives.
The versatility of completion pipe designs save precious setback space on offshore vessels by eliminating the need for multiple strings, while reducing the cost of acquiring and maintaining several strings for a given project. The potentially unsafe and time consuming process of picking up and laying down various strings can therefore be reduced or eliminated. Using one string for drilling and completion processes also improves efficiency and safety by allowing rig employees to setup for one connection without requiring changes to handling tools or handling practices.