Realizing the One-trip Expansion, Single-diameter Wellbore

• Main Author: Waddell, Kevin Karl
• Format: Conference Proceeding
• Language: English
• Published: SPE 2005; Society of Petroleum Engineers
• Subjects: 4.1.2 Separation and Treating; 1.7 Pressure Management; 1.10 Drilling Equipment; 4.2.3 Materials and Corrosion; 1.6 Drilling Operations; 2 Well Completion; 1.14 Casing and Cementing; 4.5 Offshore Facilities and Subsea Systems; 1.1.6 Hole Openers & Under-reamers; 4.2 Pipelines, Flowlines and Risers
• ISBN: 1555639933; 9781555639938
• DOI: 10.2118/96655-MS

AbstractThe provenance of the single-diameter well consists of over 350 commercial installations of solid expandable tubular systems and a concise, yet encompassing development plan. The maturation of expandable technology has led to successful design, construction and testing of individual components and the subsequent subsystem that will ultimately help realize the single-diameter well. This evolutionary step brings the energy industry that much closer to a fundamental change in wellbore construction. The single-diameter well represents a paradigm shift in the way wells are drilled and results in significant benefits that include conserving resources, saving time, and creating a smaller environmental footprint. All of these features result in considerable savings that reflect the practicality of this value-added technology.This paper will explain the overall scope, approach and implementation essential to realizing the single-diameter well. In addition, this paper will explain how the technical development of necessary tools for the single-diameter well brings significant savings to drilling operations. Using business cases, this paper will detail where the value of application is realized. In conclusion, this paper will outline future possibilities for the technology and how it will impact the industry.IntroductionThe legacy of single-diameter technology stems directly from the development of solid expandable tubulars. Extensive and progressive testing by Enventure and Shell has rapidly improved single-diameter technology. Manipulating the diameter of pipe downhole has taken these systems from an emerging technology to a viable wellbore construction option. Incorporating these systems into the drilling design retains wellbore ID and decreases the tapering effect. Developing a process to retain wellbore ID by using these systems in tandem virtually eliminates wellbore tapering. This concept constitutes the premise of the single-diameter wellbore advantage.Proving the ConceptA proof-of-concept well, completed in South Texas by Shell Exploration and Production Company (SEPCO) in July 2002, used one single-diameter section that required two dedicated trips to complete the expansion. The system used conventional expandable technology for the first trip, hydraulically expanding from the bottom up, to achieve the required partial inside diameter (ID). A combination hydraulic and mechanical expansion trip from the top down followed, achieving the final required ID (Figure 1). With the basic construction principles proven, the challenge now was to translate these elements into a practical and more universally cost-effective working system. A project team, consisting of the operator's research group and asset team and the expandable service company, began to move the development beyond the proof of concept stage. First, the team refined the base concept to a slightly different configuration. The improved system concept expands a bell section on the bottom of the expandable casing creating an overlap. This section allows the subsequent string to be expanded and clad inside the bell for hanging and pressure sealing. The remaining liner length is then expanded using a basic pipe expansion method. Expanding the liner top into the previous bell section forms a metal-to-metal seal. The necessity for zonal isolation was identified as a key issue and addressed by underreaming the hole section to provide an adequate cement sheath.Next, team members concurred that the existing post-expanded casing specification and completion scenario were acceptable and turned their attention to system functionality. The numbers of trips to complete an installation and risk mitigation were identified as the two primary considerations directly related to the deepwater environment and spread rate cost. The bell section expansion, main liner section and overlap needed to be consolidated into one trip. Adequate self-contained contingencies also needed to be part of the design.