Remotely activated pipeline spheres isolate subsea line for installation

Journal Article · Mon Aug 01 04:00:00 EDT 1994 · Pipeline and Gas Journal; (United States)

OSTI ID:7089294

Newman, W J ^[1]; Kontou, T Y ^[2]; Aldeen, A

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1. Shell Expro, Aberdeen (United Kingdom)
2. Shell UK E and P, Aberdeen (United Kingdom)

Following the Pipe Alpha tragedy in 1988, Shell UK Exploration and Production (Shell Expro), operator in the UK Sector of the North Sea for Shell and Esso, decided to fit subsea isolation valves to some of its offshore gas pipelines. For environmental, safety and operational reasons, Shell considered it beneficial to avoid flooding the lines with water and instead use a plugging system to isolate the section of pipeline to be cut. Difficulties were presented by a 30-in. pipeline, which had design features that precluded the use of the high-friction pig isolation system developed for other pipelines. Two options were available: development of a pre-inflated high-seal sphere; development of a remotely activated on-site-inflation sphere. The first option was eliminated because of the high wear of pre-inflated spheres along the pipeline to their required location, which could result in leakage of the seal. The remaining option required the development of a through-pipe communication system operating in an environment of gas or liquid, or a combination of both. Shell Expro commissioned Acurite Ltd. to produce a prototype of a remotely activated sphere isolation system. Acurite is a consultancy previously retained by Shell Expro to engineer innovative solutions to a variety of pipeline problems. Acurite had already produced an outline design of an isolation sphere and was confident of overcoming the communication difficulties by adapting an electromagnetic technique it had used in non-destructive testing research.

• OSTI ID: 7089294
• Journal Information: Pipeline and Gas Journal; (United States), Journal Name: Pipeline and Gas Journal; (United States) Vol. 221:8; ISSN PLGJAT; ISSN 0032-0188
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030300* -- Natural Gas-- Drilling
Production
& Processing
030500 -- Natural Gas-- Health & Safety
42 ENGINEERING
423000 -- Engineering-- Marine Engineering-- (1980-)
ATLANTIC OCEAN
CLOSURES
CONTROL EQUIPMENT
DATA TRANSMISSION SYSTEMS
DESIGN
EQUIPMENT
FLOW REGULATORS
INFLATABLE SEALS
INSTALLATION
NORTH SEA
OFFSHORE PLATFORMS
OFFSHORE SITES
PIPELINES
POSITIONING
RELIEF VALVES
SEALS
SEAS
SURFACE WATERS
UNDERWATER OPERATIONS
VALVES