Deepwater cold tapping developed for repairs

Journal Article · Sun Apr 01 04:00:00 EST 1984 · Pipe Line Ind.; (United States)

OSTI ID:6635575

Quir, R

Deep tests of cold tapping equipment for subsea pipeline repairs and line modifications have been successfully conducted in Hjeltefjorden near Bergen, Norway, in 462 ft water depth by Total Marine Norsk A/S. The operations were conducted from the Ugland-Comex 1, a DP diving support vessel, by the Kongsberg Vapenfabrikk/Comex Services joint venture. Objective of the cold tapping project was to devise a system that would avoid flooding of a subsea oil or gas pipeline during repair of the line or during modification of the line, such as adding a tee. Principle of the cold tapping method is to insert a plug on either side of the section on which work is to be conducted, thereby effectively isolating both the pipe from the seawater and the section of pipe involved from the fluid moving through the pipeline. Pipeline repair times could be cut by as much as 50% with the cold tapping method. Repairs usually involve either a wet buckle (which produces a hole in the line and forces the operator to shut down production until repairs are made) or a dry buckle, which generally is an obstruction to pigs and a weak point in the line.

• Research Organization: Total Marine Norsk A/S, Stavanger
• OSTI ID: 6635575
• Journal Information: Pipe Line Ind.; (United States), Journal Name: Pipe Line Ind.; (United States) Vol. 211:4; ISSN PLINA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
022000* -- Petroleum-- Transport
Handling
& Storage
03 NATURAL GAS
032000 -- Natural Gas-- Transport
Handling
& Storage
CLOSURES
DEFECTS
DIVING OPERATIONS
EQUIPMENT
EQUIPMENT PROTECTION DEVICES
EUROPE
FIELD PRODUCTION EQUIPMENT
NATURAL GAS WELLS
NORWAY
OFFSHORE OPERATIONS
OFFSHORE SITES
OIL WELLS
PERFORMANCE TESTING
PIPELINES
REPAIR
SCANDINAVIA
TESTING
WELLS
WESTERN EUROPE