Shawcor Ltd.

2543500 Alberta Ltd.

Magne Skinstad

Ole Thomas Ustad

Adam Wright

Roberto Del Callejo Vargas

Alexandra Sperber

Corentin Lazarus

Marcos Mockel

Pablo Wiesemann

Craig Sloan

In an injection molded polypropylene field joint of an oil or gas pipeline, the three-dimensional geometry of the injection molded/cast coating can have an influence on the stress placed on the line coating during cooling. Specifically, it has been found that molding or casting a coating having circumferential grooves, or other groove geometry, proximal to the interface with the line coating, will reduce line coating failure proximal to the field joint, in particular line coating failure related to the initial spooling/reeling of the pipe.

Groove geometry for injection molded polypropylene coated field joints

A method of coating a field joint, pipe sections for forming a coated field joint, and a coated field joint formed thereby. First and second angular cut backs are provided in the parent coating of each pipe section. The first angular cut back is at an angle of about 30°+−0.5° relative to the longitudinal axis of the field joint, and the second angular cut back is positioned further from the field joint than the first angular cut back. The first and second angular cut backs result in the parent coating having a stepped profile, a step in the stepped profile between the first and second angular cut backs, the step is substantially parallel to the longitudinal axis of the field joint and is often substantially free of indentations. The field joint coating may be injection moulded to have an upstand that is less than or equal to about 5 mm.

Method of coating a field joint

A method of coating a field joint, pipe sections for forming a coated field joint, and a coated field joint formed thereby. First and second angular cut backs are provided in the parent coating of each pipe section. The first angular cut back is at an angle of about 30&#xb0;&#xb1;5&#xb0; relative to the longitudinal axis of the field joint, and the second angular cut back is positioned further from the field joint than the first angular cut back. The first and second angular cut backs result in the parent coating having a stepped profile, a step in the stepped profile between the first and second angular cut backs, the is substantially parallel to the longitudinal axis of the field joint and is free of indentations. The field joint coating is injection moulded to have an upstand that is less than or equal to about 5 mm.

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Orkanger, Norway

Magne Skinstad