Groove geometry for injection molded polypropylene coated field joints

Abstract

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.

Dependencies are inferred from the claim text.