Browse Prior Art Database

In-situ Coating Extrusion2014-08-01

IP.com Disclosure Number: IPCOM000238152D
Publication Date: 2014-Aug-05
Document File: 2 page(s) / 64K

Publishing Venue

The IP.com Prior Art Database

Abstract

Internal liners are used to rehabilitate corroded pipelines. Several pipeline liner products are composed of low-strength thermoplastic materials which are highly corrosion resistant. Existing liner designs insert the liner into a previously fabricated pipeline system. An internal coating of these thermoplastic materials could provide similar levels of corrosion resistance. An in-situ approach would be accomplished through use of a pipeline coating extruder that would be positioned behind the internal line-up clamp assembly, thereby enabling pipeline construction and coating installation activities to occur at the same time. The liner would not be pulled through the pipeline but would rather be extruded at approximately the same rate that the pipeline is being constructed. The internal coating extruder could potentially be located anywhere along the firing line, between the first welding station and the stinger at the aft of the pipe-lay construction vessel. The invention could also be used onshore as part of a mainline welding arrangement.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 51% of the total text.

ABSTRACT

Internal liners are used to rehabilitate corroded pipelines.  Several pipeline liner products are composed of low-strength thermoplastic materials which are highly corrosion resistant.  Existing liner designs insert the liner into a previously fabricated pipeline system.  An internal coating of these thermoplastic materials could provide similar levels of corrosion resistance.  An in-situ approach would be accomplished through use of a pipeline coating extruder that would be positioned behind the internal line-up clamp assembly, thereby enabling pipeline construction and coating installation activities to occur at the same time.  The liner would not be pulled through the pipeline but would rather be extruded at approximately the same rate that the pipeline is being constructed.  The internal coating extruder could potentially be located anywhere along the firing line, between the first welding station and the stinger at the aft of the pipe-lay construction vessel.  The invention could also be used onshore as part of a mainline welding arrangement.  

DISCLOSURE

Offshore pipelines require excellent integrity and reliability in order meet their service lifetime and to avoid the significant costs associated with subsea repair or rehabilitation.  Internal corrosion represents a major challenge to integrity due to the various corrosive species transmitted within flowlines, jumpers, and long-distance transmission lines.  Various approaches are available to resist corrosion mechanisms, including material selection, chemical inhibition, and internal claddings.  Internal cladding using corrosion-resistant alloys, or CRAs, can provide excellent corrosion resistance albeit at a significant cost outlay.  Non-metallic solutions using thermoplastic liners have become a cost-effective alternative to CRAs that provide an effective barrier between the steel pipeline and the corrosive species within.  The most standard deployment method involves pulling, or “slip-lining”, the polymer liner through the existing pipeline. Originally developed as an onshore rehabilitation technology, it can also be installed into pipelines prior to start-up.  Recently, technologies have been developed to install these liners into reeled pipelines during the initial reeling process so that a fully-lined pipeline is delivered to the field for installation.  Unfortunately, the method has not been effectively transferred to other pipeline installation methods, such as S-lay or J-lay installation, that require offshore welding procedures.  The present disclosure detail...