Clamp and overwrap repairs of oilfield pipelines

Several factors influence the selection of a pipehne repair method. Generally, new technologies are not readily accepted by O G operators because, in the absence of established service track records, the risk of hydrocarbon loss in the event of failure is deemed to be imacceptably high. Moreover, the severity of the pipeline damage, location, operating and environmental conditions, fluid composition, cost and urgency for repair aU contribute to the ultimate selection of a repair method. 

Rdiabilitation of Pipelines Using Fibrar-rcanforced Copyright 2015 Elsevier Ltd. All rights reserved. 

Rehabilitation of Pipelines Using Fiber-reinforced Polymer (FRP) Conq)osites 

A well accepted method of repair involving an external fixture is the utilization of mechanical clamps (also known as sleeves) to encase the damaged region. These can be applied for both leak containment and strengthening (Coley and Caraballo, 2011). The clamps arc typically metallic and consist of two-piece flanged shells with oversized annuli that fit over the pipe, with perimeter elastomeric seals for fluid containment. The clamps are fixed together via a series of bolts on the flanges. For underwater applications, they are normally fitted with aluminium anode blocks for cathodic protection. 

While metallic repair clamps have been demonstrated to be effective, there are several drawbacks associated with their use. Firstly, highly corrosive service environments make these metallic repairs susceptible to degradation over time. Secondly, metallic repairs are typically heavy, thus requiring special infrastructure for installation, and sometimes additional pipe supports are necessary after installation. 

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