The Penspen Group has been commissioned by Qatargas, a pioneering liquefied natural gas (LNG) producer, to develop the detailed design for a new flexible grouted clamp and to produce a set of flexible grouted clamps to enable the quick and effective repair of their large-diameter subsea pipelines in the event of damage incidents. Penspen in turn has contracted FoundOcean.

Qatargas engineers identified the flexible grouted clamp concept as a way to repair anchor damage such as dents, gouges and displacement, as part of the development of their emergency pipeline repair system (EPRS). They are now working with Penspen to develop a simple off-the-shelf modular repair system that can be modified to suit a variety of non-leaking damage scenarios.

Pipeline operators may keep emergency repair clamps in case of incidents. These conventional clamps are adequate for the repair of a leaking defect, such as those that may be caused by corrosion. However, they are usually straight and cannot readily be fitted to pipelines that have been displaced and distorted. In addition, they do not necessarily incorporate structural grouts that will support damage and prevent failure of the defect under the clamp. The flexible grouted clamp will address these issues.

FoundOcean has been contracted to provide consultancy services related to the grout selection and the design of the clamp grout delivery system as well as the performance of verification tests.

The development of the flexible grouted clamp has included the development of procedures to quickly and reliably assess the severity of anchor damage to large diameter pipelines including consideration of the presence of any potential denting, displacement, or gouging. In addition the procedures provide damage limits for the application of a Flexible Grouted Clamp. Work will continue throughout the spring with the design due to be delivered in June 2011.

Roland Palmer-Jones, consultant, Penspen Integrity, said: “Penspen is delighted to be working with Qatargas and the grouting experts at FoundOcean on this innovative approach to the emergency repair of offshore pipelines.”