Abstract

When a 'cut out' and replacement repair is required on a large diameter high-pressure gas pipeline, safety throughout this complex procedure is of paramount importance. However when this type of repair operation involves a river crossing, with river traffic, and a location close to a populated area with a busy roadway, then ensuring safety is elevated to yet another higher level.

Following an Intelligent Survey of a 36" gas pipeline, a number of severe defects were identified within a section spanning a 50-metre wide tidal river. It was decided to perform a 'cut out' replacement repair to maintain integrity of the pipeline.

Safety and environmental procedures covering all aspects of the work, including the education of the local population on potential hazards, were required to be prepared and reviewed, to allow successful execution of this major task.

Prior to the start date of the repair, required safety measures were identified and action plans to allow their implementation, combined with continuous monitoring were finalized. These covered many interesting areas, including high-pressure hydrocarbon transportation and repair techniques, through to local villagers, river and roadway difficulties.

This dangerous and difficult repair, with highly complex safety aspects, was completed ahead of schedule with no accidents or incidents. This can be directly attributed to thorough and well-planned safety procedures with rigorous monitoring throughout the operation.