This paper presents an overview of the various components of an emergency pipeline repair system which should be in place in order to act effectively and efficiently during an emergency pipeline repair scenario.
The condition of pipelines during operation is typically monitored by means of external and internal inspections. These inspections allow for planned intervention when a pipeline is found to be deteriorating. A failure to inspect adequately for time dependent threats, or randomly occurring events such as third party interaction, could result in a pipeline failure, leading to a requirement to rapidly return to operation and thus the need for an emergency repair. An Emergency Pipeline Repair System (EPRS) is therefore an essential part of a pipeline integrity management system.
The primary purpose of the EPRS is to ensure that pipeline operators have the necessary level of readiness to allow an emergency repair to be carried out, thus minimising the economic consequences of having a pipeline out of service, whilst optimising the cost of purchasing and maintaining equipment and spares.
In general, pipeline operators will have some emergency repair procedures to cater for unplanned or unexpected incidents. However, to complete an emergency repair efficiently and effectively, the availability of adequate spare materials and timely access to the damage location is required. For a large pipeline network, satisfying these requirements can be challenging.
This paper discusses some basic elements of an EPRS and describes a case study of the development of a risk based EPRS strategy for an offshore pipeline operator. This approach involves the identification of credible hazards that can lead to damage requiring an emergency repair, and identification of repair options. The relative importance of the individual pipelines, in terms of their availability requirement, and the expected time required to complete an emergency repair are then taken into account. This enables the pipelines to be ranked based on the consequence of failure. Pipelines with consequence rankings that are considered unacceptable are therefore highlighted, and EPRS readiness related to those pipelines can subsequently be optimised.
Recommendations for the development of an EPRS for an onshore or offshore pipeline network are also made.