Objective
There is a market need for the development of a new method of repairing or strengthening pipelines transporting hydrocarbons both in European waters and offshore/onshore worldwide. Traditional repair methods involving hyperbaric welding or mechanical connectors require cutting the pipeline and are costly and time consuming. Alternative schemes using split sleeves bolted around the damaged pipe are currently viewed as temporary repairs and can only be applied to a restricted range of defects.
The stressed grouted clamp offers a repair scheme which is low cost, quick to install and overcomes the limitations of current clamp repairs. The technology is a direct and simple extension of a concept used by Wimpey Offshore for repairing jacket structures. For pipeline applications, prestress can be applied through a clamp to induce hoop compressive stresses in the damaged area. This gives scope to make damage safe and economically, and even to extend current defect acceptance levels.
The project will be carried out jointly by Wimpey Offshore and British Gas plc Engineering Research Station. The work is divided into five phases. The progress towards meeting the project aims will be assessed at the end of each phase and the content of subsequent phases of the work may be modified/updated to incorporate any new findings. The overall project duration is 38 months.
PHASE 1: ENGINEERING ASSESSMENT AND DESIGN
Phase 1 of the work will initially entail a survey of defect types, quantification of pipeline geometries and loadings, a review of possible clamp configuration and identification of a preferred clamp arrangement. Structural design and verification analyses of the preferred clamp will then be carried out.
Fabrication specifications and a detailed workscope for the testing in Phase 3 will also be prepared.
PHASE 2: PREPARATION OF INSTALLATION PROCEDURES
Phase 2 will involve the preparation of installation procedures and the determination of time and cost estimates for the installation operations.
PHASE 3: LABORATORY TESTING
Laboratory testing will be carried out to confirm the predicted behaviour of the repairs. It will be used to verify the state of stress in the pipeline prior, during and on completion of the repairs. Results will be correlated with analytical work in earlier phases. The extent and need for testing will be assessed in the light of the clamp configuration established at the end of Phase 1. At present it is envisaged that a programme of 9 tests will be performed, considering both static and fatigue loading.
PHASE 4: UNDERWATER TRIAL
Phase 4 will involve an underwater assembly of a repair to provide a practical demonstration of the system and to test the proposed installation procedure.
PHASE 5: MARKETING
Although marketing of the repair system will be planned in detail in this phase, much effort in this direction will have already been carried out. On completion of Phases 3 and 4, the techniques developed will require further marketing effort to make the indsustry aware of the
availability of the technology.
Programme(s)
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
London
United Kingdom