Jee was contacted by a client who suspected there may be an outwards dent and gouge in one of their major pipelines.
Our engineers were asked to define acceptance criteria for possible dent and gouge defects, both on and away from girth welds, to allow for divers to safely carry out a close inspection of the actual pipeline damage.
Our team have significant experience in defect assessment combined with expert analysis and testing skills.
The analysis was carried out using the following methodology:
- A finite element (FE) model of the pipe in the undented condition was developed and axial and hoop stresses were applied
- The denting process was simulated and the behaviour of the pipe after denting was assessed
- A check calculation was completed in accordance with API 579
- The results of the calculation were compared with FE analysis to identify weaknesses in the code, and modify and strengthen results as required
- Following this, the findings were brought together to develop acceptance criteria.
The analysis results aided the inspection process by demonstrating that the risk to divers was minimal, based on preliminary inspection data and a close inspection of the dent and gouge defects could be completed safely.
Subsequently, our client was able to deem the pipeline fit for service, avoiding unnecessary and expensive repair and replacement work, saving our client substantial costs.
For more information, visit www.jee.co.uk/integrity-management
To contact our Head of Integrity Management, Graham Wilson, email graham.wilson@jee.co.uk, or call +44 (0)1732 371 371.
Jee Ltd
