Flexible-pipe specialist flexlife is playing the lead role in a JIP (joint industry project) to carry out ground-breaking research that could help extend the future life span of flexible riser pipes.
The Aberdeen company will initially work alongside Chevron, UK Health & Safety Executive, Maersk Oil North Sea, Premier Oil and Technip. Discussions are ongoing with a number of additional organisations that are interested in joining the JIP.
This is thought to be one of the most practical ever undertaken by the subsea sector and will provide a comparison between the original design requirements and capabilities and the actual design and service life capacity of 23-year-old unbonded flexible risers.
The results should help operators avoid costly changing-out of such delivery pipework earlier than required.
In addition, the JIP will be used as a means of validating a number of innovative NDT (non-destructive testing) techniques, cross-referencing the data gleaned with the empirical material characteristics from the subsequent pipe dissection.
Technologies under consideration include flexlife’s own proprietary UT (ultrasound) technique, plus eddy current and radiography.
The various current and future partners will be given access to the data and peer-assessed report, which will inform pipe integrity and methodology and potential life extension of legacy risers going forward.
Craig Keyworth, project manager at flexlife, said: “The JIP is a unique and unprecedented opportunity to test and deconstruct end-of-service risers in a controlled environment.
“In the past, data was based on predicting likely outcomes, but there were never enough older risers to examine to base conclusions on, and the result was a conservative approach to design, service life and end-of-life decision-making.
“The research is ground-breaking in respect of offering tangible data and performance criteria of both the riser as an asset and the individual layer which it comprises.
“If the outcome of this project proves that we are capable of extending the service life of these risers, there will be a multitude of benefits to the industry, specifically economical and environmental.
“We look forward to working with a number of key players on such a significant project for the industry.”
The first batch of risers to be tested are from Premier Oil’s Balmoral field floating production vessel, located on UK North Sea block 16/21. They were first used in November 1986.
Ten sections (120m) in total from two risers – an eight-inch oil export and a four-inch gas lift – were collected for the study, which will focus on pipe performance, end fitting performance and layer/component performance.
The criteria for assessing these three main areas is covered by the API 17J/ISO13628-2 combined standard (January 1, 2009). As part of the study, flexlife is also assessing sections of a “control pipe”, which is of the same design and has never been used.
Balmoral area projects manager Glyn Pritchard said that, with the floater using some of the oldest flexible risers in the North Sea, if not the world, Premier was happy to make samples from the recovered risers available to the industry in order to help build a comprehensive picture of actual riser condition after years in service.