Our client operates a platform with a 20” offshore to onshore gas export pipeline to transport fluids for onward transmission. The pipeline was designed to be allow the use of spheres for water management in later life. The client conducted a sphere test run which uncovered a number of issues, including the sphere not being received when expected.
Jee was asked to carry out a review of the sphering operations to determine the root cause of the issues encountered during the test run and make recommendations to ensure success with future sphering operations.
The review
Jee completed a review incorporating the following:
Sphere and pipeline design parameters
Jee completed a review of the sphere design parameters such as dimensions and bore passage and temperature capability. This was compared to the pipeline actual geometry and design conditions. Jee developed a detailed pipeline boremap which was used to aid assessment of the suitability of the sphere.
Sphering operation procedures
Jee completed an in-depth review of the operating procedures used for the sphere test run to determine their suitability for the sphering operation.
Operating conditions
Jee completed a thorough review of the operating conditions during the sphere test run, examining the temperatures, flowrates and valve positions to determine adherence to procedures and identify any potential issues affecting the sphere run. As part of this review Jee assessed the sphere differential pressure requirements.
The conclusions
The review concluded the following:
The sphere used was assessed as being compatible with the pipeline geometry and conditions.
Operating procedures were found to be suboptimal, Jee recommended updates required to optimise the procedures for future sphere operations.
Operating conditions during the test run were found to be unfavourable for sphering operations. The outcome of this review fed into the recommended procedure updates.
By completing the reviews detailed above Jee were able to identify the root cause of the issues encountered. The added value for our client was the depth of assessment completed and positive recommendations made to support future sphering operations.
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.