FINITE ELEMENT ANALYSIS OFFERS INNOVATORS BEST TESTS YET
New products and innovations entering the well integrity market have never been tested more thoroughly than they are today, according to subsea specialist, Andrew Mosley, managing director at Aberdeenshire-firm, AS Mosley.
Using ANSYS 3-D finite element analysis (FEA) software, engineers can test the safety of innovations ahead of operations. 3-D FEA uses a computerised modelling system that represents the geometry of the product, including all interfaces and boundary conditions. Once a computer model has been created, the product is tested in a virtual environment for structural capacity in high-temperature and high-pressure environments.
Real-world forces, such as heat, fluid flow, dynamic motion, vibration, mechanical stress and deflection, can be used to predict the behaviour of the product in different conditions. A positive outcome gives developers the confidence to move on to the manufacturing and production phase, knowing that their product is safe. It can also help with product qualification and certification.
Andrew comments: “Our approach is very thorough. Combining mathematical modelling and real-world forces creates analysis with robust and true-to-life predictions. Having used FEA for over 20 years, we always find the results very interesting. Sometimes they are positive, but occasionally they throw up issues, leading to additional product optimisation or redesign. Either way, the process can save a lot of time and money and, more importantly, it can save lives, which is very satisfying.”
AS Mosley recently (April 2017) provided analysis of a 6 3/8” 15000 PSI in-riser revolution valve, developed by Interventek Subsea Engineering. The valve was developed to address the limitations of conventional ball valves which use the ball to both cut and seal. During shearing, damage may occur to the ball, which can compromise the sealing ability of the valve. The patented valve bore closure mechanism developed by Interventek separates the cutting and sealing surfaces to increase reliability and well-control safety.
Ahead of prototype manufacture and before product testing was finalised, AS Mosley was assigned to undertake computer modelling and test simulation of the new valve to confirm its structural capacity in high-temperature and high-pressure environments.
Richard Robinson, Technical Consultant at Oyne-based AS Mosley, said: “Our engineers performed analysis on the structural and pressure containing components of the in-riser valve using the ANSYS Workbench FEA software. This allowed us to fully assess the valve in different real-world scenarios. The process took around 6 weeks to complete and the results were very promising. The outcome triggered the manufacturing phase of the new valve, which has been hugely welcomed in the industry. It has now been delivered for its first commercial application in the Gulf of Mexico for well-intervention work. We feel proud to have been a part of the product development phase and wish Interventek continued success with the Revolution Valve. The FEA software played a significant role in the design verification ahead of testing and we would highly recommend other companies with innovations to use FEA early in the design process, ahead of prototype manufacture and testing.”
AS Mosley is an engineering consultancy specialising in well integrity. The company employs 16 staff and specialises in complex and challenging analysis in the oil and gas industry including global riser analysis, wellhead fatigue and local FEA.
For more information on finite element analysis, contact AS Mosley at www.asmosley.com
