AS Mosley provides a range of additional engineering services as part of a larger project or as an individual assessment. As with all other areas of analysis we can provide assistance from the FEED stage to the final detailed design. We are also happy to provide third party review where we have necessary experience.
Engineering Critical Assessment (ECA)
AS Mosley performs Engineering Critical Assessments to estimate the life expectancy of a weld or connection for a given load spectrum. This can be carried out in combination with finite element analysis in order to properly understand the stress and strain distribution in the region of a defect. A laboratory test and inspection is carried out to establish material properties in preparation for determining crack growth rates in relation to a critical defect size using fracture mechanics software. The ECA can be used to determine detailed inspection requirements for optimum fatigue life.
Riser Recoil and Dynamic Tension
By creating a detailed global model of a marine riser tensioner system and anti recoil flow control it is possible to determine the dynamic tension in the riser in relation to vessel heave motion. AS Mosley can perform dynamic tension assessment for conventional wire tensioners or Direct Acting Tensioner (DAT) cylinders.
The global model of the tensioner system can be extended to investigate the recoil response of the tensioner system during emergency disconnect at the LMRP. AS Mosley use anti recoil analysis to optimise the tension of a riser system in order to avoid critical events like riser compression, collapse of the telescopic joint, slack tensioner lines and clashing of the LMRP with the BOP.
Snag Load Assessment
Snag load assessments are sometimes required as part of a wellhead and conductor analysis. The snag load - generally from fishing gear - can be applied to any part of the subsea structure.
Impact load assessments based on dropped objects or from fishing trawler board strikes can be performed by AS Mosley. The impact load assessment is carried out to determine the loads transferred to the tree and wellhead. Furthermore, analysis can be performed to optimise the protective structure.