Dynamic monitoring


Ashtead Technology have an extensive array of packaged solutions covering a range of dynamic monitoring applications.

Through their lifecycle dynamic systems and components such as drilling and production risers, umbilicals, flowlines, jumpers, mooring systems and jacket structures have to endure dynamic stress loadings through wave, current and production flow which can induce material fatigue. Carbon steel is well known for its finite fatigue endurance but other materials can also be susceptible.

Whilst numerical models can be developed for specific applications to predict fatigue rate, these are based on theoretical conditions and may not represent real world behaviour. Physical measurement of structures and components will reveal actual vibration modes and amplitudes, and this data can be used to validate models and to provide real-time information under changeable circumstances.

Working with our strategic partner 4Subsea our in-depth knowledge and experience of dynamic measurement techniques can provide a complete real-time dynamic monitoring and data interpretation service to suit specific needs, providing vital information on actual structure dynamics, protecting and extending asset life.

Integrated solutions


Discover how Ashtead Technology incorporates market-leading technologies and innovative life of field services to help clients deliver complex projects.

Vortex induced vibration (VIV) can occur on deep-water and shallow water steel riser systems and flowlines. With a constant current-induced vibration, depending on amplitude and frequency of vibration, the dynamic stress that results causes stress fatigue cracking. Understanding the motion characteristics of the flowline, riser or structure can be monitored by use of precision accelerometer sensors from which motion characteristics can be extracted.

Working with our strategic partner 4Subsea we have extensive in-house expertise in measurement of dynamic motions and attitude of offshore and subsea structures and experience in providing monitoring solutions and providing real-time information and post-processing of data to extract behavioural information.

Ashtead Technology in collaboration with 4Subsea can also provide full temporary or permanent VIV monitoring services to physically acquire vibration data and extract information using real-time characterisation and post-analysis techniques to allow informed decisions to be made to protect and prolong the life of assets.

Unstable or periodic flow can cause moderate to high levels of stress fatigue on subsea risers, jumpers and connection systems. Slug flow is a more common creator of periodic stress and this more commonly occurs during start-up/shutdown and where production flow is turned down this can cause mechanical damage over time.

With our experience and knowledge in applying dynamic sensing techniques, Ashtead Technology in collaboration with 4Subsea can help quantify the effects of loadings caused by periodic flow instability and to extract information and allow informed decisions to be made, protecting and extending asset life.

Mooring systems are normally subject to dynamic loading driven by wave and wind, which drives periodic and impulse dynamic tension and motion effects through vessel response to these external influences. The result is a combination of cyclic and impulse fatigue stress and abrasion wear on mooring system chain links and connection components.

By understanding the mooring system motions and accelerations in respective axes, these can be translated into chain wear and fatigue information which can be used to assert mooring system integrity and predict chain life.

With our experience and knowledge in applying dynamic sensing techniques, Ashtead Technology in collaboration with 4Subsea can help quantify the effects of loadings caused by periodic flow instability and to extract information and allow informed decisions to be made, protecting and extending asset life.