Aquaterra Energy has launched a unique Riser Monitoring System (RMS) which the company believes will revolutionise the integrity management process and deliver superior reliability and accuracy of data acquisition for the offshore oil and gas industry. The RMS design utilises a combination of direct riser strain measurement, subsea data logging and riser analysis processing algorithms to generate accurate, real time operational guidance on optimising drilling and workover operations in water depths of up to 100m.

Eric Doyle, Regional Director – Europe at Aquaterra Energy, said: “Heightened sensitivity around health and safety and project critical risks associated with riser fatigue have resulted in an urgent need for innovation in riser integrity management, driving our innovation in this field.  This new RMS will assist our clients with precision planning of maintenance activities and deliver real potential for safe asset life extension.

“It combines rapid data processing and high fidelity output with proven analysis expertise, to offer our clients a leading edge solution to integrity management.  The solution is delivered through the use of a bespoke, standard length, riser joint, which replaces a standard riser joint in the stack up, with pre-installed data acquisition and logging hardware, resulting in virtually zero impact on operations.

“The integration, complexity and practicality of the data handling in the RMS is unique to Aquaterra Energy and the accumulated strain data can either be stored locally or transmitted back to surface for live evaluation.”

A full scale prototype of the RMS unit was developed by Aquaterra Energy in the structures laboratory of the University Engineering Department at the University of Cambridge and, in partnership with the University, all elements of the system have been tested and verified to ensure maximum reliability.

Dr Chris Burgoyne, Head of Structures at the University of Cambridge, said: “This is an interesting use of sensing technology for the offshore oil and gas industry and the structures group is happy to be working with Aquaterra Energy on such an innovative application.”

Aquaterra Energy’s RMS uses pre-processed computationally intensive data which ensures that analysis, including the usually time intensive component fatigue utilisation determination, is rapid and that a full range of potential input conditions, tabulated in a multi-dimensional matrix, is provided.  Measurement, evaluation and specification of key variables, specific to each strain cycle contained within the measured data, allow an accurate representation of the critical boundary conditions to be produced.  This subsequently enables comparison with the pre-processed data, as well as directional fatigue assessment for each constituent component along the full riser length.

The system’s four strain gauge devices facilitate superior reliability and accuracy to alternative data acquisition methods. The gauges are protected from accidental damage by a casing which also contains the logging hardware, in combination with modular battery pack expansion slots, which facilitate up to five years logging time.

Doyle concluded: “Unlike conventional methods, abutment to the riser is by a specially developed subsea epoxy resin, achieving one of the products key objectives – measuring the riser and not a clamp.  This improves riser stain measurement accuracy whilst eliminating the need for welding which causes damaging fatigue hot spots.”

The development of this RMS is illustrative of Aquaterra Energy’s approach to delivering innovative outcomes to offshore challenges.  The expertise and attention to even the smallest detail that our team employs in delivering such solutions, is intrinsic in all our riser engineering work, and highly valued by our clients.”

The RMS is fully compliant with DNV-RP-F206 and ISO 13628-7 specifications and certified to ATEX Ex ib IIB T4.