— Extraordinary for erosion monitoring in complex structures

Throughout his 40 years of working with instrumentation in the Oil & Gas Industry, John Hird has acquired an almost unprecedented expertise and insight into instrumentation for subsea systems. We asked John what he considers important when choosing technology for monitoring pipeline erosion – and his opinion on what makes Sensorlink’s technology unique.

John Hird is a well-known name in the industry. He spent 15 years with Chevron, initially as a Subsea Controls Team Leader & Technical Authority in their European business unit and latterly as a Senior Subsea Controls Advisor to the global corporation. Prior to his time at Chevron, John worked on the designs of a wide range of drilling and production control systems and instruments. Today, few people can match his insight and knowledge of subsea instrumentation. Principal engineer Hird now works as a brain-for-hire through his own consultancy firm, Orra Loon Consultants Ltd.

50 years of service life
Some years ago, Hird was tasked with choosing the monitoring technology for a truly unique erosion monitoring project.

— We worked on an expansion of a subsea field and needed highly accurate measurements. We also needed instruments that would function flawlessly in harsh subsea conditions over the course of 50 years – while remaining completely untouched after the initial installation. A service life of 50 years is remarkable; a world first for any comparable instrumentation, says Hird.

Hird and his colleagues considered a wide range of suppliers, before landing on Sensorlink.

— For this application Sensorlink’s solution offered better reliability and redundancy than the other suppliers, and without a doubt the most accurate measurement around a complex pipe geometry.

A matrix of sensors
However, in the end, none if these features were the decisive factor. For Hird, what tipped the scale in favor of Sensorlink was the unique utilization of ultrasonic technology.

— The hardware itself is not revolutionary, nor is the instrumentation. However, Sensorlink’s ability to create a “blanket” of sensors covering a large area – even of complex structures – is unprecedented. 

In the subsea project, Hird’s colleagues had identified a bend within the subsea Christmas tree system where they wanted to precisely monitor the erosion rates over time.

— Other technologies often work quite well on straight lines of material, but none handle bends and other complex geometries like Sensorlink’s technology. It is extraordinary for monitoring complex structures, says Hird. He also highlights the fact that Sensorlink can deliver accurate measurements through multiple layers of differing materials, for example a combination of carbon and corrosion resistant alloy cladding.

— In this specific project we applied 256 sensors – each measuring the wall thickness directly below the sensor, delivering non-intrusive measurements on a 2,8-centimeter-thick wall, with an accuracy down to 20 microns. The sensors are very closely situated and arranged in a matrix. Single point measurements like this, however, is nothing new, smiles Hird.

Accurate monitoring of large areas
The real advantage lies in how Sensorlink interprets these single point measurements as a whole.

— The fact that they can gather this matrix of information – with so many points of data, from a complex shape such as an elbow or a joint – and come up with highly precise erosion and corrosion rates and predictions, is very valuable for any integrity engineer. Treating the whole pipe as a single item, based on information from hundreds of sensors require both a profound understanding and exceptional software.

Hird’s recommendation
Hird would recommend Sensorlink to other’s who want to accurately measure erosion and or corrosion rates, particularly in complex geometry. At the aforementioned subsea project Hird has particularly appreciated Sensorlink’s proactive attitude towards remotely collecting and analyzing data, so the delivery can be further optimized remotely.

— The company is easily as strong as their technology – with knowledgeable experts constantly fine tuning their delivery in accordance with the needs of the clients. This plays directly into Sensorlink’s greatest strength; using their knowledge and experience to create what the customer actually needs. Many companies develop smart solutions – but they are not always focused on the operator’s actual needs. This means that the clients often work with instrumentation that doesn’t quite give them what they want and expect.

— Sensorlink listened to us from concept design through to installation on the x-trees, making rapid changes to ensure they delivered what we wanted. This level of supplier openness and flexibility is rare, but its importance shouldn’t be underestimated in achieving our mutual goals.