By Kevin Clarke, Chief Revenue Officer, Permasense

CONTINUOUS integrity monitoring systems combine permanently-installed, ultrasonic sensor technology with wireless communication to deliver wall thickness data of the highest integrity to the corrosion engineer’s desk.

The Permasense-designed systems enable direct, accurate and frequent measurement of pipe wall thickness to identify corrosion or erosion trends in a timeframe and with an accuracy not possible with manual inspection methods.

The system is being used to monitor corrosion and erosion activity with unparalleled accuracy and response time, delivering data that enables decisions to be made to avert disasters or operate facilities more profitably.

Understanding corrosion as it happens

Steel pipework and vessels are always at risk of corrosion or erosion to a certain degree, depending on the metallurgy, the process fluid aggressiveness and the process conditions.

Unless managed carefully, there is a potential risk of failure with a possible consequential impact on the environment and/or personnel and plant safety, apart from the financial costs of equipment repairs and the commercial impact of unplanned operational interruption or reputational damage.

The drivers of corrosion and erosion – process conditions, feedstock constituents and abrasive solids – and the chemical inhibitors to hold corrosion rates in check are familiar to the industry.

Today’s situation of operating ageing plant, greater fluid corrosiveness and erosiveness, tighter HSSE regulations, the environmental and reputational costs of a leakage and the growing shortage of skilled inspection staff are adding to the challenges faced by traditional plant integrity monitoring processes.

Permasense’s permanently installed integrity monitoring system represents a significant step forward in providing asset and integrity managers with an up-to-date picture of how the infrastructure is coping with the demands placed upon it.

The data enables more effective use of mitigation technologies such as corrosion inhibitors and can also enable more profitable operation through increased production rates or better-informed enhanced feedstock selection.

Online Ultrasonic wall thickness measurements

At the core of all Permasense systems is an ultrasonic sensor mounted on stainless steel waveguides.

The waveguides isolate the sensor electronics from potentially extreme temperatures and guide the ultrasonic signal to the pipe wall and back.

Permasense sensors are powered by long-life batteries, and transmit their data using wireless communication.

As a result, cabling to monitoring locations is not required, which substantially reduces the cost of installation, and enables rapid deployment in difficult to access and remote areas.

Wall thickness data can be retrieved from sensors that are operating in extreme temperatures and environments and in the remotest of locations.

Automatic classification of data by corrosion rate allows quick and easy determination of where corrosion or erosion activity is occurring across the monitoring locations.

Insights to better control corrosion

Direct, accurate and sufficiently frequent measurement of pipework thickness to accurately identify trends is rarely practically feasible with manual inspection methods when coupled with the challenges of accessibility and avoidance of safety risks to personnel.

Permanently installed sensor systems, on the other hand, deliver continuous data of high quality.

Installed on pipes and vessels operating at up to 600°C sensors have been certified as intrinsically safe for use in the most hazardous of environments, and proven in operation over a number of years in refinery environments, onshore and offshore upstream facilities.

Typical investment decisions are justified by safety and operational risk mitigation factors – assuring plant integrity, improving equipment availability, accessibility of measurement points from an inspector safety point of view, or changing the role of limited resources (like qualified inspectors) from making measurements to analysing the causes and mitigation of corrosion.

Once installed, these systems are highlighting where and when corrosion is taking place. This information is proving particularly valuable in informing the production planning and operations decision making processes, to drive the plant towards improved profitability.

Summary

Operators using permanently installed continuous corrosion monitoring systems have a more accurate and timely understanding of the corrosion and erosion rates occurring within their facility.

Permasense now has over 6,000 sensors deployed in over 50 upstream and downstream facilities across five continents.

The data delivered from these systems has helped avert unplanned shutdowns and/or enabled more profitable operation of these facilities.