Buried Corrosion Monitor

Background

ClampOn CEM (Corrosion-Erosion Monitor) was selected for integrity monitoring of buried pipes at a location in the Gulf region. The instrument was installed underground with cabling to a cabinet with solar power and radio telemetry. The ClampOn CEM was chosen due to its large 360° coverage area, resolution, performance, and cost.

Challenge

Site-specific challenges included underground installation, solar power, and system integration over a radio link. The radio telemetry and solar power solutions were contracted locally to ensure local service and maintenance. It was important for the project to have local knowledge for quick mobilization and understanding of the system, something that is too often forgotten in projects where equipment is imported.

Solution

The telemetry solution offered a transparent link, minimizing the equipment in the field. This setup avoided the need for a computer or automation controller on the solar-powered field side, maximizing reliability and facilitating remote support from ClampOn. The system uses two-way TCP-IP Modbus communication from the instrument, via radio link, to servers running ClampOn Server software. Processed data are output to the client control system over Modbus or OPC DA. ClampOn Client software can be used to interface with the servers from an operator station or remotely. In this case all data are processed and maintained within the client’s system.

The dry-contact EMAT transducers of the Topside CEM are mounted on coating with thickness up to 1 mm. For pipes with thicker coating, the coating was milled to 1 mm in the monitored areas. To protect the transducers from environmental factors, a custom fiberglass composite enclosure was used, sealed with a viscoelastic compound and equipped with a draining solution. Cabling is brought to the surface via a flexible metal conduit into the CEM Head unit.

Result

Local selection of radio communication, solar panels, and battery systems ensured compatibility and ease of maintenance. The system was configured for six measurements per day, with the flexibility to adjust this schedule via the CEM Server. This setup maximized reliability and made remote support from ClampOn easier, if requested.