PR-398-113719-R01 Technologies for Monitoring Erosion Corrosion and Direct Inspection of Subsea Assets

This Final Report prepared by ESR Technology Ltd., provides the results of a study on subsea pipeline erosion and corrosion monitoring. The report is therefore split into two parts. The first part deals with monitoring erosion and corrosion, subsea; and the second part is on direct inspection techniques to monitor wall thickness loss.

Generally, Subsea equipment is significantly more difficult to inspect than topside or land-based equipment and the study recognizes that many challenges and technology gaps remain. Sand, produced from oil & gas wells, can cause erosion & erosion/corrosion of subsea production systems and presents a number of threats to the safe reliable and economic operation of a facility. Sand control systems (e.g. sand screens) are used to prevent or limit sand production and therefore prevent erosion. In some developments, however, downhole sand control is not feasible and sand production may occur leading to erosion of the flowlines, pipes and equipment.

Since erosion is strongly linked to flow velocity at bend points, erosion damage is principally a concern of equipment downstream of the wellhead (where the operating pressure is low) rather than being associated with damage to the well tubing (where operating pressure is relatively high but the flow path is predominantly straight).

The goal of this research project is to screen current and potential techniques that provide a direct measure of loss of pipe wall thickness, rather than indirect measurement (e.g. erosion and corrosion probes, acoustic sand and electric field corrosion monitors). Such techniques should also be capable of being embarked on AUV, snake like robots, mini ROV etc.