Integrity assessments for internal or external corrosion damage on an exposed pipeline are only as accurate as the methods which measure the extent of the damage. Inaccuracies in measurement can lead to unnecessary repairs or non-conservative assessments.
This paper describes the development and use of three systems used to reliably and efficiently measure corrosion damage on both internal and external pipe surfaces of exposed in-service pipeline segments. They are based upon the application of laser optics, magnetic flux leakage and ultrasonics. The use of these systems allows for more accurate corrosion damage assessments, thereby reducing the number of unnecessary repairs and cut-outs, and reducing the risk of non-conservative assessments.
The laser-based and ultrasonic systems provide contour maps of corroded areas. Software that incorporates the RSTRENG method is used to assess the significance of the damage from the data.
Examples of the applications of all systems on large-diameter gas and oil pipelines are provided along with a discussion of their impact.