Coiled tubing (CT) is used extensively in oil field applications where it can incur surface defects and imperfections. Fatigue cracks can nucleate prematurely from the surface flaws and reduce fatigue lives significantly. The influence of defects on fatigue life can only be assessed if accurate measurements of the defect geometry are available. Current CT inspection technology is based on magnetic flux leakage (MFL) which is useful in detecting flaws. But, MFL is incapable of quantifying defect geometry information. On the other hand, laser scanning inspection systems can provide direct measurements of the physical characteristics of surface flaws. This technology produces a set of 3D data points that represent a complete surface map of a flaw. Laser scan data have been successfully curve fit using a proven Taubin algebraic fit. With this basis, algorithms for determining critical defect parameters namely, defect depth, width, length, and projected cross-sectional area were developed. The results are within the specified accuracy of the laser scanner. The notch root radius can be estimated by curve fitting the flaw geometry at the root of the notch. The success of obtaining notch root radius depends on density of laser-scan data and absence of shadow effects. A laser scan system with lower incidence of shadow effects will further improve the effectiveness of a laser scanner inspection tool. This technology has tremendous potential as a general purpose inspection tool for oil field piping systems.

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