NDT Applied to the Detection of Defects in Oil and Gas Pipes: A Simulation-Based Study

Abstract

This research investigates the application of microwave nondestructive testing (NDT) to oil and gas pipe wall reductions (PWR) in manufacturing that are less than full-circumferential in extent. Pipes were modeled using Computer Simulation Technology (CST) simulation software, CST Microwave Studio holding pipe length, wall thickness, depth of PWR and configuration constant. The study looks at 32 models in order to determine sweeping frequency limitations for full-circumferential, half-circumferential, three-quarter-circumferential and quarter-circumferential extents of PWR with 8 widths ranging from 6.35mm to 50.8mm. The limitations were determined to be between the extremes. The 6.35mm width did not cause a resonance peak even with a full-circumferential PWR. The 50.8mm width produced a detectible resonance peak, but it is within the range established by the six middle widths.

Design of a simple side-incident TE11 mode microwave probe for nondestructive pipe inspection

“…In particular, a back propagation neural network was trained in that study to quantitatively evaluate the depth and length of a wall thinning defect using the extracted resonant frequencies of TM 01 microwave signals and showed good performance. Previous studies have proven the feasibility of this method in detecting wall thinning [15][16][17], cracks [18,19], corrosion under insulation [20], and leakage in buried pipes [21] and biofouling [22,23]. In particular, microwaves in the TM 01 mode with the axial surface current density and in TE 01 mode with the circumferential surface current density on the pipe wall showed high sensitivity to circumferential [18] and axial cracks (slits) [19] with the width about 1 mm, respectively.…”

Non-Destructive Measurement and Evaluation of Surface Cracks Using Ultrasonic Rayleigh Waves – A Review

“…This defects can occur on the surface or on the subsurface of the materials. [17] Porosity occurs from the gas bubbles trapped in the metal filler during the solidification process. Porosity can often be avoided if the work pieces are completely clean before any weldinf process and the welding current are kept belo excessive level.…”

“…Porosity can often be avoided if the work pieces are completely clean before any weldinf process and the welding current are kept belo excessive level. [17] Crack may be develop during the weld metal solidifies and shrink. The weld will become weaker because the weld metal is no longer continuous shown in figure 13.…”

“…The weld will become weaker because the weld metal is no longer continuous shown in figure 13. [17] The defects occurs when the welding bead fails to adhere, fuse with the base metal, leaving a weak joint shown in figure 14. This can happen because of contaminated surface.…”

“…This can happen because of contaminated surface. [17] Each type of irregular shape has their own cause, but they are all result in stress sensitive joints that are subject to failure earlier.…”