Patent Document ID: 20090229362
Application ID: 12379944
Patent Status: 0

Claim One:
1. A method for non-destructive inspection of defects in a surface of a pipeline or storage tank for hydrocarbon transport or storage, including the steps of: a) carrying out a first way of non-destructive inspection of a first part of the surface by moving a first inspection tool along the first part of the surface for determining a first defect pattern that includes dimensions and positions of defects in the first part of the surface; b) carrying out a second way of non-destructive inspection of a second part of the surface by moving a second inspection tool along the second part of the surface for determining a second defect pattern that includes dimensions and positions of defects in the second part of the surface, wherein the total area of the second part of the surface is smaller than the total area of the first part of the surface and the second part of the surface overlaps with the first part of the surface, and wherein a systematic error of the second way of non-destructive inspection is smaller than a systematic error of the first way of non-destructive inspection; c) identifying at least one defect of the first defect pattern and at least one defect of the second defect pattern which represent one and the same defect; d) comparing the dimensions and optionally also the positions of the identified defects in step c) which represent one and the same defect so as to obtain a difference in dimensions and optionally also in the positions measured with the first way of non-destructive inspection and the second way of non-destructive inspection respectively; e) repeating steps c) and d) so as to obtain a plurality of differences and obtaining at least one parameter representing said differences; and f) correcting the dimensions and optionally also the positions of defects of the first defect pattern by using the at least one parameter obtained in step e).