摘要 |
<p>A METHOD FOR DETERMINATION OF INTERNAL PIPELINE OR TUBING CORROSION A method for determining the variations of the internal condition of a pipeline or tubing (1), by propelling a pig (2), which is sealed against the pipeline or tubing wall, through the pipeline by means of a constant flowing driving fluid comprising the steps of continuously measuring (5) and recording (6) the pressure of the said driving fluid or the pressure differential across the pig (2) during pigging of the pipeline or tubing (1) and deriving from the recorded pressure signals a plurality of quantities representative for the pressure variations in selected successive intervals of the pipeline or tubing (1), each interval having a predetermined length, in such a way that the total length of the pipeline or tubing to be inspected is covered, and comparing the values of the quantities thus obtained with reference data of these quantities, and deriving from said comparison information as to the internal diameter variations of the pipeline or tubing (1) being inspected.</p> |