IMPROVED INTERPRETATION OF THE DOWNHOLE CASING INSPECTION LOGS FOR TWO STRINGS OF PIPES.

Abstract

The increasing concern for safety, and more stringent government regulations has placed additional pressure on operators to use two, or even three, strings of pipe as a measure to protect their wells and gas storage against potentially hazardous leaks and damages. The presence of the second or third string of casing makes downhole inspection by electromagnetic methods considerably more difficult not only in terms of data acquisition but also in terms of data interpretation. This occurs because the tool response is strongly influenced by the additional string, especially for the eddy current tools used to measure wall thickness of pipes.