A Study Of Key Techniques In Casing Damage Detection Application

Under the background of casing damage detection in oil & gas fields, this paper performs a study of key techniques in this application. At first classical electromagnetic theory and one particular branch of it一TEM and its utilization in production logging are studied to lay down theoretical basis. Then the paper carries forward a major research to functional modules of the TEM logging prototype instrument in order to improve its performance and stability, such as probe structural symmetry, depth measurement accuracy and reliability of uplink communication from the instrument to the ground system.Various relevant influences are studied in casing flaw inspection, including system power, probe parameters, logging speed, tool eccentricity, magnetic noise and ambient temperature both in theoretical sense and practical results, which can be effective criteria of further data revision. A comprehensive calibration scheme of magnetic probes is presented to validate flaw detection capability and to offer reference of flaw type determination, as well as interpretation of response data discussed to prepare for feature extraction and imaging in the following research.Finally testify flaw inspection stability, repeatability and consistency of the TEM logging instrument in a wide range of production wells with a comparison among acquired data, and conclude the paper with detailed specification on its detecting performance.