Patent ID: 6366859
Filing Date: 2002-04-02
Classification: G01V

Abstract:
Method of detecting breaks in logging signals relating to a region of a medium and consisting of logs of different kinds recorded for the said region as a function of depth, of the type consisting in:selecting a portion from each of the said logs in such a way that all the selected portions have a same depth interval in common, one of the selected portions being regarded as reference portion, determining a sequence of spatial analysis frequencies, selecting a parent wavelet function and constructing, from the said parent function, a family of wavelet analysis functions dependent on spatial frequency and on depth, calculating a wavelet transform of the selected portion of each log and for each spatial analysis frequency, choosing a characteristic quantity of the wavelet transform and in using this quantity as a representation of the wavelet transform, the said method being characterized in that it furthermore consists in: calculating, for each portion of log selected and for each depth datum, the absolute value of the mean gradient of the characteristic quantity of the wavelet transform for the various spatial analysis frequencies, selecting, for each portion of log processed, the peaks of the absolute value of the mean gradient of the characteristic quantity, each peak corresponding to a break, determining the corresponding breaks over the reference log portion, defining an analysis window centred on each break of the reference log portion, and selecting the breaks of the other log portions which lie in the analysis window.