A well collar counting methodology is provided comprising first obtainingacoustic pulse data from a well and then digitizing and storing the amplitude-versus-timesignal for subsequent processing. The raw signal is processed by applying a WaveletTransform thereto for producing multiple resolutions of the signal, preferably four, at leastone of which has a transformed signal resolution sufficient to distinguish reflectionsemanating from collars, and one of the coarser resolutions having a transformed signalresolution sufficient to distinguish reflections emanating from the fluid surface as kicks.The fluid surface kick and repeat kicks are determined by performing multi-resolutionalanalysis of each maximum, at the coarser resolution, as synchronized against thesuccessively finer resolutions and compared as being significant with respect to adjacentmaximums. Tubing collars are then counted at a finer resolution, as being reflectionmaximums counted in the interval between the wellhead and the kick, irrespective oftubing joint length or collar frequency. Direct collar counting, interpolation andextrapolation of collars is performed.
展开▼
