Fracture detection using circumferential offset acoustic paths.

摘要

In the apparatus and method of the invention, acoustic energy is propagated in two slightly differing, or offset, circumferential paths in such a way as to interact with the formation under investigation. The propagating energy is detected and the resulting waveforms are compared using semblance. The waveforms corresponding to the respective paths will be quite similar provided that the length of the paths are equal and that there are no fractures or other similar anomalies between the source and receiver. The waveforms for the respective paths will be quite dissimilar, however, if a fracture or similar anomaly does lie between the source and receiver for the respective paths. The semblance may be displayed in log format.