ULTRASONIC CASING AND CEMENT EVALUATION METHOD USING A RAY TRACING MODEL

摘要

Systems, methods, and software for determining impedance of a casing-cement bond are described. In some aspects, the bond impedance is determined based on results of comparing a measured waveform and a model waveform. The model waveform corresponds to an estimated impedance of the bond and corresponds to a ray tracing of an acoustic signal that accounts for a radiation pattern of the acoustic transmitter and a curvature of the well casing. The measured waveform and the model waveform are generated based on operating an acoustic transmitter and an acoustic receiver within a wellbore comprising the well casing.

主权项

1. A method comprising:
accessing a measured waveform associated with an acoustic signal returned via a well casing based on operating an acoustic transmitter and an acoustic receiver within a wellbore comprising the well casing; comparing the measured waveform to a model waveform, wherein the model waveform corresponds to an estimated impedance of a medium surrounding an exterior portion of the well casing, and the model waveform corresponds to a ray tracing of the acoustic signal that accounts for a radiation pattern of the acoustic transmitter and a curvature of the well casing; and determining, by operation of data processing apparatus, an impedance of the medium surrounding the exterior portion of the well casing based on results of comparing the measured waveform to the model waveform.