Characterization Of Well Seals Using An Ultrasonic Method

A downhole ultrasonic method was modified and used to test water well seals. The<br>method analyzes reflections of ultrasonic waves off interfaces to determine the presence of<br>different materials between the casing and formation. The method of waveform analysis was<br>modified for thicker well casings. Indices for characterizing waveforms were compared, and<br>delineation between water and bentonite grout was improved. Laboratory tests using sand as an<br>annular material also led to changes in the method of interpretation. Test results from two water<br>wells are presented. Bentonite grout and sand were detected in the armulus of both wells.