Using acoustic logging signals of segmented bond tool to detect the cementing quality

Good cement bonding quality is significant for an oil well to provide zonal isolation and to ensure layered exploitation. Segmented bond tool (SBT) is efficient to detect the bonding conditions between casing and cement. In order to learn more about the physical basis of the SBT equipment, the influence of debonding area on head wave is investigated. With the debonding area increasing in size from 0° to 360°, the average attenuation coefficient increases. However, the SBT can hardly be used to evaluate the bonding equality between cement and rock formation. In order to make a further usage of the tool in detecting the bonding conditions on the interface between the cement and the formation, the full waveforms are received and analyzed, propagation of guided waves both in well-bonded and debonded cased wells with channels at the cement-rock interface are studied and compared. It is realized that certain flexural mode is sensitive to the debonding between cement and rock and helps to detect the cement bond quality.