... Abstract In an oilfield well, when the annulus contents behind the casing are evaluated using ultrasonic measurements, the properties of the borehole mud, such as acoustic impedance and fluid velocity, are critical input for the accurate determination of acoustic impedance of annulus material...

... ultrasonic measurements and flexural attenuation measurements and imaging the annulus through these tools to determine actual casing centralization. The log showed a significant improvement especially across the horizontal reservoir sections. The use of these techniques has improved cement quality...

.... In practice, very often, this is untenable – due to the scarcity of shale plugs, experimental challenges, cost consideration and other factors. As alternate, ultrasonic measurements are only performed along the longitudinal axis of the sample, where the apparent dynamic properties are determined using...

... in cement quality from one part of the borehole to another. Annulus imaging is used to evaluate the annulus material. Petrophysical data is used to determine if the formation rock and fluid properties contributed to the quality of the cement behind casing. The principles of ultrasonic measurements...