The UCI ultrasonic casing imager measures pits and other anomalies to diameters as small as 0.3 in on the inside and outside surfaces to pinpoint casing damage and corrosion. Absolute measurements are provided for identifying and measuring the depth of corrosion and other casing anomalies without having to reference a base log. An additional output is a qualitative image of the casing condition.
Evolved from the proven USI ultrasonic imager, the UCI ultrasonic casing imager provides high-azimuthal-resolution images as part of making a detailed examination of both the inner and outer surfaces of casing ranging in size from 4 1/2 to 13 3/8 in.
The 2-MHz rotating ultrasonic transducer makes 180 highly focused measurements during each revolution of the sensor. Signal arrivals collected through improved echo detection are analyzed to provide the casing thickness and image of the surface condition. Even small defects on both the internal and external casing surfaces are quantified. An improved centralization system ensures proper positioning regardless of well deviation, and any eccentering effects are reduced through wellsite signal correction.
Although excellent resolution is delivered by the very high transducer frequency of 2 MHz, the signal is attenuated by the borehole fluid. For best results, UCI imager logging should be in brine, oil, or very light muds.