Acoustic transducer and method of manufacturing

A first metal layer 23 is deposited on a first side of a piezoelectric composite 22 to form a common electrode, a second metal layer 25 is provided over the opposite side and a thicker third metal layer 26 may be provided over the second metal layer 25. Portions of the second metal layer are removed to create a plurality of individual electrodes (fig 4B). The individual electrodes extend 24 beyond the piezoelectric composite 22 in the elevation direction to create an improved attachment contact point for electrode leads. The metal layers may be provided by lithography, a wireframe or a foil sheet. Several array shapes are discussed (figs 6, 7, 10). The transducer array is intended for downhole use (figs 10, 11).

Ultrasonic inspection of complex surfaces

A device and method used to log images of tubular pipeline with ultrasound transducers. The method comprises; transmitting a wave towards the tubular using a phased array ultrasound transducer; storing received reflection signals off the tubular; performing beamforming on the reflection signals to locate an inner surface of the tubular; defining an inner surface boundary model using the located inner surface; tracing rays from the transducer through locations within the tubular and back to the transducer, using the model and incorporating localised reflections; calculating time-of-flight for the rays using a speed of sound of a coupling fluid and the tubular; and using the time-of-flight, sampling and summing the stored reflection signals to calculate image values for pixels representing the tubular; and assembling the pixels to visualise the tubular.

Ultrasonic inspection of complex surfaces