Acoustic surface imaging using time of flight

Abstract

A system, device and method for imaging, measuring and identifying surface features in a tubular, such as a casing, wellbore, or pipe. The device comprises an ultrasound transducer for sonifying an area of the surface of the tubular, with a pulse intercepting axial locations of the sonified area at different times. Reflected signals are processed using their time of flight to interpret the reflected signals as axial locations of features on the surface of the tubular. Multiple sonified areas are partially overlapped in the axial direction to capture features redundantly. Reflections from the multiple areas are combined to remove noise and strengthen reflections from real features. A geometric model of the surface of the tubular is rendered and displayed. Capturing larger areas per frame increases the logging rate and oversampling improves the resolution and signal to noise ratio.