Acoustic Sensing-Based Detection Methodology for Downhole Fallen Objects in Oil and Gas Wells

In oil and gas exploration and production, downhole fallen objects in wells represent a significant operational challenge that demands immediate attention. Timely detection of such fallen objects is crucial to ensuring the safe and efficient operation of oil wells. This study adopts a comprehensive approach that integrates finite element simulations with experimental validation to investigate the potential application of ultrasonic imaging technology for downhole fallen objects detection. The study first employed finite element simulations to model the impact of fallen objects on acoustic wave propagation, with a focus on examining the correlations between the reflected signal and the fallen objects’ spatial position, size, and the probe’s excitation frequency. Based on the simulation results, an innovative ultrasonic imaging method for detecting fallen objects was proposed. Building upon the insights gained from numerical simulations, a dedicated experimental platform was developed to validate the proposed approach. Both simulations and experiments successfully generated two-dimensional overhead images of the fallen objects, facilitating the identification and characterization of their properties. The findings underscore the feasibility and effectiveness of ultrasonic imaging technology for detecting downhole fallen objects in the water and mud, but are theoretically extensible to oil/gas via simulation. This research not only demonstrates the practical application of this technique but also offers valuable insights for advancing future studies in ultrasonic fallen object detection.