Three-Dimensional Ultrasonic Reverse-Time Migration Imaging of Submarine Pipeline Nondestructive Testing in Cylindrical Coordinates

Abstract

Submarine pipelines are a safe and energy-efficient mode of gas transport. However, due to the complex manufacturing process and harsh operating environment, submarine pipelines are subject to fatigue cracks under long-term cyclic loading. A comprehensive and high-precision characterization strategy for submarine pipelines can effectively prevent potential safety hazards and have significant economic and social repercussions. As a matter of fact, pipeline defects cannot be reliably detected with current traditional 2D methods. On the other hand, in ultrasonic testing, cylindrical geometry increases the complexity of the 3D wave field in the submarine pipeline space and significantly influences the accuracy of the detection results. In this paper, we put forward a novel method for 3D ultrasonic image testing that is suitable for cylindrical coordinates. In order to accurately simulate the ultrasonic signal received from pipelines, we generalize the 3D staggered-grid finite-difference method from Cartesian coordinates to cylindrical ones and simulate the full wave field in the 3D pipeline space. Then, signal processing is performed on the ultrasound simulation records, and 3D reverse-time migration imaging of submarine pipeline defects can be effectively achieved using the reverse-time migration method and cross-correlation imaging conditions. The results obtained from simulations and real field data show that the proposed method provides high-quality 3D imaging of defects in pipelines, taking into account multiple scattering and mode conversion information at the bottom of the defects.

An Application of 3D Cross-Well Elastic Reverse Time Migration Imaging Based on the Multi-Wave and Multi-Component Technique in Coastal Engineering Exploration

“…The RTM algorithm, with its significant impact on imaging accuracy, relies heavily on the imaging condition [51,52]. Different imaging conditions employed in the imaging process can lead to different imaging results.…”

Research on the 3D Reverse Time Migration Technique for Internal Defects Imaging and Sensor Settings of Pressure Pipelines

“…Cracks, inclusions, thinning, and other defects may occur under long-term cyclic loading, ultimately leading to equipment failings often associated with casualties and significant economic losses [2]. Therefore, conducting a thorough, high-precision inspection of pressure pipelines, coupled with swift and precise detection of diverse defects, has the potential to proactively mitigate safety risks and yield positive economic and societal impacts [3].…”

Experimental Investigation on Near-Field Acoustic Propagation Characteristics of Leakage Detection in Submarine Pipelines

“…Pipelines, central to oil and gas transport, are essential in the development and production of these resources [2]. Over time, as the pipeline operates, leakages can occur due to corrosion, aging, cracks, natural leaks, and other reasons [3]. Such leakages not only affect normal production activities but also cause serious economic losses and environmental degradation [4].…”