<p style="text-align: justify">&nbsp; In the process of ocean gas transportation, the rupture of submarine pipelines due to various problems will cause large-scale ocean pollution and bring extremely harsh harm to the marine environment. Most of the existing detection methods follow the land pipeline leakage method, which has low sensitivity and poor applicability due to the complexity of the marine environment. When the submarine gas pipeline leaks, the gas escapes in the form of bubbles, accompanied by an acoustic signal that can reflect its own size. Information such as the size of the bubble can be inverted from the collected acoustic signals. In this paper, the bubble dynamics model of pipeline leakage based on the finite element simulation is established to quantify the relationship between bubble volume and acoustic signal characteristic frequency under different leakage conditions. A subsea pipeline leakage gas flow measurement algorithm is proposed, which can be used for constant and variable speed leakage. The signal-to-noise ratio and measurement stability of the collected seabed signals can be improved through complementary ensemble empirical mode decomposition and adaptive frequency matching. The normalized energy window is used to determine the time period of each leaked bubble to ensure the accuracy of the frequency identification. The indoor 1.4×1.4×1.2 m rectangular transparent tempered glass water tank was used as an experimental platform to measure the gas flow rate under different leakage conditions. The results show that the measurement error of this method is controlled within 1% under the constant flow condition of 0-100mL/min, and 50mL of variable-speed leakage gas can be measured within 5 seconds. This paper will provide a new detection method for marine micro gas leaks and provide a strong guarantee for the development of marine energy industry.</p>

Leak Detection and Leakage Assessment of Submarine Pipelines Based on Passive Acoustics

Paper Proceedings: https://asmedigitalcollection.asme.org/qnde/QNDE2021/volume/85529

ASME 2021 48th Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE2021)

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.