Microleakage localization method for subsea production manifold based on transient pressure wave

Subsea production manifold is the center of collection and distribution of subsea oil and gas production. Microleakage will occur on long-term service manifold, if not timely intervention, will evolve into environmental pollution and huge economic losses. In this paper, a microleakage localization method for subsea production manifold is proposed. Through cross-validation of multi-scale data and model information, the complex aliasing strong noise modes can be reasonably filtered and effectively separated. The leakage pipeline identification model based on local linear fitting is established. A microleakage localization based on the boundary-enhanced dynamic time warping matrix is established to analyze the pressure time series of the microleakage. The arrival time difference is obtained by combining the distance of the greatest similarity with the signal sampling frequency. In combination with the dynamic pressure wave propagation velocity in the manifold, the microleakage localization is realized. The effectiveness and accuracy of the method are verified by the microleakage simulation experiment of the prototype of the subsea production manifold principle. The average identification accuracy of the proposed microleakage localization method is 90.48 %, the average localization accuracy is 98.94 %, and the average localization error is 12.83 cm. The changing law of localization error at different pressure is also analyzed.