Simulation of porous leakage sound field under the liquid surface of gas well annulus

Oil casing leakage in offshore gas wells has always been a key concern, and the state of leakage points located under the liquid surface of the annulus is even more difficult to judge. In order to study the acoustic characteristics of single and multiple leaks under the liquid surface of the annulus, this paper establishes a physical model of oil casing leakage with multiple leakage holes, and combines STAR-CCM and other simulation software to simulate the gas leakage under the liquid surface of the annulus in terms of flow field and acoustic field, and obtains different numbers of leakage holes in the flow field phase cloud diagram and acoustic field acoustic pressure cloud diagram and curve. The results show that the sound source of the leakage under the liquid surface is mainly the quadrupole source, and the acoustic wave energy is mainly distributed in the interval of 50∼100Hz. The results provide a theoretical basis for the acoustic wave method to detect the leakage state.