Method for flushing seabed oil and gas pipeline with complex loop

The invention discloses a method for flushing a seabed oil and gas pipeline with a complex loop, and relates to the technical field of ocean engineering, and the method comprises the following steps: S1, winding nano-plastic macromolecules in a damaged area of the pipeline, and installing a temporary plugging pipe clamp; s2, by arranging a Christmas tree and controlling a switch valve of the Christmas tree, all pipelines form a cleaning loop; s3, preparing cleaning medicine liquid, and performing pressure test detection on a medicine injection point and a pipeline; s4, cleaning the whole cleaning loop by using cleaning liquid medicine; and S5, discharging the cleaned waste liquid after the waste liquid is treated to be qualified. The oil and gas pipeline cleaning quality and efficiency can be improved, the cleaning cost is reduced, the environment is improved, and huge economic benefits and social benefits are created by combining oil field enterprises. 本发明公开了一种复杂回路的海底油气管道冲洗方法，涉及海洋工程技术领域，包括以下步骤：S1：在管道破损区域缠绕纳塑