Mechanical Analysis And Plugging Removal Technology For Oil And Sludge Columns In Shallow Sea

Offshore oil and gas gathering and transportation is mainly carried out by submarine pipelines.China's offshore pipeline industry started relatively late,but it has developed rapidly in recent years.The oil and gas resources of most offshore oil fields in our country are transported to the central platform,processing ship or shore terminal through the sea low pipeline,and then into the downstream enterprises or out of sale.The biggest problem offshore pipelines face today is that the blockage and leakage of sea pipes.In the process of long-distance oil and gas pipeline transportation,there will be pipe plugging,the accident of sea pipe plugging and the safety accidents caused by the improper plugging process,so it is necessary to study the plugging process of the marine oil and gas pipeline.At present,the research of seabed pipeline plugging process is mainly focused on the formation of hydrates on the inner wall of the pipeline and the cleaning of pipe wall oil sludge,the review of the plugging process,the process of plugging,the characteristics of various plugging removal processes and the application status in the engineering practice are not often mature.The removal of hydrate in marine pipelines is usually cleaned up by periodic pigging.However,there are few studies on the blockage caused by the accumulation of excess sludge in the pipe and the accumulation of mud columns in the sea pipe or in the sea pipe,and the related literature is also few.In this paper,through the research and mechanical analysis of the seabed pipeline plugging process,the problems of the sea pipe plugging are studied,and the basic research ideas and main solutions are put forward to provide the theoretical basis and practical reference for the plugging and plugging work of the submarine pipeline in the future.Through the research of pipeline blockage detection and location technology,the advanced inspection methods at home and abroad are introduced,so as to determine the location of pipeline blockage;the oil injection plugging method and hydraulic transient method are studied emphatically,and the hydraulic transient technology is also studied and tested,its practicality and accuracy are verified.Through the mechanical research on the plugging of the oil mud column in the pipeline,the mathematical model of the stress of the oil sludge plugging column is established,and the numerical simulation is carried out by the finite element analysis software ABAQUS.After the analysis,the load and displacement curves of the oil sludge columns with different lengths in the same pipediameter are obtained under the action of each driving force.Extract data,draw load and displacement curves,and summarize the critical pressure diagram of oil sludge column loosening,so as to provide theoretical guidance for oil sludge column plugging removal.The blockage of marine pipelines is mainly caused by three major causes is that hydrates,wax deposits and oil and gas wells.In view of their respective causes and characteristics,different plugging techniques and methods are introduced.It also introduces several cases of offshore pipeline plugging removal,and reviews the technology of sand removal on the ground.Finally,according to the comprehensive analysis of plugging and plugging technology of sea pipe plugging in offshore oil field,the characteristics,applicable conditions and application status in engineering practice of various plugging removal processes are analyzed.Aiming at the problems existing in various plugging removal processes,the causes and hazards are analyzed,and corresponding solutions are put forward.