Research On Vibration Characteristics And Design Of The Deep Water Pipeline Occluder

Pipeline transportation is an important method of transportation in the offshore oil exploration project.Its submarine pipeline is an important part of the oil and gas transmission system.Because of the complexity of the marine environment,submarine pipelines are vulnerable to various forms of damage and are prone to various forms of failure as the service life of pipelines increases.Oil leakage will inevitably occur when submarine pipelines are damaged,Not only will cause huge economic losses,but also leaked oil will cause serious pollution to the marine environment,the pipeline must be promptly repaired accident,this paper designed a submarine 1500 m deep seabed pipeline plugging maintenance Adapter.Based on the analysis of the working principle of the subsea pipeline occluder,this paper combined the characteristics of the marine environment and the main design parameters to determine the overall program of the device,and detailed design and analysis of the key components.The occluder is composed of an anchoring mechanism,a sealing mechanism,a power device,a guide device,a hydraulic system and a quick-change device.In this paper,the sealing mechanism of the occluder and the stress-strain process of the sealant is analyzed.The paper makes it clear that the contact pressure between the sealing surfaces is the main index to measure the performance of the occluder.Several different sealant structures are designed and comparatively analyzed by finite element simulation.Choosing one of the sealant structures and making detailed optimization design.This paper designs a kind of inclined lifting mechanism that can provide larger radial anchoring force by providing smaller axial force through the power device,Based on the analysis of the working principle of the occluder anchoring mechanism.Based on the analysis of the stress of anchoring briquetting,the embedding depth analysis and the finite element simulation analysis is carried out.The anchoring experiments on the anchoring briquettes showed that the friction coefficient was not constant,the relationship between the contact surface friction coefficient and the external load and the relationship between the embedded depth and the applied load were obtained.The experimental results are consistent with the theoretical analysis.The correctness of the theory is verified,and the anchorage block is still intact after overload test,indicating that the compact is strong enough.After installing the occluder,a sudden change pipeline will be formed,leading to the change of the fluid shape in the pipe.The Bernoulli equation of the total fluid flow is established,the fluid shape in the pipe is analyzed,and the FLUENT is used to simulate and analyze the variation rule.In this paper,ANSYS finite element analysis software is used to the modal analysis of occluder,natural frequency and natural mode are obtained,and vibration characteristics are analyzed.Based on this,the response of the occluder under external excitation is analyzed.The results show that the vibration caused by the fluid change at the orifice and the ocean current will not have a serious impact on the occluder performance.Occluder can be optimized on this basis,indicating the direction for the follow-up study.