The Design Of The Deepwater Pipeline Internal Blocking Device And Experimental Reseach Of The Sealing Structure

Currently, because of the rapid development of our country, the demand of energy is far from the production of land oilfield. Our country is gradually increasing exploitation of undersea oil. There are more than 3,000km submarine pipeline laying in china. Sometimes the damage of submarine pipeline may occur. The damage would have huge influence on our country and the ocean environment. The disastrous oil spill has made a wake-up call for CNOOC engineering which happened in the gulf of Mexico in 2010 and the leak at penglai 19-3 oil field in Bohai Bay in 2011. This paper presents the design of the deepwater pipeline internal blocking device aimed at developing a method to repair the emergency plugging subsea pipeline,which has our independent intellectual property and reaches the international advanced level.On the basis of investigation and analysis of domestic and foreign relevant technology,researching the key technology of the switching system in the deepwater pipeline internal blocking device, combining the main technical requirements and particularity deepwater working environment,the paper makes the overall design program for the deepwater pipeline internal blocking device and completes the designing and checking of the anchoring device,sealing device, guiding device, dynamic device and hydraulic system.The anchoring device is one of the key techniques for the deepwater pipeline internal blocking device. Basing on the ramp force amplifier and the principle of elasto-plastic mechanics, the paper completes the structure designing and build 3D model and mechanics model. This paper analyzes strength of the key components in the anchoring structure,Focusing on the design of anchor block,material choice and contact analysis of anchor block and pipe wall, which are the theoretical foundation of the design of the anchoring device.Sealing performance of the sealing device is very important to guarantee the reliable operation of the deepwater pipeline internal blocking device. On the basis of analysis of its operating conditions and technical requirements, the paper designs a rubber barrel to suitable deepwater 18" sea tube combining with the domestic and foreign design ideas of rubber barrel.The paper builds the mechanical model of sealing rubber barrel which in the early closure phase and working phase,and analyzes the nonlinear of rubber barrel to verify the rationality from the theory of rubber barrel structure designing. Besides, the paper completes the design of the sealing device, builds its 3D model, and analyzes the strength of the key parts.Through the axial compression test and critical setting force test, the paper determines the optimum hardness of the rubber barrel with the sealing test device, and selectes the form of rubber barrel to meet the actual working conditions through holding pressure test in different combinations of the rubber barre. The test results would verify the accuracy of the theoretical analysis and the reliability of the sealing device.