Research On Key Technology Of AFAT In Deepwater

Axial Force and Alignment Tool(AFAT) is a special equipment for installing and maintaining the oil and gas pipelines in deep water. Its main function is to adjust the position between the new pipelines and the old pipelines, and meet the work requirements of the Flange Conncetion Tooling(FCT). The technology has been monopolized by foreign companies for a long time.The research subject comes from the project "The study of submarine pipeline connection technology in deepwater"(Project number:2006AA09A05-4), which is a sub- project of the national "863" program——the laying technology of submarine pipeline. This thesis focuses on the research for the key technology of AFAT, which is used to align the submarine 24" pipeline under the water of 3000m depth. The purpose of the thesis is to R&D AFAT with independent intellectual property right.Firstly, based on research of the development status of the AFAT aroud the worldwide, the general scheme of the AFAT is introduced, mechanical structure is also designed, the position of center of gravity and buoyancy of the AFAT and the placed position of the pipeline are analysed.Secondly, the clamping device and the alignment device are studied, about clamping device structure analysis, cylinder force determination, design of the clamping cylinder,strength check of the pipeline based on the thin-walled theory, and study on the alignment device from two aspects:one is horizontal adjustment, another is longitudinal adjustment.Thirdly, hydraulic system of the AFAT is designed, about parameter calculation of the hydraulic actuator, hydraulic pump selection and design of hydraulic circuit. Finally, the strength of the pipeline and main parts of the AFAT are checked by using the finite element analysis software ANSYS,and the kinematics simulation of the clamping mechanism is completed by using the dynamic Analysis software ADAMS. The results show that the rationality of the structure satisfied the requirments of the AFAT.