Research On The Key Technology Of The Installation Of Deepwater Subsea Tree

With the increase of water depth, greatly improve the deepwater Subsea Christmas tree installation difficulty and risk, installation technology has become one of the key technology of deepwater Subsea Christmas tree need to break through. In this thesis, the deepwater Subsea Christmas tree installation as the breakthrough point to study.Firstly, briefly introduced the common underwater installation methods, and select the drill pipe direct installation method to study, comparison and analysis of the different function and structure of the Vertical and Horizontal Christmas tree, analysis of horizontal Christmas tree is more suitable for deep water. Then a detailed analysis of the installation process of Horizontal Christmas tree in the shallow water and deep water.Then by use of the fault tree analysis method to analysis risk for deepwater Subsea Christmas tree installation process. Through the fault tree qualitative analysis:the dynamic positioning of the platform and heave compensation system, the marine environment force on the tree body decentralization affect installation. And the reliability of the tubing hanger running tool has a great impact on the tubing hanger installation. The fault tree quantitative analysis, when the data is very difficult to obtain, use expert judgment method and combined with the fuzzy mathematics theory to solve the happening probability of the base events.Finally, using the improved Morrison equation solving the transverse force of the Subsea Christmas tree and lowering drill pipe composition of suspension system, and obtain the effective depth of interaction mainly concentrated in the distance the sealevel 100 meters water depth range. Then using joint simulation of ANSYS and ADAMS method to analysis the influence of the operation platform heave motion when the Subsea Christmas tree installation. Analysis of the suspension system of the great inertia, a small fluctuation in acceleration will make lower mutation string stress greatly. Therefore, special attention should be in the installation process of decentralization of Subsea Christmas tree. Considering the passive compensation of the lower the drill string, in achieving the premise of equal compensation rate can effectively reduce the heave compensation system energy consumption, in the premise to achieve equivalent compensation rate can effectively reduce the heave compensation system energy consumption.