Analysis of the Axial Dynamic Behavior During Installation of Surface Casing in Deep Water Well Construction

摘要

Well construction in increasingly water depths makes harder to design, manufacture and install surface casings to support loads imposed on them. In addition to the static loads, that designers are accustomed, dynamic loads are present in surface casing due to rig movement caused by sea waves. In recent history, there are some cases of unexpected break off or disconnection at the top while running surface casing. The objective of this work is to model and analyze the axial dynamic behavior and loads generated by the movement of the tubular element system during installation of surface casing in water depths up to 3,000 meters and casings up to 1,500 meters. The idea is to verify if this dynamic behavior compromises the surface casing or the drill pipe used, leading to failure. To achieve this goal, an analytical model is obtained for the equations of motion governing the tubular element system while running surface casing. From the solution of the equations obtained, several simulations are made in various scenarios to support the conclusions regarding the behavior and the consequences that these movements can cause are predicted. Although this study uses some equations and modeling already published, the modeling of the boundary condition on the float shoe and the application of models and analysis of surface casing axial dynamic behavior are unprecedented.