137 Research of Milling Control Technology for Permanent Packer in Practice

In order to adapt the use of workover rig for offshore completion and workover operations, it generally uses two different drive mode of milling, downhole motor and surface turntable, in dealing with deep inclined well permanent type packer issues. In this thesis, the main focus is on control technology of milling operation to the permanent packer. At the same time, the forces of pipe string were analyzed and the axial forces, torques and frictions and other mechanical calculation models of the pipe string were established under two kinds of drive modes. Through the results of analysis of pipe string force, it accesses the risks of the milling operation, optimizes the parameters of downhole tools and operation methods in milling operation.