| 摘要 |
A transition piece is provided near an end of a screen assembly to allow transition from a lighter weight and collapse resistant pipe under the screen sections to a heavier wall and higher collapse strength pipe between the top of the screen and the isolation packer. When a screen out occurs, the heavier wall pipe can handle the new pressures that are applied to the formation and to the tubular to try to collapse it. The screen portion can still be built with thinner wall pipe as the screen out condition protects that pipe from collapse pressure because the fully gravel packed annular space keeps the surface applied pump pressure from exerting a collapse force on the base pipe under the screen. |
