Scratcher:

By rotating or moving the casing string up and down as it is being run into the hole, the scratcher, formed of stiff wire, removes the cake so that the cement can bond solidly to the formation.

Terms Related to Scratcher

• Bradenhead squeeze

  A process used to repair a hole in the casing by pumping cement down tubing or drill pipe. First, the casinghead, or bradenhead, is closed ...

• Casing pack

  A means of cementing casing in a well so that the casing may, if necessary, be retrieved with minimum difficulty. A special mud, usually an ...

• Filter cake

  1. Compacted solid or semisolid material remaining on a filter after pressure filtration of mud with a standard filter press. Thickness of the cake is ...

• Mud-off

  1. To seal the hole against formation fluids by allowing the buildup of wall cake. 2. Block off the flow of oil into the wellbore.

• Centralizer

  1. A bladed or bow spring tool that helps center tools or pipe in the wellbore. 2. A mechanical device to position casing concentrically in ...

• Differential sticking

  A condition in which the drill stem becomes stuck against the wall of the wellbore because part of the drill stem (usually the drill collars) ...

• Casing centralizer

  1. A device secured around the casing at the regular intervals to center it in the hole. Casing that is centralized allows a more uniform ...