Circulation:

Terms Related to Circulation

• Reverse circulation

  The course of drilling fluid downward through the annulus and upward through the drill stem, in contrast to normal circulation in which the course is ...

• Normal circulation

  The smooth, uninterrupted circulation of drilling fluid down the drill stem, out the bit, up the annular space between the pipe and the hole, and ...

• Circulation sub

  A downhole tool typically used with motors or assemblies that restrict the allowable fluid-circulation rates. When operated, the circulation sub allows a higher circulation rate to ...

• Break circulation

  1. To start the mud pump for restoring circulation of the mud column. Because the stagnant drilling fluid has thickened or gelled during the period ...

• Mud circulation

  The process of pumping mud downward to the bit and back up tot he surface in a drilling or workover operation. See normal circulation, reverse ...

• Circulation valve

  An accessory employed above a packer, to permit annulus-to-tubing circulation or vice versa.

• Mud pit

  An open pit dug in the ground to hold drilling fluid or waste materials discarded after the treatment of drilling mud. For some drilling operations, ...