Circulation Control Joint
The Baker Hughes circulation control joint is a multipurpose tool that provides a means of establishing circulation at a predetermined hydraulic pressure. It can be used as a pump-out, kick, run-in, or drain sub by varying the particular control washer/rupture disc/restriction plug combination.
The standard circulation control joint has an inner bore profile that forms a seat for restriction plugs fitted with a bit nozzle. The control washer and bit nozzle inner diameters (IDs) can be varied to obtain the correct relationship between mud flow and pressure drop to burst the rupture disc and establish the desired flow rate. The circulation port can be resealed at any time by removing the standard restriction plug (short fishneck) and inserting an extended (long fishneck) restriction plug. Both restriction plugs can be recovered with slickline using a restriction plug spear.