Dual-Acting Circulating Sub

The Dual-Acting Circulating Sub has been designed to save wear on Bottom Hole Assembly components and to provide an increased flow rate through tools after activation.

Dual-action-circulating-sub A drop-ball Circulating Sub is typically used on drilling or milling BHAs.  At the required depth a drop-ball is launched into the Coiled Tubing or Jointed Pipe and pumped down to the Circulating Sub.  When the ball seats and pressure is increased, a piston within the tool is shifted, which allows flow to be directed to the annulus. This isolates further flow through the motor and allows the flow rate to be increased.  The resulting higher annular flow assists in cleaning debris from the wellbore.

The Circulating Sub can also be fitted with a burst disc port which allows circulation to be regained in an emergency situation.

Design Features

  • Easily Field Re-Dressable
  • Optional Rupture Disc Available
  • Easy to Assemble & Operate
  • Surface Indication of Successful Activation
  • Various Circulation Port Sizes Available to Suit Expected Well Conditions
  • Interchangeable Circulation Piston Allows Different Sizes of Drop-Balls to be Used