Through Tubing Underreamer

The 2-blade through tubing underreamers are designed to go through very small restrictions and open up to mill out obstructions such as cement, sand and scale in casing.  These tools have also been used to mill-up cast iron and composite bridge plugs as well as other restrictions.  The underreamer is run with a pilot mill below the underreamer.  The pilot mill is typically sized to the maximum OD possible to run through tubing, landing nipples, packers, etc.  Some sizes of underreamers can also be run in tandem to allow even larger OD cleanout.

This underreamer is designed to perform well on coiled tubing with mud motors or on threaded tubing.  The blades are actuated by pump pressure, which forces a piston to expand the blades into their operating position.  The underreamer requires approximately 100-200 psi differential pressure across the tool to open the blades and salt water with 40-60 sec viscosity is recommended for cutting removal.  The tool is designed to allow fluid to flow over the blades to remove cuttings.  The typical expected milling rate is 1ft every 3 to 4 minutes.  Once cutting is complete and pump pressure is shut off, the blades can retract back into the body.

2-Blade Underreamer Max Cut Size

Tandem Underreamer Max Cut Size (4 Blades)

* Custom sizes available upon request

* All tools can be run in tandem for redundancy and full clean‐out reliability

* Cross overs and oversized pilot mills available upon request.