Underreamers Overview


Roller Cone and Drag Type Underreamers are just two more examples of our goal to bring expensive Oil Field technology to other drilling markets at an economical cost. We have been manufacturing both types of Underreamer designs for over 20 years and based on the feedback from our customers out in the field, we have been able to offer continual improvements. We also offer a Casing Cutter that utilizes our Roller Cone body. This dual purpose and versatile tool’s design makes it easy to switch between the roller and casing cut off arms. The casing cutter arms incorporate uniquely heat treated blades that are field-replaceable.  This innovative tool activates pneumatically, or hydraulically at about 100 PSI, and comes with a spare nozzle to accommodate most pump pressures. The cut off tool is primarily used to remove casing from the borehole for well abandonment purposes.

The primary use for the underreamers is to open up the borehole below the casing. Most drillers are trying to straighten up a dogleg down in a hole, which may be preventing advancement of the casing. Other uses include opening up zones down in a hole to increase the yield of a well or seal off salt water intrusion from the bottom of the hole. The construction industry has used Underreamers for tie-back or anchor holes in any type of dirt, rock, or concrete formations. Our Underreamers and Casing Cut Off Tools can be opened up anywhere down in a hole and as many times as needed, but with the undereamers you must have adequate annular space for the blades or rollers to open up. Most drillers pull the casing up 3 or 4 feet and lower the underreamer below the casing and then open the tool and start drilling. The tools operate with either air or fluid pressure and require as little as 60 - 100 lbs. of pressure to force the cutter arms out. The bodies and cutter arms are manufactured from heat-treated steel. The piston is carbonized steel to reduce abrasion and features a replaceable tungsten carbide jet nozzle to adjust to your individual compressor or mud pump output. Additional circulation holes have been added to the side of the piston body to keep the cuttings out of the cutter slots. The simple, rugged design features easily replaceable components for long-term, trouble-free operation.

The operation of our Underreamers is very simple. The tool is hydraulically operated by pump pressure which forces a spring loaded actuating piston downward. A cam attached to the lower end of the actuating piston forces the cutter arms out to the desired cutting diameter. When the pump pressure is shut off, a coil spring forces the piston upward causing, the cutter arms to retract back into the body. We can custom manufacture any size underreamer to meet your individual requirements.