Varel Unveils New Drill Bit Series

Varel International announced the launch of the A-Force roller cone bit series, a line built specifically for underbalanced applications, including air, foam and mist.

A-Force bits bring together new roller cone technology and improved materials resulting in a drill bit with increased speed, longevity and steerability.

Chris Byrd, vice president, Roller Cone Business Unit, said the A-Force series technology grew out of Varel's roller cone research and development efforts.

"Varel has built a solid foundation in roller cone technology and now we are able to exploit the benefits of our developments. The A-Force series includes patent-pending innovations, which assists in the reduction of heat and wear in internal roller cone bit components. This, in turn, leads to longer bit life, improved drilling economics and an enhanced drilling program for operators," Byrd said.

The technology in the series works to improve the longevity of the seal and the bearing system and to extend the life of the drill bit. Key features include:

  • Bearing Seal — A-Force bits include a heat shield disc deployed between the seal and the bearing. This shield acts as a thermal insulator, protecting the seal from excessive thermal energy, lowering the operating temperature for the seal and extending seal life.
  • Conical Seal Gland — The bits are also equipped with a conical seal gland that positions the seal in such a way that it can better handle pressure fluctuations and still maintain a preferred sealing location and interface. This is especially important with the high internal bearing pressures that can be experienced in air, foam and mist drilling.
  • Higher Load Capacity Journal Bearing — The series incorporates a more robust and more tightly toleranced journal bearing capable of supporting increased levels of weight on bit. This translates directly into longer, more reliable bit runs.

A-Force series drill bits include additional material improvements:

  • A new grease formulation that is stable at increased operating temperatures: This grease reduces internal bearing heat generation allowing the bearings to remain cooler.
  • A more wear-resistant hardmetal inlay, shown to provide a 54 percent reduction in wear, incorporated onto the journal surface: This hardmetal works to prevent wear to the journal surface extending the effective life of the bearing.
  • Redesigned head forgings: The benefit is increased leg strength, reduced bit length and improved steerability.
  • Inclusion of Varel's patented High Energy Tumbled (HET) processed carbide inserts: A-Force bits are equipped with both cutting structure designs and carbide grades specific to underbalanced applications.

A-Force bits are available in diameters ranging from 6-1/8" - 12-1/4".