Roller Reamer Seals
Kalsi-brand rotary seals are used in oilfield roller reamers to achieve longer operational life by retaining bearing lubricant and excluding drilling fluid and cuttings. The ACS seal, which is available in HNBR and FKM, is our most popular roller reamer seal because it doesn’t require lubricant overpressure. The FKM roller reamer seal is offered in a special geometry for higher temperature operation.
Sealed roller reamers are used by the oil & gas industry during well drilling operations. The primary purposes of roller reamers are to ream the wellbore to size, eliminating tight spots caused by a worn, under-gauge drill bit, and to help to true up the wellbore, smoothing over ledges and other wellbore defects that can hamper other well preparation operations. The use of sealed roller reamers also helps to locally center the drill string, serving as a stabilizer. This helps the drilling operation to continue in the intended direction, by minimizing drill string angle-induced course deviation.
A typical sealed roller reamer employs a set of at least three roller-cutters that are mounted in an equally spaced fashion around a longitudinally slotted hollow body that is threaded to the drill string. Each roller-cutter is mounted in, and projects slightly from, a separate longitudinal slot. As the drill string rotates, the roller-cutters roll around the wellbore, reaming the wellbore to size. The rolling action helps to reduce drill string-to-wellbore friction, compared to conventional stabilizers. The reduced frictional torque helps to minimize violent stick-slip related high speed drill string rotation and vibration, which helps to prolong the life of the various components of the bottom hole assembly.
Sealed reamers require that a reservoir of bearing lubricant be provided. They also require that the pressure of the lubricant be balanced to the ambient pressure of the well, so that the roller reamer seals are not exposed to high differential pressure. This typically involves the use of a pressure-balancing piston. For examples of sealed roller reamers that incorporate pressure-balancing pistons, see expired US Patent 4,542,797 and expired CA Patent 2,154,285.
For additional information about Kalsi-brand roller reamer seals, call 281-240-6500, or contact us by e-mail.