Hydraulic UnderReamer

Product Details

The Hydraulic UnderReamer gives the user the ability to enter a producing wellbore to clean out the casing without having to remove the production tubing. Another advantage of the Access Downhole Hydraulic UnderReamer is the ability to stack them to further increase the range of milling versus the effective tool OD.

One facet of the design of the Hydraulic UnderReamer is the positioning of the jet nozzles to both clean and cool the blades. Another feature is that by adding tool stages (a stage is one UnderReamer section), the operator can extend the reach of the same OD UnderReamer. Couple this with a high-speed, low-torque motor and you can efficiently clean out large IDs in small swathes safely.

While increasing the number of stages adds operational efficiency, so also does properly controlling downhole conditions. The Hydraulic UnderReamer works best when taking 10ft–20ft of debris or fill at
a time. This is best accomplished by reaming down, then swabbing up with the lose cuttings, then making the second pass to recover the footage and get 10ft–20ft more, depending on the ROP (rate of penetration).

The blade style can be altered based on the obstructions, making both the cutting media and the blade shape conform to the best method
for the fill. The blades can also be swapped for slips or slick segments to convert the UnderReamer to the Hydraulic Anchor, or the Hydraulic Stabilizer, respectively.

Major Benefits

  • Can be stacked to greatly increase the maximum millable ID versus the tool OD
  • Tool design allows for a changing of function by a simple blade swap (from UnderReamer to Anchor to Centralizer)
  • Ability to clean out large casing without removing production tubing


Tool OD (in) Tool Joint Connection Max Reach Std. 2 Stage Overall Length Std. 2 Stage Tensile YieldTorsional Yield
1.6881.00in AMMT3.50 in32.00 in61,870 lbs920 ft-lbs
2.1251.50in AMMT4.875 in36.00 in115 ,290 lbs2,150 ft-lbs
2.8752.375in PAC8.50 in40.00 in244,720 lbs4,930 ft-lbs
3.1252.375in Reg9.875 in48.00 in365,260 lbs7,280 ft-lbs
4.7503.500in IF16.00 in60.00 in572,690 lbs18,090 ft-lbs

* Custom tool joint connections available upon request, may change specifications.
** All listed values are calculated and include NO safety factor. They are also subject to a +/- 20% variation due to the mechanical properties of the steel. All safety factors applied by the end user should take field conditions into consideration. The listed values DO NOT constitute a guarantee, actual or implied.