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Tomax 8 ¼” X-Series aST

The “X” means extra flexible and reflects an extensive operational capability in terms of drilling parameters and well curvature.

With its 8 ¼” OD, the tool provides for improved flexibility in terms of bit size, but with a yield capacity comparable to the larger tools. A large stroke capacity of 10” or 0.25m gives the tool a working range that makes it an optimal solution for performance-drilling using aggressive cutter structures without risk of initiating vibrations and stick-slip in challenging layers.

The inner diameter is 2 ¾” and presents no restrictions to drop-balls. The pressure loss through the tool is minimal (less than 30 psi at 1200 GPM or 2 bar at 4500 lpm ) and the tool can be configured for high temperatures.

Length5.44 m17.85 ft
Max. OD209.6 mm8.25”
Min. ID70 mm2.75”
Connection topAPI 6 5/8 REG boxAPI 6 5/8 REG box
Connection bottomAPI 6 5/8 REG pinAPI 6 5/8 REG pin
Tomax anti stick slip downhole tool 8 ¼” X-series
Closeup of a Tomax AST
The 8 ¼ X-Series presents a unique dynamic stroke that allows for regulating the loading of the drill bit at significant ROP. The capability eliminates the need for special configurations – even in combination with under-reamer.
A new deep-drill machining technology has been used for manufacturing the 8 ¼” X-Series AST. This has replaced the need for an internal joint near the top of the tool and provide the same ultimate tensile capacity as on the larger tools but with a significantly improved bending capability. Compare ASTs for further configuration details.

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