Drilling Systems

Overburden Drilling Systems

Symmetrix Systems -- The all-in-one Symmetrix design is an ingeniously patented simple concentric method of drilling through overburden using casing. The expediency and high capability of Symmetrix can drill straight holes at any angle whether vertical or horizontal and to a depth of over 100 meters.
All components in the patented Symmetrix system work as one efficient drill bit with features that include:
- Pilot bit with large internal flushing grooves
- Symmetrical ring bit (reamer) with internal bayonet coupling
- Casing shoe for driving of casing
- Pilot bit is attachable to any common DTH hammer shank or top hammer rod thread

Three Wing Under Reamer -- The under reamer has an extendible arm bit and is considered superior to a one-sided under reamer primarily because of the three (3) arms that extend to ream a full gauge (360 degree) hole. The under reamers swing out on only one side, drill more slowly, and are not always straight.

The Full Gauge UR resembles a conventional hole opener with extendible arms covering 360 degrees of the hole circumference, minus three air slots. The Full Gauge UR is similar in size to a conventional bit.



Under Reamers by America West Drilling Supply -- The Percussion under reamer is a two-piece tool that includes a Driver section and a Bit section. The Driver or splined portion fits into the Down-the-Hole Hammer and is similar to a conventional hammer bit, with the exception of carbide buttons. Instead it is the holder for the Bit section, which has carbide buttons.

The Bit section has a pilot portion that is out of center to the rest of the Bit and the drill string. As the Hammer rotates, the Pilot section attempts to center itself, similar to a caster wheel. The friction of the nose of the Bit on the well bore wall helps pull the nose out from under the casing, thereby drilling a larger hole than OD of the drive shoes on the casing. The whole bit swings out.

Additionally, the Bit has a short heavy pin on the topside that fits into a pocket on the Drive. A small portion of the air escapes between the wall of the driver pocket and the pin portion of the bit. This keeps the Bit in alignment with the drill string for retraction.

The Percussion under reamer will incorporate a welded drive shoe on the bottom of the casing, with a small compact Missile down the hole hammer serving as guide and driving force for the under reamer. During drilling operation Cuttings will be diverted up the casing past the drill steel, which will then be exited through a common diverter box that has been attached to the rig's rotary head. Unconsolidated formation areas that might have created problems in the past are now possible to drill and no longer present major problems, only challenges.