Overburden Drill Systems and Accessories

Advantages of SDS:

• Low capital investment
• High drilling performance
• No rotation of the casing
• Compatible with most drilling rigs
• Virtually no casing stress
• Casing is simultaneously lowered by the guide device and to deeper depths than other methods allow
• Cost and on-site time reduced due to better penetration rates, easier bit changes, and stable hole conditions
• Smaller pilot bit for faster and better penetration

Applications:

• Blast holes
• Water supply wells
• Bridge and building foundations
• Standard slant or horizontal drilling
• Mining air holes
• Environmental monitoring wells
• Grouting operations
• Seismic shot holes
• Soil sample and geotechnical applications
• Ground anomaly and tiebacks
• Storage caverns and dam

Accessories Available with SDS:

• Drop Off Ring (DOR)
• Drill pipe and subs
• Threaded casings
• Casing drive shoes
• Hydraulic casing pullers
• Stabilizers
• Discharge heads
• Casing wing-nuts
• Shock subs
• Drill bits
• Fishing tools
• Air swivels

Overburden Drill System

Assembly of the Stratex System

The Stratex Drilling Method is used with air rotary drilling rigs and most manufacturers' downhole hammers. The drill rod is connected to the rig top drive using a changeover sub or swivel sub. The drill rod is then connected to the down-hole hammer by the same method. The chuck nut and split rings are removed to insert the guide device shank and secured by replacing the split rings and chuck nut.

The reamer bit, in the closed position, is now inserted into the casing shoe. Since the percussion hammer is at the bottom of the hole, working directly above the drill bit, the force to pull down the casing tube is transferred by way of the casing shoe. The exhaust air from the drill redirects the loose cuttings up through the groves on the guide device, forcing them up between the drill rod and the casing wall out through the discharge head, which is attached to the casing tube. By using a discharge head, drilling is not only safer but also environmentally cleaner. Stratex can be used with foam or water to aid in cutting removal.

Good Flushing

Good Flushing is essential with any successful drilling operation or in using an overburden drilling system. The Stratex System provides air jets above and below the guide device, creating a vacuum across the face of the reamer bit, removing the cuttings with greater annular velocity. The gauge carbides along the side of the pilot and reamer bit act to crush the cuttings into finer particles, the majority of which are removed from the hole. The remaining cuttings are forced back into the walls of the cavity, leaving less material to be extracted from the hole.

Advantages:

• Efficient removal of cuttings from above the guide device, which prevents the hammer from jamming and torque problems
• Removal of fine cuttings from around the bit system and casing creates less friction and achieves deeper depths and easier casing removal
• Reduction in losses due to circulation problems by increased vacuum in cutting removal
• For unique applications, the annular velocity can be increased by changing the airflow in the reamer pilot system

1. One-piece reamer and pilot bit
2. One-piece guide device and shank
3. Casing with shoe sleeve
4. Casing
5. Wing-nut centralizing system
6. Drill rod
7. Casing adapter
8. Discharge head
9. Swivel sub

Drilling Rod

Wiper Cover
Wipers

Discharge Body

Discharge Clamp
Adapter

Blank Casing End

Adapter Clamp

Replaceable Grippers

Pin End

Box End

Casing

Hammer Shank

Guide Device

Casing Shoe

Reamer Bit

The Stratex System utilizes a one-piece reamer and pilot bit that moves outward to full open position on an eccentric shaft by rotating a half turn to the right.

This reamer pilot bit system opens a larger diameter hole than the diameter of the casing. The casing is simultaneously lowered into the hole as the reamer pilot bit drills. The pilot bit is rotated at 10 to 40 rpm while drilling with the hammer.

When the designated drilling depth is reached, the reamer pilot bit system is retracted into the casing by applying slight tension and reversing the direction of the drilling rotation. The design of the reamer pilot bit system incorporates a closed bearing method that makes the loss of the pilot bit virtually impossible. This bit system, in the closed position, is easily removed through the casing shoe and casing.

Normal Max - Hole Depth (ft)

1. One-piece shank and guide device manufactured from the highest quality material with stringent quality control.
2. Air jets are used to prevent any malfunction of the opening and retraction of the reamer pilot bit operation and the clearing of cuttings above the reamer pilot bit system.
3. Sealed bearing system for ease in rotating the eccentric bit outward or retracting it into the casing.
4. Casing with shoe: Casing may be supplied with plain or threaded ends.
5. Grooved bypass directly above the lock system to clear cuttings and ensure complete drilling face contact.
6. Tapered shoulder on the reamer bit eliminates casing binding and assists in the retracting of the reamer bit into the casing.
7. One-piece reamer and pilot bit manufactured from the highest quality material, with stringent quality control.
8. Gauge protection carbides on heavy duty, one-piece pilot and reamer bit.
9. Dome carbides on heavy duty pilot and reamer bit.

• High performance drilling
• One-piece reamer
• One-piece guide device
• Made from tough heat-treated alloy steel
• Studded with an aggressive array of tungsten carbide inserts
• Lower drilling costs per foot
• Guaranteed performance*
• Guaranteed service
• Large range of accessories
• Manufactured under strict quality-controlled conditions

*When used in conjunction with manufacturer's recommendations and specifications.

Used when concentric drilling is a requirement:

• High performance drilling
• One-piece reamer
• One-piece guide device
• Made from tough heat-treated alloy steel
• Studded with an aggressive array of tungsten carbide inserts
• Lower drilling costs per foot
• Guaranteed performance*
• Guaranteed service
• Large range of accessories
• Manufactured under strict quality-controlled conditions

*When used in conjunction with manufacturer's recommendations and specifications.

Recommended Maximum Air Pressure for Stratex Drill Systems

The maximum recommended air pressure for Stratex drilling with down-hole hammers is 12 bar, which equals 210 psi.

Rotation speed depends on the size of the Stratex bit and the formation being drilled. The rotation speed may have to be varied as the formation changes. The table shows recommended rotation speeds for the various Stratex sizes.

The latest concentric under reamer used for large diameter requirements:

• High performance drilling
• Five retractable wings
• Made from tough heat-treated alloy steel
• Studded with an aggressive array of tungsten carbide inserts
• Lower drilling costs per foot
• Guaranteed performance**
• Guaranteed service
• Large range of accessories
• Qualified, dedicated staff
• Manufactured under strict quality-controlled conditions
• Sizes from 20"
• Custom sizes available

• LH/RH thread
• Alloy steel threaded casing ends
• Flush joints
• API and custom-threaded specs available
• Casing sizes from 70 mm
• Metric and Imperial sizes available
• Drill rod sizes from 2"

Overburden Drill Systems

ACCESSORIES

• Drop-off Ring (DOR) bits
• Drill pipe and subs
• Left threaded casings (left-hand HT allow ends)
• Casing drive shoes
• Stabilizers
• Hydraulic casing pullers
• Discharge heads
• Casing wing-nuts
• Shock subs
• Drill bits
• Fishing tools
• Air swivels

Manufactured under ISO 9001 quality control

Very happy with the Stratex Eccentric
and Casing Puller System. Excellent turn
around time and knowledgeable staff. Highly recommended to users and distributors."

-N&N Drilling Supply, PA, USA