The WOOKE symmetric/Concentric drilling system is designed to drill and case a hole simultaneously through unstable ground conditions. The driver bit incorporated with a reamer or reusable ring makes a full face head design which significantly improves the penetration rate and hole straightness of drilling. The internal flushing grooves together with the built-in casing shoes gives a good seal to the button of the drilling hole, and thus minimizing the disruption of the surrounding of the drill hole.

The Symmetric Casing Drilling Systemconsists of three parts: central pilot bit, casing shoe and symmetrical ring bit. The central pilot bit drills away the center part of the hole and guides the drill string, incorporated with a irretrievable symmetrical ring bit make a full face drill bit. The casing shoe is welded or threaded to a casing pipe, which is pulled down by the impact of the DTH hammer and central pilot bit. The symmetrical ring bit and casing shoe assembly is locked into central pilot bit with a hammer shank, and the ring bit is to drill the segment the casing to advance down the hole. The pilot bit's upper shoulder engages the shoulder of the casing shoe. DTH hammer's impact energy is transferred through the pilot and ring bits, crushing rock, part of impact energy advances casing. On completion of drilling and casing, the drill string with pilot bit is retrieved by a slight reverse rotation to unlock the bayonet coupling. The ring bit stays in the hole, and can be recovered only if the casing is retrieved. Drilling continues to the desired depth in the bedrock using a conventional drilling.

Symmetric Casing Drilling System Features and Advantages:

Stable and reliable working performance

Full face head design for faster penetration and straighter hole

Less torque is required than eccentric drilling

Can drill in vertical, horizontal or any direction

Minimize disruption to the drilled hole

Effective cuttings removal

Unlocking-relocking easily

Easy to operate and system security

Varied ring bit diameters to suit different casing requirement

The less vibration of drill rig

We provide the bit shank ranges from 3” to 10”.

The Eccentric Casing Drilling Systemis the most economical solutions for casing drilling in average ground conditions. They are very popular with drilling contractors for casing in water wells, geothermal wells, medium mini-type grouting hole of building, dam and harbor project, and shallow micro-piling work. Because of the ingenious reaming wing, the bit is retrievable and can be used again. The Eccentric Casing Drilling System is ideal for short holes in homogenous overburden, thanks to outstanding advantages as simple structure, easy operation, retrievable drilling tools, long service life and good quality. Drilling characteristics of The Eccentric Casing Drilling Systems are essentially the same as for the DTH hammer drilling method, like:

Rapid removal of cuttings;

High penetration rate, especially in resistant rock formation (e.g. basalt);

Easy soil and groundwater sampling during drilling;

Possible to measure yield estimate at selected depth in the formation;

Advantageous in unconsolidated formations with a high risk of caving (this is probably the most important feature).

We provide the bit shank ranges from 3” to 10”.

We can design and manufacture according to customer's requirement of the bit dia, No. of the air holes, carbide button shape and the face shape.