Once bore a hole in the unstable soil formation, there is potential risk of hole collapsing. Casing drilling is an ideal drilling method that combine the drilling and casing process together to stabilize the hole. Powered by DTH hammer, the casing system has a pilot bit which drives a ring bit to drill a hole wide enough so that a casing tube can slide down to the hole. As the drilling process and casing process are performing at the same time, the casing tube can stabilize the hole immediately.

Overburden casing drilling system can be classified into concentric casing system, eccentric casing system and slide block casing system.

Concentric casing system also called symmetric overburden casing system, it can drill a hole at any angle (including horizontal) and the hole depth can be up to 100m. Concentric overburden casing system is composed of a central pilot bit, ring bit (reamer), casing shoe

The central pilot bit is attached to the DTH hammer and the casing shoe is welded to the casing tube. Powered by the DTH hammer, the central pilot bit drives the ring bit to drill a hole large enough and meantime the casing tube slide down to stabilize the hole. Once drilling the hole into the required depth, unlock the pilot bit by reverse rotation of the drilling string and then pull out the pilot bits through the casing tube. As for the ring bits and casings, they can be left in the hole for the permanent casing system or can be retrievable for the retrievable casing system.

Advantage:

• Drilling a hole straight and fast, even drilling in the gravel, sand, pebble formation;

• Requiring less torque of the rig, even the drilling rig with small torque can drill a large hole;

• It’s easy to unlocking and relocking the concentric casing system due to its simple structure;

• Drilling a straight hole at any angle;

• It’s easy to operate and cost-effective

Casing Tube

We have a range of casing tube from diameter 108mm to 377mm for concentric/ eccentric casing system.

High drilling efficiency

Due to its good performance of high penetration rate and minimal deviation tendency, ourDown-the-hole drilling toolshave been exported to many different countries such as USA, South Africa, Ireland etc and won a good feedback.

Quality assurance

With many years experiences of production of Down-the-hole drilling tools, the concentric casing system we made have long service life and lower air consumption.

All around after-sales service

Our sales will response to any questions within 24 hours once we get. We pay great attention to the feedback from clients and satisfy them both on products and services.

warranty:

The warranty period is six months since the casing system are delivered.