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Eccentric drilling tools with casing tube

Assembly Code:
Casing tube outside dia.(mm):
Casing tube wall thickness(mm):
Max Reaming dia. D1(mm):
Pilot bit dia. D(mm):
Guide device D2 (mm):
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Technical data
■ Description
Eccentric drilling tools with casing tube are very popular in international water well and ore drilling. It is a downhole air hammer system designed to advance casing during drilling. Once the desired depth is reached, the eccentric bit can be removed, leaving the casing in place for sampling or installation. After drilling is complete, remove the casing for reuse.

Eccentric drilling tools with casing tube

Eccentric casing drilling bits are today's preferred method of drilling in difficult surface conditions, such as where there are boulders or loose formations. The overburden casing drilling bits is the most economical solution as its clever wing bit is retractable for the next hole. This is especially suitable for shallow holes, which is often the case in water well drilling, geothermal wells and shallow micro-piling work. EDS is ideal for consolidating short holes in overlays.

Eccentric casing drilling bits

Our eccentric overburden casing drilling bits are sold all over the world. Main markets: Brazil, Chile, Colombia, Uruguay, Australia, Ukraine, Russia, Norway, Turkey, the United States, Canada, Iran, Malaysia, Thailand, India, etc.

The component of eccentric system consists of pilot bits, reamer bits, guide device and casing shoe.

Eccentric system

Working principle of eccentric drilling tool with casing:
When drilling, the reaming drill bits rotate outward, widening the hole enough for the casing to slide down behind the reamer. When the desired depth is reached, the drill pipe will reverse the hole and the reamer bit will retract, allowing the entire drilling system to pass through the casing.

eccentric drilling tool with casing

Eccentric drilling tools with casing tube step-by-step:

reaming drill bits

1. When drilling, the PGZ reamer swings out and drills a hole wide enough for the casing tube to slide down behind the reamer.
2. When required depth is reached, the drill is reversed and the reamer swings in, allowing the bit to pass through the casing.

overburden drilling system

3. Casing tube is pulled out directly or fixed atthe bottom of the hole by means of cement grout or other agglutinant.
4. Drilling continues to the desired depth using conventional DTH equipment.

Eccentric drilling tools

■ Application
ODEX casing system, also named eccentric casing system, it is suitable for drilling water wells, geothermal wells, short mircopiles, medium mini-type grouting hole of building, diamond harbour project.

odex bit

■ Features
Eccentric overburden casing drilling bit is the most economical solutions because its ingenious reaming wing the bit is retrievable can be used at the next hole.

Eccentric overburden casing drilling bit manufacturer

Advantages of overburden drilling system:
1. Rapid removal of cuttings;
2. No use of drilling mud;
3. High penetration rate, especially in resistant rock formation (e.g. basalt);
4. Easy soil and groundwater sampling during drilling;
5. Possible to measure yield estimate at selected depth in the formation.
■ Technical data
Assembly Code Casing tube Max Reaming dia. D1(mm) Pilot bit dia.
Guide device
D2 (mm)
Shank style
Outside dia.(mm) Wall thickness
PGZ82-3.5-108/6 108 6 116 82 94 DHD3.5
PGZ90-3.5-114/6 114 6 123 90 100 DHD3.5
PGZ115-340-142/7 142 7 151 115 126 DHD340A
PGZ115-340-146/7.5 146 7.5 155 115 128 DHD340A
PGZ140-350-168/8 168 8 189 140 149 DHD350R
PGZ140-350-178/9 178 9 192 144 156 DHD350R
PGZ149-350-183/10 183 10 197 149 161 DHD350R
PGZ165-360-195/6.5 195 6.5 211 165 179 DHD360
PGZ180-360-219/12.5 219 12.5 232 179 191 DHD360
PGZ190-360-219/7 219 7 236 190 203 DHD360
PGZ230-380-273/11.5 273 11.5 286 228 247 DHD380
PGZ240-380-273/6.5 273 6.5 308 240 257 DHD380
1. All diameters as above are only our standard diameters, but other diameters are also available upon request.
2. The unit weight for each size is for reference only.
3. Face design, buttons shape, buttons configuration and flushing holes number must be confirmed when the order is confirmed.
4. Please be cautious when order some bigger diameter of button bits since some bigger diameters are oversized.
5. Other shanks bits are also available as per request.
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