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WDT Drop Off Casing System

Through years of experience and development in close coordination with drillers, Western Drilling Tools has developed the WDT Drop-Off Casing System. This casing advancement system is perhaps the most cost effective way to set single use casing. In addition to relatively low cost this is still a premium quality drilling tool capable of reaching astounding depths. It was designed to drill concentric holes for single use or retrievable casing. The drop off ring has a larger diameter than the casing. The guide device shoulders up to the casing shoe and the drop of ring is attached. Once coupled with a DTH hammer the driller slowly rotates the drill string and the guide device advances the casing. Once the required depth is met the driller rotates the drill string in the opposite direction dropping the ring in the hole and by applying tension allowing for the retrieval of the guide devices and the rest of the drill string. The drop off casing system is typically used in casing water wells, setting pilings and foundations for bridges and buildings, slant or horizontal drilling, environmental monitoring wells and grouting operations.
 
Advantages of the WDT DROP OFF SYSTEM

  • High rate of penetration means lower cost to the driller
  • Concentric drilling through any formation
  • Lots of standard and custom accessories
  • Made from high quality alloy steel
  • Easy bit changes
  • Simple design, one piece reamer and one piece guide device
  • Exceptional performance and ease of use
  • Excellent flushing and removal of cuttings
  • Compatible with most drill rigs
  • Made in North America to the highest quality standard

 

WDT Drop Off Casing System 

standard tool sizes

Casing Size

Wall Thickness

Size of Hole

inches

mm

nominal inches

max OD inches

max OD mm

inches

mm

inches

mm

2.76

70

3.0

3.50

88.9

0.216

5.5

3.75

95.3

3.15

80

3.5

4.00

101.6

0.266

6.8

4.88

123.9

3.54

90

4.0

4.50

114.3

0.237

6.0

5.00

127.0

4.53

115

5.0

5.63

142.9

0.258

6.6

6.13

155.6

5.51

140

6.0

6.63

168.3

0.280

7.1

7.50

190.5

6.49

165

7.0

7.63

193.7

0.301

7.6

8.75

222.3

7.48

190

8.0

8.63

219.1

0.322

8.2

9.75

247.7

8.27

210

9.0

9.63

244.5

0.342

8.7

11.00

279.5

8.46

215

9.5

10.00

254.1

0.500

12.7

11.15

283.3

9.45

240

10.0

10.75

273.1

0.365

9.3

11.33

287.7

 
For both casing drilling systems we recommend you use air pressure which does not exceed 210 PSI or 12 Bar. Remember that with most percussive or DTH hammer drilling methods you rely on rotation mostly to help clean the hole, not for significantly better rate of penetration. That said, slow down the rotation for larger diameter casing drilling tools and adjust the speed to suit what is appropriate for the formation you are drilling in.
 
Stratex System

Stratex System (mm)

Minimum Torque (ft/lb)

Speed (rpm)

70

570

20 – 40

80

600

90

663

115

1470

10 – 25

140

2200

165

2950

190

4000

215

4000

240

4000

280

7000

 
WDT Drop Off

WDT Drop Off (mm)

Minimum Torque (ft/lb)

Speed (rpm)

70

580

20 – 45

80

610

90

670

115

1485

8  –  25

140

2215

165

2985

190

4000

215

4000

240

4100

280

7000

Description

Through years of experience and development in close coordination with drillers, Western Drilling Tools has developed the WDT Drop-Off Casing System. This casing advancement system is perhaps the most cost effective way to set single use casing. In addition to relatively low cost this is still a premium quality drilling tool capable of reaching astounding depths. It was designed to drill concentric holes for single use or retrievable casing. The drop off ring has a larger diameter than the casing. The guide device shoulders up to the casing shoe and the drop of ring is attached. Once coupled with a DTH hammer the driller slowly rotates the drill string and the guide device advances the casing. Once the required depth is met the driller rotates the drill string in the opposite direction dropping the ring in the hole and by applying tension allowing for the retrieval of the guide devices and the rest of the drill string. The drop off casing system is typically used in casing water wells, setting pilings and foundations for bridges and buildings, slant or horizontal drilling, environmental monitoring wells and grouting operations.
 
Advantages of the WDT DROP OFF SYSTEM

  • High rate of penetration means lower cost to the driller
  • Concentric drilling through any formation
  • Lots of standard and custom accessories
  • Made from high quality alloy steel
  • Easy bit changes
  • Simple design, one piece reamer and one piece guide device
  • Exceptional performance and ease of use
  • Excellent flushing and removal of cuttings
  • Compatible with most drill rigs
  • Made in North America to the highest quality standard

 

WDT Drop Off Casing System 

standard tool sizes

Casing Size

Wall Thickness

Size of Hole

inches

mm

nominal inches

max OD inches

max OD mm

inches

mm

inches

mm

2.76

70

3.0

3.50

88.9

0.216

5.5

3.75

95.3

3.15

80

3.5

4.00

101.6

0.266

6.8

4.88

123.9

3.54

90

4.0

4.50

114.3

0.237

6.0

5.00

127.0

4.53

115

5.0

5.63

142.9

0.258

6.6

6.13

155.6

5.51

140

6.0

6.63

168.3

0.280

7.1

7.50

190.5

6.49

165

7.0

7.63

193.7

0.301

7.6

8.75

222.3

7.48

190

8.0

8.63

219.1

0.322

8.2

9.75

247.7

8.27

210

9.0

9.63

244.5

0.342

8.7

11.00

279.5

8.46

215

9.5

10.00

254.1

0.500

12.7

11.15

283.3

9.45

240

10.0

10.75

273.1

0.365

9.3

11.33

287.7

 
For both casing drilling systems we recommend you use air pressure which does not exceed 210 PSI or 12 Bar. Remember that with most percussive or DTH hammer drilling methods you rely on rotation mostly to help clean the hole, not for significantly better rate of penetration. That said, slow down the rotation for larger diameter casing drilling tools and adjust the speed to suit what is appropriate for the formation you are drilling in.
 
Stratex System

Stratex System (mm)

Minimum Torque (ft/lb)

Speed (rpm)

70

570

20 – 40

80

600

90

663

115

1470

10 – 25

140

2200

165

2950

190

4000

215

4000

240

4000

280

7000

 
WDT Drop Off

WDT Drop Off (mm)

Minimum Torque (ft/lb)

Speed (rpm)

70

580

20 – 45

80

610

90

670

115

1485

8  –  25

140

2215

165

2985

190

4000

215

4000

240

4100

280

7000

For more information and product availability, Contact Western Drilling Tools at 1.888.410.0826.

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