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Selection of the extended length
The drill depth (BT) is not equal to the extended length (B) of the Kelly bar. It is due to following parameters:
X: | Height of construction for rotary drive incl. cardanic joint and shock absorber on top of the rotary drive |
Y: | Length of the drilling tool |
Z: | Length of the casing drive adapter |
V: | Height of the casing oscillator |
Ascertainment of the relevant, extended length:
| | Example |
| Max. drilling depth (BT) | 25 m |
- | Length of the drilling tool (Y) | - 1.5 m |
+ | Construction height for the rotary drive incl. cardanic joint and shock absorber on top of the rotary drive (X) | +1 m |
+ | Length of the casing drive adapter (Z) | + 2 m |
+ | Length of the casing drive adapter (Z) | + 0.5 m |
= | Min. extended length | 27.0 m |
Here is provided that the pull down system of the rig could drive the bottom of the casing drive adapter to the upper face of the casing oscillator.
The min. extended length must round up to the next extended length specified in the list.
ATTENTION!
Transport length (A) must be smaller than the
"Hang-in-length" (C) of the rig.
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