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Dart™ Performance
MX™
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Well
Control Dart - WCD
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Well
Control Dart Overview
- The
Well Control Dart is a unique feature of the DAV MX™ system.
Other
systems may close with the pumps off, but only the WCD latches
down and seals so that there is no flow path into the drill string
from either the bit or the annulus.
To
get full well control, sealing is necessary from the outside-in
and uniquely, for a simple valve, the DAV MX™ delivers.
Similar
in many ways to the SDD with its 100% bypass, the WCD is the ideal
dart for bypass in safety critical situations.
| WCD
Primary Applications |
|
- Bypass
with well control
- Spotting
LCM
- Hole
Cleaning
- BOP/Wellhead
Jetting
- Fluid/Mud
Displacement
- Pack-Offs
- Riser
Boosting
|
|
|
 |
| Flow
control |
Pumps
on
|
Pumps
off
|
| Flow
to annulus |
Yes
|
Yes*
|
| Flow
from annulus |
No
|
No
|
| Flow
to bit |
No
|
No
|
| Flow
from bit |
No
|
No
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* If there
is adequate differential pressure
©
Copyright Churchill Drilling Tools 2011
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| WCD
Data Sheet |
|
| Function
|
Opening |
| Length |
8" |
| Opening
shear resistance |
20,000
psi |
| Closing
shear yield |
2,000
psi |
| Rec'd
Opening Speed |
250gpm/6bpm |
| Maximum
Opening Speed |
350gpm/8bpm |
| Max.
Freefall Angle (@
zero gpm) |
55° |
| Bypass
TFA Ratio |
100% |
| No.
of Cycles |
6* |
*When Standard 100" Catcher Deployed |
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Case
History:
Circulate Bottoms Up in Reservoir
North Sea 2011
In a challenging well drilled off one
of the North Sea's oldest platforms, the spotlight had fallen on well-control
as being a primary issue. At the same time it was also clear that hole-cleaning
performance needed boosting. In the event the Well Control Dart delivered
time savings of at least 50% and a clean exit from hole.
Conclusion: WCD still delivers bypass even when safety is the ultimate
priority
Case
History:
Multiple Loss
interval curing
North Sea 2010
Originally specified to save time by
jetting on exit from hole, the WCD came into play as unexpected loss
zones were encountered. Multiple pills were spotted, drilling ahead
after curing by closing the tool. On successful completion of the section,
jetting was implemented as planned.
Conclusion: WCD demonstrates its capability for multiple LCM spotting
cycles.
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