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Applications 
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Split
Flow Dart - SFD
|
Split
Flow Dart Overview -
Like the Standard diverter, the Split Flow Dart holds the valve
open with pumps off. Unlike the SDD the SFD has a choked bore
which allows pressure and flow to and from the bit.
For some applications full pressure relief is preferable, particularly
when moving in and out of hole. In addition the knowledge that there
is flow to bit can give better hole cleaning performance. The ability
to keep the BHA cool whilst agitating flow by spinning the pipe,
maximises hole-cleaning whilst and safe-guards expensive jewellry.
| SFD
Primary Applications |
|
- Hole
Cleaning
- Dry
Tripping
- BOP/Wellhead
Jetting
- Differential
Sticking
- Fluid/Mud
Displacement
- Pipe
Filling
|
|
|
(shown as cut-away to illustrate thru-bore) |
| Flow
control |
Pumps
on
|
Pumps
off
|
| Flow
to annulus |
Yes
|
Yes
|
| Flow
from annulus |
No
|
Yes
|
| Flow
to bit |
Yes
|
Yes
|
| Flow
from bit |
No
|
Yes
|
©
Copyright Churchill Drilling Tools 2011 |
| SFD
Data Sheet |
|
| Function
|
Opening |
| Length |
12" |
| Opening
shear resistance |
6,600
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 |
~66% |
| No.
of Cycles |
5* |
*When Standard 100" Catcher Deployed |
|
Case
History:
Pump out of hole, split flow
West Africa 2010
Full pressure relief whilst circulating
out of open hole was required by the formation conditions. The Split Flow
Dart allowed pumping out of hole (back to the 7” shoe) with split flow
hole cleaning. Simple drop and pump installation gave split flow rapidly
without any configuration complexity.
Conclusion: SFD is useful
alternative to the Standard Dart for end of run bypass
Case
History:
Pump out of hole and trip dry - multiple sections
Deepwater 2011
Optimised exits from long sections
in deepwater, illustrated the 'plug and play' utility of the Split Flow
Dart in both 12¼"
and 8½" sections.
Conclusion: Even in challenging
sections, the SFD can be delivered easily to activate split flow bypass.
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