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Methods & Concepts
The Driller's Method
Well Control Methods applied on the drilling of the oil wells
The Driller's Method
During drilling operation of oil wells, there may be inflow of formation fluids into the well, which is an
undesirable condition. The driller should detect such events and closing the well immediately. Record
information after the closing of the well corresponding to stabilization of pressure, volume gain, SIDPP
(Shut-in Pressure Drillpipe) and SICP (Shut-in Casing Pressure. In the case of operations on floating units,
this term could be redefined as Shut-in Choke Pressure).
The control method to be applied is the driller's method. That is to circulate the influx even with the original
weight of the mud, keeping constant the circulation pressure named ICP - Initial Pressure Circulation. The
second circulation should be made with the kill mud weight in two steps: 1. Fill the drill string until the bit by
keeping the pressure on the kill line constant and equal to SIDPP. 2. Complete circulation of the annulus to the
surface keeping the pressure of circulation with the kill mud constant named FCP - Final Pressure Circulation.
Attention: about drill bit off bottom
This method should only be applied with the drill bit in the bottom hole or when the kick is completely in
annullus of the column. To minimize errors of calculation of the kill mud weight, the calculations made in this
application considers the depth of the drill bit instead of the depth of the well to calculate the kill mud weight.
The formation pressure consider the depth of well. In case of top of the kick bellow the bit, it is recommended
to apply the volumetric method until kick go through the drill bit to the annular, following then the driller's
method.
Formulas:
ICP = Pks + SIDPP
ICP - Inital Circulation Pressure, psi
Pks - Recorded pump pressure at the kill rate speed, psi
SIDPP - Shut-in Drillpipe Pressure, psi
Notes about floating units:
a) Pks must be recorded by circulating riser;
b) Record the friction loss in the choke line at the
kill rate speed, psi;
KM = OM + SIDPP / (0.052 x TVD)
KM - Kill Mud Weight, ppg
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OM - Original Mud Weight, ppg
TVD - True Vertical Depth, ft
FCP = Pks x KM / OM
FCP - Final Circulation Pressure, psi
Summary of method
STEPSPUMP
PRESSURE
KILL
PRESSURECHOKE PRESSURE
VOLUME TO
PUMP
Bring the pump to killspeed
- SICPSICP - Choke linefriction loss
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Circulate out the influx tosurface
ICP - - Annulus Volume
Circulate to fill drill stringwith kill mud
- SIDPPSIDPP - Choke linefriction loss
Drill stringvolume
Circulate to fill annulus withkill mud FCP - - Annulus Volume
Others formulas
Others formulas used in Driller's Method:
Example in Simulator
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