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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

-

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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