bhp & well kill iadc

7/21/2019 Bhp & Well Kill Iadc

1/32

1-Constant BHP Theory

Sparks Petroleum Services OmanSparks Petroleum Services Oman

Constant Bottom Hole PressureConstant Bottom Hole Pressure

TheoryTheory


2/32


ObjectiveObjective

Describe why constant bottom holeDescribe why constant bottom hole

pressure BHP! is re"uire#pressure BHP! is re"uire#

Demonstrate the a##itive e$$ects o$Demonstrate the a##itive e$$ects o$pressurepressure

Describe how to account $or $rictionDescribe how to account $or $riction

State the proce#ures use# to keep BHPState the proce#ures use# to keep BHPconstant or nearly constant!constant or nearly constant!


3/32

%-Constant BHP Theory

Why do we want constant BHP?Why do we want constant BHP?

Prevent a##itional in$lu&Prevent a##itional in$lu&

Provi#e basis $orProvi#e basis $or#etermination o$#etermination o$

pressures at other pointspressures at other points

in the wellin the well

Can be monitore# via DPCan be monitore# via DP

S'DPP

S'CP

'n$lu& stops

when BHP

becomes

e"ual to the

(ormation

Pressure

BHP ) Pore Pressure


4/32

*-Constant BHP Theory

Consider a Simplified WellConsider a Simplified Well

(ormation Pressure +, psi

S'CP

+,

Out o$ hole. kick #etecte#Out o$ hole. kick #etecte#

/ell shut-in/ell shut-in

'n$lu& $low rate be0ins to'n$lu& $low rate be0ins to

#ecrease#ecrease

/ellbore BHP an# pore/ellbore BHP an# pore

pressure e"ualiepressure e"ualie

/hat is S'CP/hat is S'CP


5/32

+-Constant BHP Theory

mposed SCP stops influ!mposed SCP stops influ!

Total 3u#Hy#rostatic

Pressure is

+ psi


S'CP

+,

S'CP

4

Total 3u# Hy#rostatic

Pressure o$ + psi

5"ualies the BHP

thus.

S'CP ) BHP - +

S'CP ) +, - +

S'CP ) , psi

) ,


6/32


Well Still Shut"inWell Still Shut"in

/hat happens as time passes/hat happens as time passesan# we #o nothin0 at allan# we #o nothin0 at all


7/32


#as $i%rates Half"way to Top#as $i%rates Half"way to Top


,%

3u# Hy#rostatic

Pressure is 2+ psi

3u# Hy#rostatic

Pressure is 2+ psi

8as Pressure is +, psi

/O/9

BHP ) 8as Pressure 4

Hy#rostatic o$ 3u# Below


8/32

,-Constant BHP Theory

Casin% Pressure &lso ncreasesCasin% Pressure &lso ncreases


%%

,%

3u# Hy#rostatic

Pressure is 2+ psi

3u# Hy#rostatic

Pressure is 2+ psi


/O/9

CP ) 8as Pressure less

Hy#rostatic o$ 3u# :bove


9/32

;-Constant BHP Theory

#as at the Suface#as at the Suface


+,

1.,

3u# Hy#rostatic

Pressure is + psi


BHP ) 8as Pressure plusHy#rostatic o$ 3u# Below

(ormation likely to $aillon0 be$ore this

pressure is reache#9


10/32


'et(s Start Over'et(s Start Over


11/32


Can we )eep BHP constant?Can we )eep BHP constant?

Total 3u#Hy#rostatic

Pressure is

+ psi


,

+,

=et>s start overs =aw

?eep the sum o$ 0as pressure?eep the sum o$ 0as pressure

plus the hy#rostatic o$ theplus the hy#rostatic o$ themu# below the 0as e"ual tomu# below the 0as e"ual to

the ori0inal BHP +, psi!the ori0inal BHP +, psi!


12/32


#as $i%rates Half"way to Top* BHP#as $i%rates Half"way to Top* BHP

Pressure +ept at ,-.. psiPressure +ept at ,-.. psi


+,

@pper mu# column hy#rostatic is

2+ psi

=ower mu# column hy#rostatic is

2% psi

8as e&pan#s as 2 bbls mu# is ble#.

0as pressure #ecreases to %+ psi 2 bbls ble#


13/32

1%-Constant BHP Theory

Casin% Pressure ncreases as $ud isCasin% Pressure ncreases as $ud is

Bled and BHP +ept at ,-.. psiBled and BHP +ept at ,-.. psi


1

+,

2 bbls ble#

CP ) 8as Pressure less

Hy#rostatic o$ 3u#

:bove

CP ) %+ - 2+

CP ) 1 psi


14/32

1*-Constant BHP Theory

#as at Surface as $ud is Bled and#as at Surface as $ud is Bled and

BHP +ept at ,-.. psiBHP +ept at ,-.. psi


16

+,

6 bbls ble#

8as Pressure ) 16 psi

CP ) 16 psi3u# Hy#rostatic ) *2

BHP ) +, psi


15/32

1+-Constant BHP Theory

BHP has been )ept at ,-.. psiBHP has been )ept at ,-.. psi


16

+,

6 bbls ble#

8as is at sur$ace

CP ) 16 psi

BHP ) +, psi

8reat


16/32


/se of the 0rill Pipe #a%e/se of the 0rill Pipe #a%e


,

+,

Pit 8ain

BHP ) +, psiCP ) , psi

Pit 8ain ) + bbls

Hy#rostatic in DP ) + psi

S'DPP ) BHP - DP Hy#rostatic

S'DPP ) +, - +%

S'DPP ) + psiS'DPP ) + psi

S'DPP'$ we have #rill pipe in the'$ we have #rill pipe in the

hole. we can use it as ahole. we can use it as a

link to the bottom


17/32


#as $i%rated Half"way#as $i%rated Half"way


1

+,

2 bbls

Ble#

BHP ) +, psi

Pit 8ain ) + bbls 4 2 bbls

S'DPP ) + psi

DP Hy#rostatic ) +% psi

BHP ) +4 +%BHP ) +4 +%

BHP ) +, psiBHP ) +, psi

+

Aow. as 0as mi0rates.Aow. as 0as mi0rates.

keep DP at + psi


18/32

1,-Constant BHP Theory

#as $i%rated to Surface#as $i%rated to Surface


16

+,

6 bbls

Ble#

BHP ) +, psi

Pit 8ain ) + bbls 4 6 bbls

S'DPP ) + psi

DP Hy#rostatic ) +% psi

BHP )+ 4 +%BHP )+ 4 +%


+

:s 0as mi0rates. keep:s 0as mi0rates. keep

DP at + psi< Blee#DP at + psi< Blee#

mu# as nee#e#


19/32

1;-Constant BHP Theory

12uivalent Hydraulic 0ia%ram12uivalent Hydraulic 0ia%ram

,

+,

Pit 8ain

+,

+,

Pit 8ain

+

=


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Balanced WellBalanced Well

+%

Pit 8ain

The hy#rostatic pressure inThe hy#rostatic pressure in

both columns are e"ual


21/32


Circulatin% 3riction " 'ow 4ateCirculatin% 3riction " 'ow 4ate

+%+

Pit 8ain

6+

Pumpin0 at 2 spmPumpin0 at 2 spm

Circulatin0 (riction ) 6+ psiCirculatin0 (riction ) 6+ psi

:nnular (riction ) + psi:nnular (riction ) + psi

BHP ) +% psi 4 + psiBHP ) +% psi 4 + psi

Pump

+

Consi#er the pressures whileConsi#er the pressures whilepumpin0 at a slow ratepumpin0 at a slow rate


22/32


+ic) in the Hole " Well Shut"in+ic) in the Hole " Well Shut"in

,

+,

+ bbls

+

/ell shut- in/ell shut- in

Pit 8ain ) + bblsPit 8ain ) + bbls

Aot yet circulatin0Aot yet circulatin0

Shut-in pressures recor#e#Shut-in pressures recor#e#

Pump


23/32

2%-Constant BHP Theory

Pump is Brou%ht to SpeedPump is Brou%ht to Speed

,

+,+

+ bbls

11+

Circulatin0 at 2 spmCirculatin0 at 2 spm

'nitial Circulatin0 Pressure )'nitial Circulatin0 Pressure )

'nitial Shut-in Pressure 4'nitial Shut-in Pressure 4

'nitial (riction Pressure'nitial (riction Pressure

3aintain 11+ psi on DP3aintain 11+ psi on DP

Pump

(500 +605)

+


24/32

2*-Constant BHP Theory

+ic) is /p the Hole+ic) is /p the Hole

1

+,+

11+


BHP constant because DPBHP constant because DP

pressure set at 11+ psipressure set at 11+ psi


CP increases because lessCP increases because less

mu# hy#rostatic in annulusmu# hy#rostatic in annulus

Pump

6+

+


25/32

2+-Constant BHP Theory

+ic) is at the Surface+ic) is at the Surface

16

+,+

11+


BHP constant because DPBHP constant because DP

pressure set at 11+ psipressure set at 11+ psi


CP has reache# a ma&imumCP has reache# a ma&imum

Pump

6+

+


26/32


Pump Balanced Wei%ht $udPump Balanced Wei%ht $ud

,

+,+

11+


'ntro#uce Balance# 3u#'ntro#uce Balance# 3u#

#ensity balances BHP!#ensity balances BHP!

/ill nee# to a#ust DPP as/ill nee# to a#ust DPP as#rill strin0 $ills with heavy#rill strin0 $ills with heavy

mu#mu#

Pump

6+

+


27/32


Balanced Wei%ht $ud Has 4eached BitBalanced Wei%ht $ud Has 4eached Bit

,+

+,+

66+


Drill strin0 $ull o$ heavy mu#Drill strin0 $ull o$ heavy mu#

DPP pressure re#uce# toDPP pressure re#uce# to

66+ psi. the $riction pressure66+ psi. the $riction pressureassociate# with the heavierassociate# with the heavier

mu#mu#

Pump

(1105 - 500) x MW2/MW1)

+


28/32

2,-Constant BHP Theory

+ic) to Surface+ic) to Surface

1%

+,+

66+


:nnulus partially $ille# with:nnulus partially $ille# with

heavy mu#heavy mu#

Casin0 pressure at ma& valueCasin0 pressure at ma& value

BHP still +,+ psiBHP still +,+ psi

Pump

66+

+


29/32

2;-Constant BHP Theory

#as is Out of Well#as is Out of Well

17+

+,+

66+


:nnulus contains two mu#s:nnulus contains two mu#s

Casin0 pressure re#uce#Casin0 pressure re#uce#


Pump

66+

+


30/32

%-Constant BHP Theory

Ori%inal $ud is Out of WellOri%inal $ud is Out of Well

+,+

66+


:nnulus contains balance#:nnulus contains balance#

wei0ht mu#wei0ht mu#

Casin0 pressure ) Casin0 pressure )

DPP ) (riction o$ new mu#DPP ) (riction o$ new mu#


Pump

66+

+


31/32

%1-Constant BHP Theory

Well is 0eadWell is 0ead

+,

Stop PumpsStop Pumps

/ell (ull o$ Balance# /t< 3u#/ell (ull o$ Balance# /t< 3u#

DPP ) DPP )

CP ) CP )


Pump


32/32

%2-Constant BHP Theory

SummarySummary

BHP or ) (ormation Pressure stops in$lu&BHP or ) (ormation Pressure stops in$lu&

DP 0a0e is link to BHPDP 0a0e is link to BHP

BHP can be kept constant i$ DP isBHP can be kept constant i$ DP is constant #urin0 circulation with ori0inal mu#constant #urin0 circulation with ori0inal mu#

constant a$ter balance# mu# reaches bitconstant a$ter balance# mu# reaches bit

a#uste# to account $or balance# mu# as it $ills DPa#uste# to account $or balance# mu# as it $ills DP

account $or hi0her #ensityaccount $or hi0her #ensity account $or hi0her $riction pressure in #rill strin0account $or hi0her $riction pressure in #rill strin0

bhp & well kill iadc

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