control principles and procedures

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Control Principles andProcedures



INTRODUCTION

PROCEDURES FOR MAINTAINING CONTROL of an oil or gas well during workoer and

!o"#le$ion differ signifi!an$l% fro" drilling well

!on$rol #ro!edures& Al$'oug' $'e (asi!

#ressure #rin!i#les re"ain $'e sa"e) $'e

"anners of i"#le"en$a$ion ar% so grea$l% $'a$

$'e% gie $'e a##earan!e of (eing a differen$

su(*e!$& As a resul$) i$ (e!o"es ne!essar% $os$ud% seeral differen$ well !on$rol #ro!edures

de#ending on for"a$ion #ressures and

o#era$ing !ondi$ions&



INTRODUCTION

For"a$ion #ressure is defined as $'e #ressureof $'e fluid wi$'in $'e #ore s#a!es of $'e ro!k&

Nor"al #ressure is !onsidered $o (e e+ual $o

$'e '%dros$a$i! #ressure of a full !olu"n of

na$ie wa$er fro" $'e surfa!e $o $'e er$i!al

de#$' of in$eres$& A(nor"al #ressures are $'ose

no$ e+ual and generall% grea$er $'an nor"al&

Su(nor"al #ressures are a s#e!ial !ase ofa(nor"al #ressures and are less $'an nor"al&

Rou$ine o#era$ing !ondi$ions ne!essi$a$e

differen$ well !on$rol #ro!edures&



INTRODUCTION

T'e "os$ !o""on si$ua$ions are killing a#rodu!ing well and !on$rolling ki!ks $'a$ o!!ur

during $'e workoer& Fur$'er !ondi$ions $'a$

di!$a$e well !on$rol #ro!edures are $%#e of

!o"#le$ion) for"a$ion #ressure,s- e.#osed $o

$'e well(ore) and $'e reasons for i"#le"en$ing

a workoer o#era$ion& Man% fa!$ors "us$ (e

known (efore sele!$ing $'e #ro#er kill#ro!edure&



CONTENTS Causes of Kicks

Warning Signs of Kicks

Shutin Procedures

Responsi!ilities for Shutin

O!taining and Interpreting Pressures

"uidelines to Check for Trapped Pressure

Kill Weight #ud Calculations

Killing a Producing Well

Kill During Worko$er



Causes of Kicks

% kick is an undesira!le entr& of for'ation fluids

into casing or tu!ing(

Kicks occur as a result of for'ation pressures

e)ceeding *orko$er fluid h&drostatic pressures

and causing for'ation fluids +gas, oil, or salt*ater-to flo* into the *ell!ore( In al'ost all *orko$er

operations, the operator atte'pts to 'aintain a

h&drostatic pressure slightl& greater than the

for'ation pressure and thus pre$ent kicks( Onoccasion, ho*e$er, and for $arious reasons, the

for'ation pressure *ill e)ceed the 'ud pressure

and a kick *ill occur(



Causes of Kicks

Insufficient #ud Weight

I'proper .ole /illUp

S*a!!ing

Cut #ud



Causes of Kicks


Insuffi!ien$ "ud weig'$ is one of $'e #redo"inan$

!auses of ki!ks& In $'is !ase) a #er"ea(le /one is

e.#osed w'ile using a "ud weig'$ $'a$ e.er$s less

#ressure $'an $'e for"a$ion #ressure& As a resul$ of

$'is #ressure i"(alan!e) fluids (egin $o flow in$o $'e

well(ore and $'e ki!k o!!urs&



A !o""on sour!e for $'is $%#e of ki!k during

workoers is drilling $'roug' o(s$ru!$ions su!' as

sand (ridges or *unk in $'e $u(ing or !asing& Pressures

"a% (e found (elow $'e (ridge $'a$ are grea$er $'an

$'e '%dros$a$i! #ressure of $'e fluid a(oe $'e (ridge&

T'is si$ua$ion "a% (e!o"e diffi!ul$ $o !on$rol sin!e

0endswa##ing0 of $'e fluids "a% o!!ur& T'is will

in!rease $'e diffi!ul$% of !ir!ula$ing $'e ki!k un$il $'e

swa##ing is !o"#le$ed&

Causes of Kicks




/illing the hole i'properl& during trips is anotherdo'inant cause of kicks( %s the *ork string is

pulled out of the hole, the 'ud le$el falls !ecause

the *ork string steel has displaced so'e a'ountof 'ud( With the pipe no longer in the hole, the

'ud 'ust fall( The o$erall le$el *ill decrease and,

as a conse0uence, the h&drostatic pressure of the

'ud *ill also decrease(

The follo*ing e)a'ple illustrates the h&drostatic

reduction *hen the drill pipe is pulled fro' the

*ell(

Causes of Kicks I'proper .ole /illUp



E)a'ple 1(23 Calculate the h&drostatic pressure

reduction *hen pulling 24, 56ft stands of drill pipe

*ithout filling the hole(

.ole data3

Casing ID78(4 in(

Work string79 :;< in(, <(68 I!;ft

Capacit& and displace'ent data3

Work string capacit&74(448919 !!l;ft %nnular capacit& +9 :;< ) 8(4in(-74(42=28 !!l;ft

Work string displace'ent74(4469 !!l;ft

#ud *eight75(< ppg




Solution3

+2- What is the total fluid displaced !& 24 stands of

pipe>

24 stands ) 56 ft;stand ) 4(4469 !!l;ft ? 9(5:= !!l

+9- .o* 'an& feet does 9(5:= !!l fill>

%nnulus plus *ork string capacit& ? 4(42=28 @

4(448919 ? 4(4926 !!l;ft

9(5:= !!l; +4(4926 !!l;ft- ? 265(: ft +6- What pressure reduction *ould occur>

4(489 ) 5(< ppg ) 265(: ft ? :2(9 psi




It should !e o!$ious fro' this e)a'ple that it is necessar&

to fill the hole *ith 'ud periodicall& to a$oid sufficientl&

reducing the h&drostatic pressure and allo*ing a kick to

occur( Se$eral 'ethods can !e utiliAed to fill the hole, !ut

all 'ust !e a!le to 'easure the a'ount of 'ud re0uired

accuratel&( It is not satisfactor& under an& conditions to

allo* a centrifugal pu'p to fill the hole continuousl& B fro'

the suction pit since accurate 'ud $olu'e 'easure'ent isnot possi!le( The t*o 'ethods 'ost co''onl& used to

'onitor hole filiup are a trip tank and pu'p stroke

'easure'ent(




% trip tank is an& s'all tank *ith a cali!ration

de$ice that can !e used to 'onitor the $olu'e of

'ud entering the hole( The tank can !e placed at

so'e le$el e0ual to the pre$enter height in order

to allo* a gra$it& feed into the annulus, or acentrifugal pu'p could transfer 'ud to the

annulus *ith the o$erflo* returning to the trip

tank( The pri'ar& ad$antages of the trip tank arethat the hole re'ains full at all ti'es and an

accurate 'easure'ent of the 'ud entering the

hole is possi!le(




%nother 'ethod of keeping the hole full of 'ud is

periodicall& to fill the hole *ith a positi$e

displace'ent pu'p such as the 'ain rig pu'p( %

flo* line de$ice can !e installed that *ill 'easure

the pu'p strokes re0uired to fill the hole and *ill

auto'aticall& shut off the pu'p *hen the hole

!eco'es full( The follo*ing e)a'ple illustrates the

usage of the rig pu'p to fill the hole during a trip(




E)a'ple 1(93 Calculate the nu'!er of pu'p strokes re0uired

to fill the hole if 24 stands of pipe are pulled fro' the hole(Use the data fro' E)a'ple 1(2(

Data

Pu'p 7 Singleacting triple)

7 6in( liner, =in( stroke Output 7 4(4262 !!l;stroke

Solution3

+2- /ro' E)a'ple 1(2, 24 stands of pipe displace 9(5:=

!arrels( +9- .o* 'an& strokes *ill !e re0uired>

arrels 7 !arrels per stroke ?9(5:= !!l;+4(4262 !!l;stroke-? 222 strokes +per 24 stands-




Causes of Kicks S*a!!ing

S*a! pressures are created !& pulling the *ork

string fro' the !orehole( The s*a! pressure is a

negati$e pressure and reduces the effecti$e

h&drostatic pressure throughout the hole( If this

pressure reduction is large enough to lo*er the

effecti$e h&drostatic pressure to a $alue !elo* the

for'ation pressure, a potential kick situation has

de$eloped(




A"ong $'e aria(les !on$rolling swa( #ressures are

#i#e #ulling s#eed) "ud1 #ro#er$ies) 'ole

!onfigura$ion) and $'e effe!$ of large workoer $ools

su!' as s+uee/e $ools and #a!kers& Pulling s#eed is

$'e #ri"ar% aria(le $'a$ !an (e !on$rolled during $'e

$ri##ing #ro!ess& In order $o redu!e $'e swa(

#ressure) #ulling s#eed "us$ (e redu!ed&




I$ is i"#or$an$ $o re"e"(er $'a$ $'e swa(#ressure is added $o $'e #ressure redu!$ion

resul$ing fro" no$ kee#ing $'e 'ole full as $'e

#i#e is #ulled& In addi$ion) $'e swa( #ressure is

e.er$ed a$ eer% #oin$ $'roug'ou$ $'e o#en 'ole

(elow $'e work s$ring een $'oug' $'e drill

s$ring "a% (e inside $'e !asing&



Causes of Kicks Cut #ud

Gas !on$a"ina$ion will o!!asionall% !ause a ki!k

al$'oug' $'e o!!urren!e is rare& T'e "ud densi$%

redu!$ion is usuall% !aused (% for"a$ion fluids su!' as

gas en$ering $'e well(ore& As $'e gas is !ir!ula$ed $o

$'e surfa!e) i$ "a% e.#and and redu!e $'e oerall'%dros$a$i! #ressure $o a #oin$ suffi!ien$ $o allow a ki!k

$o o!!ur& Al$'oug' $'e "ud weig'$ is !u$ seerel% a$

$'e surfa!e) $'e $o$al '%dros$a$i! #ressure is no$redu!ed signifi!an$l% sin!e "os$ of $'e gas e.#ansion

o!!urs near $'e surfa!e and no$ a$ $'e (o$$o" of $'e

well&




% nu'!er of *arning signs and possi!le *arning

signs of kicks can !e o!ser$ed at the surface( It is

the responsi!ilit& of each cre* 'e'!er to

recogniAe and interpret these signs and to take the

proper actions *ith respect to his *ell control

duties( %lthough all of the signs do not positi$el&

identif& a kick, the& do I *arn of a potential kick

situation( Each *arning sign is identified here as

either pri'ar& or secondar& relati$e to its

i'portance in kick detection(




/lo* Rate Increase

/lo*ing Well With Pu'ps Off

Pressure Decrease and Stroke Increase

I'proper .ole /illup

String Weight Change

Cut #ud Weight

S f



Warning Signs of Kicks /lo* Rate Increase

An in!rease in $'e flow ra$e) leaing $'e well

w'ile #u"#ing a$ a !ons$an$ ra$e) is one of $'e

#ri"ar% ki!k indi!a$ors& T'e in!reased flow ra$eis in$er#re$ed $o "ean $'a$ $'e for"a$ion is

aiding $'e rig #u"#s in "oing $'e fluid u# $'e

annulus (% for!ing fluids in$o $'e well(ore&

,Pri"ar% indi!a$or-

W i Si f Ki k



Warning Signs of Kicks /lo*ing Well With Pu'ps Off

2'en $'e rig #u"#s are no$ "oing $'e "ud) a

!on$inued flow fro" $'e well indi!a$es $'a$ a ki!k

is in #rogress& An e.!e#$ion $o $'is o!!urs w'en$'e "ud in $'e drill #i#e is !onsidera(l% 'eaier

$'an $'a$ in $'e annulus) as in $'e !ase of a slug&

,Pri"ar% indi!a$or-



Warning Signs of Kicks Pressure Decrease and Stroke Increase

A #u"# #ressure !'ange "a% indi!a$e a ki!k& T'e ini$ial

en$r% of $'e ki!k fluids in$o $'e (ore'ole "a% !ause $'e

"ud $o flo!!ula$e and $e"#oraril% in!rease $'e #u"#

#ressure& As $'e flow !on$inues) $'e low3densi$% influ.

will dis#la!e $'e 'eaier workoer fluids and $'e #u"#

#ressure "a% (egin $o de!rease& As $'e fluid in $'e

annulus (e!o"es less dense) $'e "ud in $'e work s$ring

"a% $end $o fall and $'e #u"# s#eed "a% in!rease&

,Se!ondar% indi!a$or-



Warning Signs of Kicks Pressure Decrease and Stroke Increase

Man% o$'er #ro(le"s "a% e.'i(i$ $'ese sa"e

signs& A 'ole in $'e #i#e) !alled a was'ou$) will

!ause $'e #u"# #ressure $o de!rease) and a

$wis$3off of so"e #or$ion of $'e drill s$ring will

s'ow $'e sa"e signs& I$ is $'e #ro#er #ro!edure)

'oweer) $o !'e!k for a ki!k if $'ese signs are

o(sered&

W i Si f Ki k



Warning Signs of Kicks I'proper .ole /illup

2'en $'e work s$ring is #ulled ou$ of $'e well) $'e "ud

leel s'ould de!rease (% a olu"e e+uialen$ $o $'e

a"oun$ of s$eel re"oed& If $'e 'ole does no$ re+uired

$'e !al!ula$ed olu"e of "ud $o (ring) $'e "ud leel(a!k $o $'e surfa!e) i$ is assu"ed $'a$ a ki!k fluid 'as

en$ered $'e 'ole and re#la!ed $'e olu"e of $'e "issing

work s$ring& Een $'oug' gas or sal$wa$er 'as en$ered

$'e 'ole) $'e well "a% no$ flow un$il enoug' fluid 'as

en$ered $o redu!e $'e '%dros$a$i! #ressure $o an a"oun$

less $'an $'e for"a$ion #ressure& ,Pri"ar% indi!a$or-

W i Si f Ki k



Warning Signs of Kicks String Weight Change

T'e drilling fluid in $'e 'ole #roides a (uo%an$ effe!$ $o

$'e work s$ring and effe!$iel% redu!es $'e a!$ual #i#e

weig'$ $'a$ "us$ (e su##or$ed (% $'e derri!k& 4eaier

"uds 'ae a larger (uo%an$ for!e $'an less3dense "uds&

2'en a ki!k o!!urs and low densi$% for"a$ion fluids

(egin $o en$er $'e (ore'ole) $'e $o$al (uo%an$ for!e of $'e

"ud s%s$e" is redu!ed& As a resul$) $'e s$ring weig'$

o(sered a$ $'e surfa!e (egins $o in!rease& ,Se!ondar%

indi!a$or-

W i Si f Ki k



Warning Signs of Kicks Cut #ud Weight

Redu!ed "ud weig'$ o(sered a$ $'e flow line 'as

o!!asionall% !aused a ki!k $o o!!ur& So"e of $'e !auses

for $'e redu!ed "ud weig'$ are !ore olu"e !u$$ing)

!onne!$ion air) or aera$ed "ud $'a$ was !ir!ula$ed fro"

$'e #i$s and down $'e work s$ring& For$una$el%) $'e lower

"ud weig'$ due $o $'e !u$$ings effe!$ is found er% near

$'e surfa!e) generall% due $o gas e.#ansion) and does

no$ !u$ $'e densi$% of $'e "ud a##re!ia(l% down'ole&

Gas !u$$ing !an 'ae a er% s"all effe!$ on $'e

(o$$o"'ole '%dros$a$i! #ressure&

W i Si f Ki k



Warning Signs of Kicks Cut #ud Weight

An i"#or$an$ #oin$ $o re"e"(er a(ou$ gas

!u$$ing is $'a$ if $'e well does no$ ki!k as $'e gas

is !ir!ula$ed $o $'e surfa!e) $'ere is onl% a s"all

#ossi(ili$% $'a$ i$ will ki!k& Generall%) gas !u$$ing

onl% indi!a$es $'a$ a slug of gas 'as (een

#ene$ra$ed su!' as $ra##ed gas (elow a (ridge&

I$ does no$ ne!essaril% "ean $'a$ $'e "ud

weig'$ "us$ (e in!reased& ,Se!ondar% indi!a$or-



Shutin Procedures

When one or 'ore of the *arning signs of kicks

are o!ser$ed, steps should !e taken to shutin the

*ell( If there is an& dou!t as to *hether the *ell is

flo*ing, shut it in and check the pressures( %lso,

there is no difference !et*een a s'all flo* and a

fullflo*ing *ell !ecause !oth can $er& 0uickl&

turn into a F F!igFF !lo*out(



Shutin Procedures

So'e hesitation has !een e)pressed !& industr&

personnel a!out fracturing the *ell through the

perforations into adGacent for'ations and possi!l&

creating an underground !lo*out as a result of

shutting in the *ell *hen a kick occurs( If the *ell

is allo*ed to flo*, it *ill e$entuall& !eco'e

necessar& to shutin the *ell, at *hich ti'e the

possi!ilit& of fracturing the *ell *ill !e greater

than had the *ell !een shutin i''ediatel& after

the initial kick detection(



Shutin Procedures

There has !een considera!le discussion as

to the 'erits of the hard shutin $ersus the

soft shutin procedure( % hard shutin is one

in *hich the annular pre$enter+s- are closedi''ediatel& after the pu'ps are shut do*n(

During the soft shutin procedures, the

choke is opened prior to closing the

pre$enter, and then the choke is closed(



Shutin Procedures

The t*o pri'ar& argu'ents in fa$or of soft shutin

procedures are to a$oid a *aterha''er effect

due to stopping fluid flo* a!ruptl& and to pro$ide

an alternate 'eans of *ell control +lo* choke

pressure 'ethod- should the casing pressure!eco'e F Fe)cessi$eH( The *ater ha''er effect

has no pro$en su!stance( In addition, the lo*

choke pressure 'ethod has !een sho*n to !e an

unrelia!le procedure( The pri'ar& argu'entagainst the soft shutin procedures is that of a

continuous influ) *hile the procedures are

e)ecuted(



Shutin Procedures

/or these reasons, onl& the hard shutinprocedure *ill !e presented in this 'anual(Se$eral t&pes of hard shutin proceduresare applica!le for *ell control depending

upon the t&pe of rig in use and the acti$it&occurring *hen the kick is taken( ariationsof shutin procedures are3

Drilling or *orkingi''o!ile rig

Tripping7i''o!ile rig

Drilling or *orkingfloating rig

Tripping7floating rig

Sh t i P d



Shutin Procedures Drilling or Working I''o!ile Rig

So'e hesitation has !een e)pressed !& industr&

personnel a!out fracturing the *ell through the

perforations into adGacent for'ations and possi!l&

creating an underground !lo*out as a result of

shutting in the *ell *hen a kick occurs( If the *ell

is allo*ed to flo*, it *ill e$entuall& !eco'e

necessar& to shutin the *ell, at *hich ti'e the

possi!ilit& of fracturing the *ell *ill !e greater

than had the *ell !een shutin i''ediatel& after

the initial kick detection(

Sh t i P d




%n i''o!ile rig does not 'o$e during

nor'al drilling operations( So'e t&pes are

land and !arge rigs, Gackups, and platfor'

rigs(

Sh t i P d




Shutin procedures3

2( When a pri'ar& *arning sign of a kick has

!een o!ser$ed, i''ediatel& raise the kell& until

a tool Goint is a!o$e the rotar& ta!le(9( Stop the 'ud pu'ps(

6( Close the annular pre$enter(

1( Notif& the co'pan& personnel(

8( Read and record the shutin tu!ing pressure,

the shutin casing pressure, and the pit gain(

Sh t i P d




Raising the kell& is an i'portant procedure

for se$eral reasons( With the kell& out of

hole, the $al$e at the !otto' of the kell& can

!e closed if necessar&( In addition, theannular pre$enter 'e'!ers can attain a

'ore secure seal on pipe than on a kell&(

Sh t i P d



Shutin Procedures Tripping i''o!ile rig

% high percentage of *ell control pro!le's

occur *hen a trip is !eing 'ade( The kick

pro!le's 'a& !e co'pounded *hen the

rig cre* is preoccupied *ith the trip

'echanics and the& fail to see the initial*arning signs of the kick(

Sh t i P d




Shutin procedures3

2( When a pri'ar& *arning sign of a kick has !een

o!ser$ed, i''ediatel& set the top tool Goint on the

slips(

9( Install and 'ake up a fullopening, full& opened safet&$al$e in the *ork

6( Close the safet& $al$e and the annular pre$enter(


8( Pick up and 'ake up the kell&(=( Open the safet& $al$e(

:( Read and record the shutin tu!ing pressure, the shut

in casing pressure, andthe pit gain(

Sh t in Proced res




Installing a fullopening safet& $al$e instead of an inside

!lo*out pre$enter +float- $al$e is a pri'e consideration

!ecause of the ad$antages offered !& the fullopening

$al$e( If flo* is encountered up the *ork string as a resultof a trip kick, the full& opened, fullopening $al$e is

ph&sicall& easier to sta! on the pipe than a floatt&pe

inside !lo*out pre$enter $al$e *hich *ould auto'aticall&

close *hen the up*ard'o$ing fluid contacts the $al$e(

+%ssu'e that a 'anual lock float $al$e is not in use(-

Shut in Procedures




If *ireline *ork such as perforating or logging!eco'es necessar&, the full opening $al$e *ill

accept logging tools appro)i'atel& e0ual to its

inner dia'eter( The float $al$e 'a& prohi!it

*ireline *ork altogether( %fter the kick is shutin,

an inside !lo*out pre$enter float $al$e 'a& !e

sta!!ed on top of the full opening $al$e to allo*

stripping operations for the return to !otto'(

Shut in Procedures



Shutin Procedures Drilling or *orkingfloating rig

% floating rig is one that 'o$es during t nor'al

drilling operations( The pri'ar& t&pes of floating

$essels are se'isu!'ersi!les and drill ships(

There are se$eral differences in the shutin

procedures for floaters due to their tendenc& topro'ote *ork string 'o$e'ent e$en *ith a 'otion

co'pensator in operation and also due to the

place'ent of the !lo*out pre$enter stack on the

sea floor( To sol$e the pro!le' of possi!le $esseland *ork string 'o$e'ent and the resultant *ear

on the pre$enters, a tool Goint *ill !e lo*ered on

the closed pipe ra's and the string *eight hung

on these ra's(

Shut in Procedures




One pro!le' *ith a stack located a

considera!le distance fro' the rig floor is to

ensure that a tool Goint does not interfere

*ith the closing of the pre$enter ele'ents(

To a$oid this pro!le', a spacingout

procedure should !e e)ecuted prior to

taking a kick !& closing the ra's, slo*l&

lo*ering the drill string until a tool Goint

contacts the ra's, and recording the

position of the kell& at that point(

Shut in Procedures




Shutin procedures3

2( When a pri'ar& *arning sign of a kick has !een

o!ser$ed, i''ediatel& raise the kell& to the le$el

pre$iousl& designated during the spacing out procedure(

9( Stop the 'ud pu'ps(

6( Close the annular pre$enter(


8( Close the upper set of pipe ra's(

=( Reduce the h&draulic pressure on the annular pre$enter(:( Jo*er the drill pipe until the pipe is supported entirel&

!& the ra's(

<( Read and record the shutin tu!ing pressure, shutin

casing pressure, and the pit gain(

Shut in Procedures



Shutin Procedures Tripping7floating rig

T'e #ro!edures for ki!k !losure during $ri##ing on a

floa$er are a !o"(ina$ion of $'e floa$ing drilling#ro!edures and $'e i""o(ile rig $ri##ing #ro!edures&

Shutin procedures35& 2'en a #ri"ar% warning sign of a ki!k 'as (een o(sered)

i""edia$el% se$ $'e $o# $ool *oin$ on $'e sli#s&6& Ins$all and "ake u# a full3o#ening) full% o#ened safe$% ale in$'e work s$ring&

7& Close $'e safe$% ale and $'e annular #reen$er&

8& No$if% $'e !o"#an% #ersonnel&

9& Pi!k u# and "ake u# $'e kell%&:& Close $'e u##er se$ of #i#e ra"s&

;& Redu!e $'e '%drauli! #ressure on $'e annular #reen$er&

<& Lower $'e work s$ring un$il $'e #i#e is su##or$ed (% $'e ra"s&

=& Read and re!ord $'e s'u$3in $u(ing #ressure) s'u$3in !asing#ressure) and $'e #i$ gain&

Responsi!ilities for Shut in



Responsi!ilities for Shutin

Ea!' "e"(er of $'e !rew 'as differen$ res#onsi(ili$ies during

$'e arious s'u$3in #ro!edures&Floorhand (Roughneck)5& No$if% $'e driller if an% warning signs of ki!ks are o(sered&

6& Assis$ in ins$alling $'e full3o#ening safe$% ale if a $ri# is (eing "ade&

7& Ini$ia$e 'is well !on$rol res#onsi(ili$ies af$er $'e well is s'u$3in&

Derrickman5& No$if% $'e driller if an% warning signs of ki!ks are o(sered&

6& Ini$ia$e $'e well !on$rol res#onsi(ili$ies and (egin "ud "i.ing#re#ara$ions&

Driller 5& S'u$3in $'e well i""edia$el% if an% of $'e #ri"ar% warning signs of ki!ksare o(sered&

6& If a ki!k o!!urs w'ile "aking a $ri#) se$ $'e $o# $ool *oin$ on $'e sli#s anddire!$ $'e !rews in $'e ins$alla$ion of $'e safe$% ale #rior $o !losing $'e#reen$er&

7& No$if% all #ro#er !o"#an% #ersonnel&

J i f Kill P d



Jogic for Kill Procedures

Seeral aria(les !on$rol kill #ro!edures

for workoer o#era$ions& T'ese are $'e

well1s #resen$ flowing s$a$us ,i$ "a%

re+uire killing (efore reen$r% !an (e"ade-) $'e "agni$ude of $'e for"a$ion

#ressures $'a$ "us$ (e !on$rolled) and

s#e!ial !onsidera$ions su!' as for"a$ionfra!$ure #ressure or !asing (urs$&

J i f Kill P d




In addi$ion) !er$ain unknown aria(les

su!' as $u(ing 'oles) #a!ker leaks) and

sand (ridges "us$ (e ealua$ed wi$'

res#e!$ $o $'e !o"#li!a$ions $'e% !rea$eon an alread% diffi!ul$ #ro(le"& Af$er all

known and unknown aria(les are s$udied)

$'e kill #ro!edure !an (e deelo#ed for $'egien si$ua$ion&

J i f Kill P d




Nor'al /or'ation Pressure

A nor"al for"a$ion #ressure is e+ual $o $'e '%dros$a$i!

#ressure of a full !olu"n of na$ie wa$er& As a resul$)

"os$ for"a$ions !an (e !on$rolled wi$' a "ud s%s$e"

,fres'wa$er) sal$wa$er) gel "ud) e$!&- weig'ing fro"<&773=&> ##g& T'e (asi! logi! $o kill a nor"al #ressure

well) $'erefore) is $o s$and a !olu"n of $'e re+uired

densi$% fluid fro" $'e surfa!e $o $'e flowing /one&

A$$aining a full !olu"n of wa$er ,"ud- "a% (e done (%lu(ri!a$ing) (ull'eading) or (% !ir!ula$ing& Indiidual

well !'ara!$eris$i!s will de$er"ine $'e "os$ feasi(le

#ro!edure $o use&

J i f Kill P d




Su!nor'al /or'ation Pressure

Rou$ine #rodu!$ion o#era$ions generall% redu!e

$'e #ressure wi$'in $'e for"a$ion $o alues less

$'an nor"al& 2'en $'is si$ua$ion o!!urs) kill

fluid densi$ies "a% fall (elow <&773=&> ##g&

T'ese su(nor"al for"a$ion #ressures re+uire

s#e!ial !onsidera$ions rela$ie $o well !on$rol&

J i f Kill P d





A #ro(le" in'eren$ w'ile reworking su(nor"al #ressure /ones

wi$' !lear wa$er ,fres' or sal$wa$eris $'e loss of wa$er $o $'e

in$eral if an% #ressure oer(alan!e is "ain$ained& T'e slig'$

#ressure oer(alan!e) w'i!' is nor"all% used $o #reen$ ki!ks)

will for!e !lear workoer fluids $o en$er $'e #er"ea(le

#rodu!ing in$eral in an effor$ $o !rea$e a (alan!e& As a resul$)

an% swa((ing a!$ion (% $'e work s$ring will !ause $'e well $oflow and a ki!k $o o!!ur& T'is #ro(le" is no$ res$ri!$ed $o

su(nor"al /ones (u$ is of$en en!oun$ered wi$' nor"al #ressure

in$erals&

J i f Kill P d





Seeral solu$ions are aaila(le $o re"ed% $'e #ro(le"

of fluid loss $o an o#en /one& T'e "os$ feasi(le is $o

#lug $'e /one wi$' a "a$erial su!' as !al!iu"!ar(ona$e or #ol%"er $'a$ !an (e re"oed la$er ,Fig&

8&5-& Seeral #a!kaged #rodu!$s are aaila(le fro"

!o""er!ial su##liers for $'is #ur#ose& Af$er $'eworkoer is !o"#le$ed) $'e (ridging "a$erial !an (e

re"oed wi$' a!id or a !'e"i!al (reaker&

J i f Kill P d



Jogic for Kill Procedures Su!nor'al /or'ation Pressure

J i f Kill P d





Ano$'er $e!'ni+ue used $o isola$e low #ressure

in$erals is #la!e"en$ of a "e!'ani!al (ridge su!' as

a #a!ker& T'e #a!ker is #la!ed in $'e well a(oe $'e

o#en /one so $'a$ $'e workoer o#era$ions !an (e

!o"#le$ed& T'is #ro!edure is feasi(le onl% if $'e

workoer is designed $o alleia$e so"e #ro(le" a(oe

$'e #rodu!$ie in$eral and no$ $'e in$eral i$self& Af$er

$'e work is !o"#le$ed) $'e #a!ker is re"oed and $'e

well is again #u$ on #rodu!$ion&

J i f Kill P d





A #o#ular "is!on!e#$ion a(ou$ workoers and

!o"#le$ion of su(nor"al #ressure /ones is $'a$ $'e%

#ose no well !on$rol #ro(le"s sin!e $'e #rodu!$iein$eral 'as low #ressures& In fa!$) "os$ (lowou$s

o!!ur in nor"al or su(nor"al? #ressure /ones and no$

in a(nor"all% 'ig' #ressure wells& I$ is i"#or$an$)$'erefore) $o (e as !au$ious wi$' low for"a$ion

#ressures as wi$' an% o$'er in$eral&

J i f Kill P d




%!nor'al +.igh- Pressures Main$aining !on$rol of a well wi$' a(nor"al

for"a$ion #ressures re+uires addi$ional

#lanning& I$e"s $o !onsider are an ealua$ion ofs'u$3in #ressures) kill densi$% fluid re+uire"en$s)

and (urs$ #ressures of $'e !asing and $u(ing& In

addi$ion) !o"#le$ion $e!'ni+ues su!' as$u(ingless !o"#le$ions e"#lo%ed wi$' 'ig'3

#ressure /ones fur$'er !o"#li!a$e $'e #ro!ess&

O!t i i d I t ti P




T'e s'u$3in #ressures are re!orded on $'e work

s$ring and !asing during a !losed3in !ondi$ion&

Al$'oug' (o$' #ressures are i"#or$an$) $'e

work s$ring #ressure will (e used al"os$e.!lusiel% in killing $'e well& S'u$3in $u(ing

,work s$ring- #ressure is la(eled SITP and s'u$3

in !asing #ressure is a((reia$ed SICP& For $'ee+ua$ions w'i!' follow) assu"e $'a$ $'e $u(ing

or work s$ring does no$ !on$ain a floa$&





An i"#or$an$ (asi! #rin!i#le !an (e seen in Fig&

8&6& In $'is !ase) $'e for"a$ion #ressure ,@4P-is grea$er $'an $'e $u(ing '%dros$a$i! #ressure

(% an a"oun$ e+ual $o $'e SITP& T'is !an (e

e.#ressed as in E+ua$ion SITP B Tu(ing '%dros$a$i! #ressure

@o$$o"'ole for"a$ion #ressure

Likewise) $'e !asing #ressure !an (e used $oealua$e @4P&

SICP B Annular "ud B Annular influ.

@o$$o"'ole for"a$ion





I$ is usuall% diffi!ul$ $o de$er"ine $'e annular influ.

'%dros$a$i! #ressure in #ra!$i!al si$ua$ions& T'erefore)

E+& 8&6 is no$ field a##li!a(le& Fig& 8&6 !an illus$ra$e

ano$'er i"#or$an$ (asi! #rin!i#le& I$ was s'own $'a$

$'e #ressure on $'e $u(ing gauge was $'e a"oun$

ne!essar% $o (alan!e $'e $u(ing '%dros$a$i! #ressure

wi$' $'e #ressure of $'e gas in $'e sand a$ 56)>>> f$&

T'e laws of #'%si!s sa% $'a$ fluids $rael fro" areas of'ig' #ressure $o areas of lower #ressure and do no$

$rael (e$ween areas of e+ual #ressures&





T'erefore) if $'e $u(ing #ressure is !on$rolled in

su!' a "anner $'a$ $'e $o$al #ressure a$ $'e

'ole (o$$o" is slig'$l% grea$er $'an $'e

for"a$ion fluid #ressure) no addi$ional ki!kinflu. will en$er $'e well& T'e !on!e#$ is $'e

(asis of $'e !ons$an$ (o$$o"'ole #ressure

"e$'od of well !on$rol in w'i!' $'e #ressure a$$'e (o$$o" of $'e 'ole is "ain$ained !ons$an$

and a$ leas$ e+ual $o $'e for"a$ion #ressure&





Tra##ed #ressure !an !ause errors in in$er#re$ing $'e

s'u$3in #ressures& T'is $%#e of #ressure is defined as

an% #ressure re!orded on $'e $u(ing or !asing $'a$ is

"ore $'an $'e a"oun$ needed $o (alan!e $'e

(o$$o"'ole #ressure& Pressure !an (e $ra##ed in $'e

s%s$e" in seeral wa%s) (u$ $'e "os$ !o""on are gas

"igra$ing u# $'e annulus and $ending $o e.#and) or

!losing $'e well in (efore $'e "ud #u"#s 'ae +ui$running& If a #ressure reading !on$ains so"e a"oun$

of $ra##ed #ressure $'e !al!ula$ions $o kill $'e well will

(e in error&





2'en !'e!king for $ra##ed #ressure) (leed

fro" $'e !asing side onl T'e #ri"ar% !'oke isgenerall% lo!a$ed on $'e !asings) T'is aoids!on$a"ina$ion of $'e "ud ,or (rine wa$er- in $'ework s$ring , $u(ing- and $'e #ossi(ili$% of#lugging $'e *e$s of $'e (i$) !ir!ula$ing #or$) orsliding sleee&

Use $'e work s$ring #ressure as a guide sin!e i$

is a dire!$ (o$$o"'ole #ressure indi!a$or&@leed s"all a"oun$s ,58 $o 56- ((l of "ud a$a $i"e& Close $'e !'oke af$er (leeding and

o(sere $'e #ressure on $'e work s$ring&





Con$inue $o al$erna$e $'e (leeding and

su(se+uen$ #ressure o(sera$ion #ro!eduresas long as $'e s'u$3in work s$ring #ressure

!on$inues $o de!rease& 2'en $'e #ressure

!eases $o fall) s$o# (leeding and re!ord $'e $rueSITP and SICP&

If $'e SITP s'ould de!rease $o /ero during $'is

#ro!edure) !on$inue $o (leed and !'e!k#ressures on $'e !asing side as long as $'e

!asing #ressure de!reases& ,No$e T'is s$e#

will nor"all% no$ (e ne!essar%&-





T'e (asis for $'e #ro!edure lis$ed a(oe is $'a$

$ra##ed #ressure is "ore $'an $'e a"oun$

needed $o (alan!e $'e (o$$o"'ole #ressure

and i$ !an (e (led off wi$'ou$ allowing an%

addi$ional influ. in$o $'e well& 4oweer) af$er all

of $'e $ra##ed #ressure is (led off and if $'e

(leeding #ro!edure is !on$inued) "ore influ.will (e allowed in$o $'e well and $'e surfa!e

#ressures will (egin $o in!rease&





T'ese (leeding #ro!edures !an (e i"#le"en$eda$ an% $i"e& 4oweer) i$ is adisa(le $o !'e!k

for $ra##ed #ressure w'en $'e well is s'u$3inini$iall% and $o re!'e!k w'en $'e work s$ring is

dis#la!ed wi$' a !lean kill fluid if an% #ressure

re"ains on $'e work s$ring&





O!!asionall%) ki!k killing #ro!edures "us$ (e

i"#le"en$ed w'en a $u(ing floa$ ale is used&

Sin!e a floa$ ale #reen$s fluid and #ressure

"oe"en$ u# $'e work s$ring) $'ere will (e no

#ressure readings af$er $'e well is s'u$3in&

Seeral #ro!edures for de$er"ining $'e $u(ing

#ressure ,SITP- are aaila(le& Ea!' de#endson $'e a"oun$ of infor"a$ion known a$ $'e $i"e

$'a$ $'e ki!k o!!urs&





/ind SITP if Kill Rate is Kno*n

5& S'u$3in $'e well) re!ord $'e s'u$3in !asing #ressure ,SICP- ando($ain $'e kill ra$e ei$'er fro" $'e driller or $'e dail% $our re#or$&

6& Ins$ru!$ $'e driller $o s$ar$ $'e #u"#s and "ain$ain $'e #u"#ingra$e a$ $'e kill ra$e ,s$rokes-&

7& As $'e driller s$ar$s $'e #u"#s) use $'e !'oke $o regula$e $'e!asing #ressure a$ $'e sa"e #ressure $'a$ was originall%re!orded a$ $'e s'u$3in !ondi$ions&

8& Af$er $'e #u"#s are running a$ $'e kill ra$e wi$' $'e !asing#ressure #ro#erl% regula$ed a$ $'e s'u$3in #ressure) re!ord $'e

#ressure o(sered on $'e $u(ing w'ile #u"#ing& 9& S'u$ down $'e #u"#s and !lose $'e !'oke&

:& T'e s'u$3in $u(ing #ressure e+uals $'e $o$al #u"#ing #ressure"inus $'e kill ra$e #ressure) or SITP To$al Pressure 3 kill ra$e#ressure





/ind SITP if Kill Rate is Not Kno*n

5& S'u$3in $'e well&

6& Line u# a low3olu"e) 'ig'3#ressure re!i#ro!a$ing

#u"# on $'e s$and

7& S$ar$ #u"#ing and fill u# all of $'e lines&8& Graduall% in!rease $'e $or+ue on $'e #u"#s un$il

$'e #u"#s ini$iall% (egin $o "oe fluid down $'e

work s$ring&

9& T'e SITP is $'e a"oun$ of #ressure re+uired $o

ini$ia$e fluid "oe"en$) T'is is assu"ed $o (e $'e

a"oun$ needed $o oer!o"e $'e #ressure a!$ing

agains$ $'e (o$$o" side of $'e ale&





Su(se+uen$ $o $'e de$er"ina$ion of $'e s'u$3in

#ressures) !al!ula$ions "us$ (e "ade $o define

a fluid densi$% $'a$ will !rea$e a '%dros$a$i!

#ressure e+ual $o or grea$er $'an for"a$ion

#ressure& ill weig'$ "ud ,or (rine wa$eris

defined as $'e fluid densi$% ne!essar% $o

(alan!e (o$$o"'ole for"a$ion #ressure e.a!$l%&

I$ will #roide $'e re+uired !on$rolling #ressures

%e$ "ini"i/e $'e #ossi(ili$% of !asing (urs$ or

for"a$ion fra!$ure&





Cal!ula$ing re+uired kill "ud densi$ies uses an e+ua$ion

si"ilar $o $'a$ s'own in E+&2M ,SITP B T4P- . 5=&67De#$'

2'ere2M ill weig'$ "ud) ##g

SITP S'u$3in $u(ing #ressure) #si

De#$' True er$i!al de#$') f$

5=&67 Conersion !ons$an$) ##g#sif$

T4P Tu(ing '%dros$a$i! #ressure) #si2M @4P . 5=&67de#$'

2'ere

@4P @o$$o"'ole #ressure) #si





E+ua$ions is $'e "os$ dire!$ "e$'od if $'e

(o$$o"'ole #ressure is known& As !an (e seen

in E+&) an indire!$ !al!ula$ion of (o$$o"'ole

#ressure is "ade (efore 2M is de$er"ined&

Diffi!ul$ies "a% arise w'en using E+& if T4P

"us$ (e !al!ula$ed w'en arious densi$% fluids

e.is$ in $'e $u(ing& E.a"#les 8&7 and 8&8

illus$ra$e $'e !al!ula$ion #ro!edures for 2M

de$er"ina$ions&





E)a'ple 1(6

A well is #rodu!ing under $'e following!ondi$ions& If a workoer (e!o"es ne!essar%)w'a$ kill weig'$ fluid is re+uired

Data3Perfora$ions a$ 5>)69> f$ ,TD-

@4P 8);89 #si

Solu$ion2M @4P . 5=&67De#$'

8;89 #si . 5=&675>)69> f$

<&= ##g





E)a'ple 1(1

Cal!ula$e a kill fluid densi$% for workoer under $'e following!ondi$ions&

Data3Perforations at 22,=44 ft +TD-

SITP ? 6,584 psi

Specific "ra$it& ?4(=5 +oil in tu!ing-Solution3,5- Cal!ula$e T4P

T.P ? 4(489 ) <(66 ppg ) 4(=5 ) 22,=44 ft

? 6,1=: psi

,6- Use E+ua$ion 8&8 2M ,SITP B T4P- . 5=&67De#$'

,7)=9> #si B 7)8:; #si- . 5=&6755):>> f$

,;)85; #si- . 5=&6755):>> f$

56&6= ##g





/or'ation /racture Pressures

T'e (asi! logi! for "os$ well !on$rol si$ua$ions is

$o !ir!ula$e a full !olu"n of kill densi$% fluid& As

#reiousl% dis!ussed) $'is $e!'ni+ue !an (e

!o"#li!a$ed if a #er"ea(le for"a$ion ise.#osed& I$ will allow fluid flow in$o $'e fo"a$ion

if an oer(alan!e o!!urs& Fur$'er !o"#li!a$ions

!an arise if an undesira(le for"a$ion fra!$ure is!rea$ed $'a$ will allow a loss of workoer fluids

in$o ad*a!en$ for"a$ions&






T'is usuall% o!!urs w'en $'e fra!$ure #ressure of$'e for"a$ion 'as (een e.!eeded& For"a$ionfra!$ure #ressures de#end on de#$') ro!k $%#e)

and for"a$ion #ressure& Seeral au$'ors 'aes$udied $'ese aria(les and 'ae s'own $'a$s'ale se!$ions will generall% fra!$ure wi$'#ressures less $'an $'ose re+uired for sand

se!$ions& Al$'oug' "os$ !o"#le$ion #ra!$i!eswill a$$e"#$ $o isola$e $'e #rodu!ing in$eral fro"o$'er /ones) i$ s'ould (e assu"ed $'a$ a s"allse!$ion of s'ale is e.#osed&






As a resul$) $'e for"a$ion fra!$ure #ressure ,orgradien$- "us$ (e !al!ula$ed using s'ale as $'ero!k $%#e& T'is !onsera$ie a##roa!' %ields a

"ini"u" alue for #ossi(le fra!$ure #ressures&Cal!ula$ion #ro!edures for $'e de$er"ina$ion offra!$ure #ressure ,$er"ed fra!$ure gradien$ w'ene.#ressed in #sif$- generall% inole !o"#le.

e+ua$ions and gra#'s& 4oweer) a !'ar$ su!' asFig& 8&7 resoles $'ese !o"#le.i$ies in$o asi"#le) dire!$ solu$ion& E.a"#le 8&9 illus$ra$esuse of $'e !'ar$&




Kill Weight #ud Calculations /or'ation /racture Pressures






E)a'ple 1(8

A workoer is $o (e #erfor"ed on a well wi$'$'e !'ara!$eris$i!s des!ri(ed (elow& 2'a$

would (e $'e "ini"u" fra!$ure #ressure under$'e gien !ondi$ions In addi$ion) w'a$ s$a$i!$u(ing #ressure would fra!$ure $'e for"a$ion

Data3Perfora$ions a$ <):>> f$ ,TD-

For"a$ion #ressure Nor"al

Produ!ed fluid in $u(ing >&; s#e!ifi! grai$% oil






Solution3

,5- Using $'e Ea$on !'ar$) en$er on $'e er$i!al s!ale a$a de#$' of <):>>f$& Read on a 'ori/on$al line un$il $'enor"al #ressure ,=&> ##g- for"a$ion line isen!oun$ered& Fro" $'is in$erse!$ion) read er$i!all%un$il $'e fra!$ure #ressure of 5:&6 ##g is read&

,6- T'e fra!$ure #ressure in $er"s of #si is>&>96 . 5:&6 ##g . <):>> f$ ;)688 #si

SITP Fra!$ure #ressure 3 oil '%dros$a$i! #ressure

;)688 #si 3 ,>&>96 . >&; . <&77 ##g . <):>> f$-

;)688 3 6):>;

8):7; #si





The first step in *orko$er operations often

in$ol$es killing a *ell that is producing

h&drocar!ons( Nu'erous kill procedures are

a$aila!le depending on circu'stances such as

tu!ing and casing integrit&, a!ilit& to circulate thefluid in the annulus, for'ation pressure, and

characteristics of the co'pletion 'ethods and

for'ation para'eters that 'a& control techni0ues

such as re$erse pu'ping into the for'ation(

Indi$idual *ells 'ust !e e$aluated to deter'ine

the 'ost effecti$e procedure(





Entering the Well

Killing a Nor'alPressure Well

%nnulus Kill ProceduresKill *ith a .ole in the Tu!ing

Tu!ing Kill Procedures

%!nor'alPressure Producing Well




g g Entering the Well

Prior $o ini$ia$ing well !on$rol o#era$ions) seeral

safe$% #re!au$ions "us$ (e e.er!ised& Produ!$ion

!'okes and $'e "as$er ale are !losed $o 'al$ fluid

#rodu!$ion& T'e u##er swa( ale ,if #resen$- is

usuall% !losed $'us allowing workoer e+ui#"en$ $o (eflanged $o $'e $ree& T'is e+ui#"en$ !ould in!lude

lu(ri!a$ors for wireline or "e!'ani!al se$ #lugs) #u"#3

in lines) or @OP s$a!ks for !oil $u(ing or snu((ing

e+ui#"en$& Pro#erl% flanging $'e e+ui#"en$ $o $'e $reeis essen$ial for safe #ra!$i!es sin!e a lie well will

#ressuri/e $'e e+ui#"en$ as soon as $'e "as$er and

swa( ales are o#ened&




g g Entering the Well

@a!k3#ressure ales and #lugs) wireline) or

"e!'ani!al se$ are nor"all% e"#lo%ed w'ile rigging

u# surfa!e e+ui#"en$& A wireline #lug "a% (e se$ a$

5>> f$ down in $'e $u(ing) w'ile a "e!'ani!al (a!k3

#ressure ale is se$ in $'e (o$$o" of $'e $ree& T'ese$ools aid in #reen$ing (lowou$s in su!' !ases as

flange leak de$e!$ion w'ile #ressure $es$ing $'e $rees

and $ree da"age resul$ing fro" so"e a!!iden$o!!urring during $'e rigging u# o#era$ions&

I""edia$el% #rior $o ini$ia$ion of $'e kill #ro!edures)

$'ese ales and #lugs "a% (e re"oed&




g g Killing a Nor'alPressure Well

T%#e of fluids (eing #rodu!ed fro" $'e well) for"a$ion!'ara!$eris$i!s) $u(ing 'oles) and $'e !ondi$ion of $'e

#a!ker fluid in $'e annulus di!$a$e kill #ro!edures Mos$

!an (e !a$egori/ed in$o $'ose "e$'ods for killing

$u(ing wi$' and wi$'ou$ 'oles as well as for killing $'e

annulus& illing an a(nor"al3#ressure #rodu!ing well

will re+uire $'e sa"e !onsidera$ions as nor"al3

#ressure wells in addi$ion $o o$'er s#e!ial #ro(le"s&






T%#e of fluids (eing #rodu!ed fro" $'e well) for"a$ion

!'ara!$eris$i!s) $u(ing 'oles) and $'e !ondi$ion of $'e

#a!ker fluid in $'e annulus di!$a$e kill #ro!edures Mos$

!an (e !a$egori/ed in$o $'ose "e$'ods for killing

$u(ing wi$' and wi$'ou$ 'oles as well as for killing $'e

annulus& illing an a(nor"al3#ressure #rodu!ing well

will re+uire $'e sa"e !onsidera$ions as nor"al3

#ressure wells in addi$ion $o o$'er s#e!ial #ro(le"s&





Mos$ workoer o#era$ions will re+uire killing a

#rodu!ing well $'a$ does no$ 'ae a 'ole in $'e

$u(ing& T'e kill #ro!edures for $'is si$ua$ion

in!lude (ull'eading) snu( !oil $u(ing) snu(

*oin$ed $u(ing) lu(ri!a$ing #erfora$ing $'e $u(ing)

and #ulling $'e $u(ing ou$ of $'e #a!ker&






@ull'eading is a $er" used $o des!ri(e $'e #u"#ing of

fluids in$o $'e for"a$ion In $'e !ase of well !on$rol) $'e

o(*e!$ie is $o #u"# a workoer fluid down $'e $u(ing

and drie $'e for"a$ion fluids ou$ of $'e $u(ing)

$'roug' #erfora$ions and (a!k in$o $'e for"a$ions&

E.a"#le 8&: illus$ra$es a $%#i!al (ull'eading

#ro!edure&





Tu!ing Kill Procedures E)a'ple 1(= Using $'e da$a gien (elow) "ake $'e

ne!essar% !al!ula$ions and des!ri(e $'e s$e#s $o

(ull'ead $'e #rodu!ed fluids in$o $'e for"a$ion&

Data3

Perfora$ions a$ =)5>> f$

For"a$ion #ressure =&> ##g ,nor"al-

Fra!$ure gradien$ 5:&9 ##gT4P ;=9 #si

SITP 7)89; #si

Tu(ing 6%in&) N3<>) :&8 I(f$&





Tu!ing Kill Procedures Solution3

5& Cal!ula$e $'e re+uired surfa!e3i"#osed #ressures $o e.!eed$'e for"a$ion fra!$ure #ressures ,FP- FP ,INITIAL- H ,5:&9 ##g . >&>96 . =)5>> f$- 3 ;=9

;)>57 #si FP ,FINAL- ;)<>< #si 3 ,>&>96 . =&> ##g . =)5>> f$-

7)98= #si

6& Plo$ $'ese alues on Fig& 8&8

7& Cal!ula$e $u(ing !a#a!i$ies

=)5>> f$ . >&>>9;=8 ((lf$ 96&; ((l8& De$er"ine $'e $u(ing (urs$ #ressure and #lo$ on Fig& 8&8&

9& Slowl% (egin #u"#ing =&> ##g (rine wa$er down $'e $u(ing& Do no$e.!eed an% of $'e #ressures s'own on Fig& 8&8&

:& 2'ile #u"#ing) "oni$or $'e #ressures on $'e !asing and ad*a!en$ s$rings$o de$e!$ an% undesira(le #ressure (uildu#&





Tu!ing Kill Procedures Fig& 8&8 s'ows seeral i"#or$an$ #oin$s !on!erning(ull'eading& T'e s$a$i! #ressures on $'e gra#'indi!a$e $'a$ $'e re+uired (ull'ead #ressures s'ould

de!rease as in!reased olu"es of fluid are #u"#edin$o $'e $u(ing& If $'is o!!urren!e is no$ o(sered infield o#era$ions) ei$'er $'e for"a$ion1s a(ili$% $o a!!e#$fluid is de!reasing ,#lugging- or gas is "igra$ing

u#ward a$ a ra$e e+ual $o $'e downward #u"# ra$e& Inaddi$ion) $'e re+uired surfa!e3i"#osed fra!$ure#ressures de!rease as $'e low densi$% for"a$ion fluidsare dis#la!ed (% $'e grea$er3densi$% (rine fluids&






Gas "igra$ion "a% (e a serious #ro(le" in

workoer o#era$ions) #ar$i!ularl% w'en

(ull'eading $e!'ni+ues are used& Gas "igra$ion

is $'e u#ward "oe"en$ of low3densi$% fluids

$'roug' 'ig'er densi$% fluids& Fa!$ors affe!$ing"igra$ion ra$es in!lude rela$ie densi$ies and

is!osi$ies) 'ole geo"e$ries) and influ. si/e&





Tu!ing Kill Procedures In $'e !ases of for"a$ions wi$' !'ara!$eris$i!s $'a$

onl% allow low #u"#3in ra$es) u#ward gas "igra$ion

ra$es "a% e+ual or e.!eed $'e #u"# ra$es and resul$

in nega$ing $'e adan$ages of (ull'eading& A #ra!$i!al

field3#roen "e$'od !an offse$ $'e ill effe!$s of

"igra$ion& is!osifiers su!' as #ol%"ers are added $o

$'e workoer fluid& In!reased is!osi$% redu!es $'e

"igra$ion ra$e of $'e gas&





Tu!ing Kill Procedures In !er$ain !ases) (ull'eading will re+uire $'a$ so"e

#ressure is a##lied $o $'e !asing $o #reen$ $u(ing

(urs$& T'is $e!'ni+ue is generall% re+uired w'en $'e

#u"#3in #ressure is 'ig' or w'en $'e $u(ing in$egri$%

is +ues$iona(le due $o erosion or !orrosion& One

s'ould) 'oweer) de$er"ine $'e !asing (urs$ li"i$s $o

ensure $'a$ $'e% are no$ e.!eeded&





Tu!ing Kill Procedures For"a$ion fluid $%#es of$en affe!$ $'e feasi(ili$% of

a$$e"#$ing (ull'eading #ro!edures& Low is!osi$%

fluids su!' as gas will flow (a!k $'roug' $'e for"a$ion

a$ ra$es grea$er $'an oil or wa$er& In addi$ion) gas will

'ae a redu!ed $enden!% $o #lug $'e for"a$ion as i$

reerses flows& Cer$ain !o"#le$ion s%s$e"s su!' as

$u(ingless !o"#le$ions) 'oweer) "a% re+uire

(ull'eading ins$ead of so"e o$'er al$erna$ie&





Tu!ing Kill Procedures Coil $u(ing is of$en used $o kill a #rodu!ing well& T'e o(*e!$ie is

$o !ir!ula$e (rine wa$er down $'e s"all $u(ing and u# $'e !oil

$u(ing#rodu!$ion $u(ing annulus& A #ri"ar% a##li!a$ion for !oil

$u(ing is in !ases w'ere $'e well !anno$ (e killed (% (ull'eading(e!ause $'e well(ore is #lugged wi$' sand or *unk& Coil $u(ing

"a% (e res$ri!$ed in gas wells due $o s$reng$' li"i$a$ions of $'e

$u(ing& In so"e !ases) field e.#erien!e 'as s'own $'a$ a !oil

$u(ing se!$ion filled wi$' (rine wa$er will e.!eed $'e $ensiles$reng$' of $'e #i#e& T'is is no$ usuall% $'e !ase in oil wells

(e!ause $'e (uo%an!% #roided (% $'e oil redu!es $'e oerall

$u(ing load&





Tu!ing Kill Procedures Snu((ing uni$s are fre+uen$l% used for 'ig'3#ressure

well !on$rol #ro(le"s& Snu((ing s"all dia"e$er #i#e

in$o $u(ing #roides $'e sa"e $%#e of well !on$rol

#ro!edures as $'e !oil $u(ing wi$' $'e e.!e#$ion $'a$

"ore $i"e is re+uired $o snu( in *oin$ed #i#e $'an

!on$inuous !oiled $u(ing& T'e #ri"ar% adan$ages of

snu((ing uni$s oer !oil $u(ing are $'e a(ili$% $o ro$a$e

$'e *oin$ed #i#e and $'e grea$er #i#e s$reng$'&


Killing a Producing WellKilli N l P W ll



Tu!ing Kill Procedures Lu(ri!a$ion is o!!asionall% used for killing wells during

workoer o#era$ions& I$ is a #ro!ess $'a$ al$erna$el%

#u"#s a kill fluid in$o $'e $u(ing) and $'en a olu"e of

gas is allowed $o es!a#e fro" $'e well un$il $'e kill fluid

(egins $o es!a#e $'roug' $'e !'oke& A$ $'is #oin$)

(rine wa$er or o$'er fluids are #u"#ed in$o $'e $u(ing

and $'e !%!le is res$ar$ed&






As ea!' olu"e of (rine is #u"#ed in$o $'e

$u(ing) $'e SITP s'ould de!rease (% a

!al!ula$ed alue un$il $'e well is een$uall%

killed& Cau$ion "us$ (e e.er!ised so $'a$ large

olu"es of kill fluids are no$ allowed $o es!a#efro" $'e well during $'e (leeding #'ase&





Tu!ing Kill Procedures T'e lu(ri!a$e3and3(leed "e$'od is of$en e"#lo%ed for

$wo #ri"e reasons& Firs$) 'ig' #ressure wells $'a$

a##roa!' $'e ra$ed #ressure of $'e well'ead or $u(ing

"a% e.!eed $'e safe working li"i$s of $'e e+ui#"en$ ifin!reased d%na"i! #u"#ing #ressures are i"#osed

su!' as wi$' (ull'eading or snu((ing "e$'ods& T'e

lu(ri!a$ion "e$'od !an (e used ei$'er $o kill $'e well

!o"#le$el% or $o redu!e $'e s'u$3in #ressures $o a

leel $'a$ will allow safe o#era$ions of o$'er kill

"e$'ods&





Tu!ing Kill Procedures Ano$'er a##li!a$ion of $'e lu(ri!a$e3and3(leed "e$'od

is in wells $'a$ 'ae a #lugged well(ore or #erfora$ions

$'a$ will no$ allow (ull'eading& T'e lu(ri!a$ion#ro!edures !an (e e"#lo%ed $o kill $'e well wi$'ou$

$'e use of !oil $u(ing or *oin$ed !on!en$ri! kill s$rings&

Lu(ri!a$ion is of$en a $i"e3!onsu"ing #ro!ess& Ano$'er a##roa!' !ould !o"#le$e $'e kill "ore +ui!kl%&

E.a"#le 8&; illus$ra$es a $%#i!al lu(ri!a$e3and3(leed

"e$'od&





Tu!ing Kill Procedures E)a'ple 1(: A workoer is #lanned for a 'ig'3

#ressure well w'ere $'e s'u$3in #ressures a##roa!'

$'e ra$ed working #ressure of $'e well'ead e+ui#"en$&

To "ini"i/e $'e #ossi(ili$% of an e+ui#"en$ failure) $'e

lu(ri!a$e3and3(leed "e$'od will (e used $o redu!e $'e

s$a$i! #ressures $o a leel $'a$ will allow safe

(ull'eading





Tu!ing Kill Procedures Data3

2ell'ead #ressure ra$ing 9)>>> #si

SITP 8<>> #si

Tu(ing 6J3in&) N3<>) 8&; I(f$

Perfora$ions a$ 57);=9 f$

Solution3

5& Es$i"a$e $'e e.#e!$ed #ressure redu!$ion for ea!'(arrel of =&> ##g (rine #u"#ed in$o $'e well&

Tu(ing !a#a!i$% >&>>7<;> ((lf$

69<&8 f$((i ,565 #si((i-&





Tu!ing Kill Procedures 6& Rig u# all surfa!e e+ui#"en$ in!luding #u"#s and a gasflare line&

7& O#en $'e !'oke $o allow gas $o es!a#e fro" $'e well and"o"en$aril% redu!e $'e SITP&

8& Close $'e !'oke and #u"# in =&> ##g (rine un$il $'ed%na"i! $u(ing #ressure rea!'es 8)<>> #si&

9& 2ai$ $o allow $'e (rine $o fall in $'e $u(ing& T'e $i"e willrange fro" 58 $o 5 'our) de#ending on gas densi$%)#ressure) and $u(ing si/e&

:& O#en $'e !'oke and (leed gas un$il =&> ##g (egins $oes!a#e&

;& Close $'e !'oke and #u"# in =&> ##g (rine wa$er&

<& Con$inue $'e #ro!ess un$il a low) safe working #ressure isa$$ained& Fig& 8&9 illus$ra$es sa"#le resul$s&&


Killing a Producing WellKilling a Nor'al Press re Well





Killing a Producing WellKilling a Nor'al Pressure Well



Tu!ing Kill Procedures A !er$ain a"oun$ of $i"e is re+uired for $'e kill fluids $o

fall down $'e $u(ing af$er $'e #u"#ing !eases& T'e

a!$ual o!!urren!e is no$ (rine wa$er falling $'roug' $'e

gas (u$ ra$'er gas "igra$ing u#ward a$ 5;379 f$"in& As an e.a"#le) i$ would re+uire a !onsidera(le $i"e

lag for $'e fluid $o fall or "igra$e downward $o $'e

(o$$o" of a 5>)>>>3f$ well& T'erefore) af$er #u"#ing i$

is i"#or$an$ $o wai$ seeral "inu$es (efore (leeding

gas fro" $'e well $o #reen$ (leeding $'e kill fluid

$'roug' $'e !'oke&





Tu!ing Kill Procedures Perfora$ing $'e $u(ing and !ir!ula$ing a kill fluid is $'e

#ri"ar% "e$'od of killing #rodu!ing wells o$'er $'an

using inside3$u(ing kill #ro!edures& A #erfora$ing $ool

!an "ake a !ir!ula$ing #or$ in $'e $u(ing $'a$ will allowdire!$ !o""uni!a$ion wi$' (rine wa$er& In $'is si$ua$ion)

reerse !ir!ula$ion is usuall% done (% #u"#ing down

$'e annulus) $'roug' $'e #erfora$ion,s- and u# $'e

$u(ing& T'is "e$'od re+uires $'a$ $'e #a!ker fluid in

$'e annulus is in a !ir!ula$a(le !ondi$ion and no$

seerel% gelled or s$ra$ified&





Tu!ing Kill Procedures A$$en$ion "us$ (e gien $o $'e sele!$ion of a

#erfora$ion $ool& I$ is i"#era$ie $'a$ $'e $ool)

"e!'ani!al or o$'erwise) 'ae $'e !a#a(ili$% $o

#erfora$e $'e $u(ing wi$'ou$ da"aging $'e ad*a!en$

!asing ,es#e!iall% w'en $'e $u(ing is !lose $o $'e

!asing-& In addi$ion) orien$ed #erfora$ing is desired for

"ul$i#le !o"#le$ions w'i!' "a% 'ae seeral $u(ing

s$rings in $'e sa"e !asing annulus&





Tu!ing Kill Procedures Pulling $'e $u(ing ou$ of $'e #a!ker $o !ir!ula$e a kill

fluid ou$ of $'e (o$$o" of $'e $u(ing is a $e!'ni+ue

e"#lo%ed (% "an% o#era$ors& T'is #ro!edure inoles

lif$ing $'e $u(ing a suffi!ien$ 'eig'$ $o #ull $'e sealasse"(l% fro" $'e #olis'ed (ore in $'e #a!ker& T'e

disadan$age of $'is "e$'od is $'a$ i$ re+uires $'a$

se!$ions of $'e #rodu!$ion $ree (e re"oed or

unflanged $o #i!k u# $'e $u(ing& On!e $'e $ree is

unflanged) $'e "a*or (lowou$ #reen$ion $ool 'as (een

al$ered&





Tu!ing Kill Procedures Two $%#es of !o"#le$ions are no$ sui$a(le for $'is

"e$'od of well killing& Tu(ing s%s$e"s wi$' long

se!$ions of $'e seal asse"(l% !ould re+uire #i!king $'e

$u(ing s$ring u# 'ig'er $'an $'e workoer rig will allow&

Tu(ingless !o"#le$ions do no$ e"#lo% a #a!ker

s%s$e"& In $'ese !ases) $'e "e$'ods #reiousl%

des!ri(ed "us$ (e used&





Kill *ith a .ole in the Tu!ing

illing a #rodu!ing well $'a$ 'as a 'ole in $'e $u(ing or

a leak in $'e #a!ker re+uires addi$ional !onsidera$ions&

T'e #ri"ar% !on!ern is de$er"ining $'e lo!a$ion of $'e

'ole& Addi$ional !on!erns in!lude $'e effe!$ of $'e

for"a$ion #ressure e.#osed on $'e !asing and $'e kill

#ro!edure $'a$ will (e "os$ effe!$ie in ea!' !ase&





Kill *ith a .ole in the Tu!ing De$er"ining $'e lo!a$ion of $'e $u(ing 'ole generall%

re+uires an on3si$e ealua$ion of $'e si$ua$ion& T'e

'ole or leak will (e indi!a$ed (% #ressure on $'e

!asing s$ring,s-& T'e "os$ !o""on "e$'od of lo!a$ing

$'e leak is (% rigging surfa!e e+ui#"en$ and #u"#ing

a olu"e of (rine wa$er un$il i$ is re$urned $o $'e !'oke

on $'e annulus& T'is olu"e !an (e used $o !al!ula$e

$'e lo!a$ion of $'e 'ole&





Kill *ith a .ole in the Tu!ing E)a'ple 1(< A workoer was $o (e #erfor"ed $o

re#air a $u(ing s$ring $'a$ 'ad a leak& Af$er $'e

#u"#ing e+ui#"en$ was rigged u# on $'e well) a 7<3

(arrel olu"e of sal$wa$er was #u"#ed down $'e

$u(ing (efore i$ was de$e!$ed a$ $'e !'oke& Using $'e

da$a gien (elow) w'a$ was $'e de#$' of $'e 'ole in

$'e $u(ing


Killing a Producing Well Killing a Nor'alPressure Well



Kill *ith a .ole in the Tu!ingDa$a

Tu(ing 6i33in&) 8&; I(f$

Casing ;3in&) 67 I(f$

Tu(ing !a#a!i$% >&>>7<;> ((lf$ Annulus !a#a!i$% >&>77<< ((lf$

Solu$ionUsing $'e da$a gien a(oe) $'e 'ole lo!a$ion would (e

de$er"ined as followsolu"e #u"#ed!u(ing B annular- !a#a!i$% De#$' of 'ole

7< ((l,>&>>7<;> B >&>77<<- ((lf$ De#$'

7< ((l>&>7;;9 ((lf$ 5)>>: f$





Kill *ith a .ole in the Tu!ing Dee# 'oles !an generall% (e killed in a

!onen$ional !ir!ula$ion "anner& S'allow $o

"ediu"3de#$' 'oles will re+uire snu((ing !oil

$u(ing or *oin$ed #i#e or lu(ri!a$ion& @ull'eading

!an (e a$$e"#$ed onl% if $'e d%na"i! #ressuresdo no$ e.!eed $'e !asing (urs$ #ressures&&





%nnulus Kill Procedures A loss of in$egri$% in $'e $u(ing s$ring resul$ing

fro" a 'ole or leak will !ause a #ressure

(uildu# on $'e !asing or annulus& illing $'e

$u(ing (% lu(ri!a$ing or snu((ing will no$

ne!essaril% kill $'e annulus&





%nnulus Kill Procedures In $'is !ase) i$ is ne!essar% $o #erfor" a kill on

$'e annulus using one of $'e #reiousl%

des!ri(ed "e$'ods& T'ese in!lude (ull'eading)

lu(ri!a$ing) or reerse !ir!ula$ing& 2i$' $'ese

#ro!edures gas "igra$ion !an (e a serious#ro(le" w'en #u"#ing down $'e annulus&





%nnulus Kill Procedures arious o#era$ors 'ae used a se!ond s'or$ $u(ing

s$ring ,kill s$ring- for $'is a##li!a$ion& I$ is run as a dual

s$ring) (u$ i$ is no$ used as a flow s$ring& If #ressure

s'ould (uild u# on $'e !asing) kill fluid !an (e

!ir!ula$ed $'roug'ou$ $'e u##er se!$ions of $'e

annulus wi$'ou$ dis$ur(ing $'e flowing $u(ing s$ring&

ill s$rings are no$ e"#lo%ed in "os$ a##li!a$ions&


Killing a Producing Well %!nor'alPressure Producing Well



%!nor'al Pressure Producing Well

T'e !on!e#$s and #ro!edures for killing ana(nor"al3#ressure #rodu!ing well are

essen$iall% $'e sa"e as $'ose for a nor"al

#ressure well& T'e #ri"ar% e.!e#$ion is$'e use of 'ig'3densi$% kill fluids in #la!e

of =&> ##g (rine wa$er or o$'er fluids of low

densi$%& Cal!ula$ing $'e kill densi$%) as#reiousl% des!ri(ed) will s'ow $'e weig'$

needed&

Killing a Producing Well %!nor'alPressure Producing Well



%!nor'al Pressure Producing Well

T'e !on!e#$s and #ro!edures for killing ana(nor"al3#ressure #rodu!ing well are

essen$iall% $'e sa"e as $'ose for a nor"al

#ressure well& T'e #ri"ar% e.!e#$ion is$'e use of 'ig'3densi$% kill fluids in #la!e

of =&> ##g (rine wa$er or o$'er fluids of low

densi$%& Cal!ula$ing $'e kill densi$%) as#reiousl% des!ri(ed) will s'ow $'e weig'$

needed&

Kill During Worko$er



urst pressures of the tu!ular goods 'a&

!e a li'itation *ith highpressure *ells(

Tu!ing holes and leaks !eco'e a serious

concern !ecause the casing 'a& !e

e)posed to pressure( In addition, a!nor'al

pressure *ells often ha$e additional

pro!le's such as corrosion and erosion

that re0uire special consideration *hen

using tu!ular goods *ith lo* !urst

pressure ratings(

Kill During Worko$er Circulation Procedures



Circulation Procedures

When the *ork string is near the !otto' of the

*ell, circulating out the kick *ith a kill fluid is theapproach 'ost often used( The surface e0uip'ent

e'plo&ed in the procedure includes the pu'ps

and a choke to appl& a !ack pressure( The kill fluidis usuall& fresh or !rine *ater !ut *ill occasionall&

!e a *eighted fluid such as calciu' !ro'ide or

hea$& 'uds( The circulation route can !e do*n

the *ork string and up the annulus +the long *a&-,

or do*n the annulus and up the tu!ing+the short

*a&-(





Jong Circulation

The long or regular 'ethod of circulationin$ol$es pu'ping a kill fluid do*n thetu!ing or *ork string and up the annulus

*hile displacing the kick fluids during thecirculation( % si'ple sche'aticrepresentation is seen in /ig(1 = The pri'ar&ad$antage of this 'ethod is that kill

pressures are lo*er than those seen *hilekilling an identical kick *ith the re$erseoutprocedure( "as 'igration is not often ase$ere pro!le' *ith this procedure(





Jong Circulation





Jong Circulation

The re0uired kill fluid *ill !e of sufficient densit&to !alance he for'ation pressure at the !otto' ofthe *ell( This a'ount of 'ud *eight *ill kill the*el2 and 'ini'iAe the possi!ilit& of inducing afracture into the for'ation( The kill 'ud *eight is

deter'ined using an e0uation si'ilar to thatsho*n in E0(KW# ?? SITP ) 25(96;Depth

Where3KW# ? Kill *eight 'ud, ppg

SITP ? Shutin tu!ing +*ork string- pressure, psi Depth ? True $ertical depth, ft 25(96 ? Con$ersion constant, ppg;psi;ft





Jong Circulation

This e0uation is so'eti'es *ritten *ith theconstant 4(489 in the di$isor or +'ore properl&- !&25(98 in the nu'erator( The slight difference due torounding is inconse0uential in the field( Eithere0uation can !e used(

In 'ost cases, the kill fluid *ill !e 5(4 ppg !rine*ater or lo*er densities since for'ation pressuresgenerall& encountered are nor'al or lessthannor'al resulting fro' depletion( .igher kill 'ud

*eights are often re0uired as in the cases ofa!nor'al for'ation pressures or *here a *ell!oreo!struction pre$ents running the *ork string to!otto'(





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Circulating kill fluids *ill cause the pu'ping

pressures to change +/ig(1(:1(24-( The

causes for the changes include d&na'ic

pu'ping pressures, gas in the tu!ing,displacing lo*densit& *orko$er fluids *ith

highdensit& kill 'uds, and effects of the

choke restriction( /ig( 1(: and 1(5 illustratethe effect of pu'ping pressures added to

static shutin pressures(




C cu at o ocedu es

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Kill procedure re0uires 'aintaining the

pu'ping pressure at the designated le$els,

such as in /igs( 1(: and 1(5( The constant

!otto'hole pressure 'ethod uses pu'ppressure to control the !otto'hole pressure

at a $alue slightl& greater than for'ation

pressure( The choke is used to raise orlo*er the pu'ping pressure to the desired

$alue(




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If highdensit& kill fluid is re0uired to kill the

kick, a kill sheet 'a& !e an aid in

deter'ining the proper a'ounts of pressure

to 'aintain on the pu'p( The kill sheethelps calculate kill fluid densities and

e)pected pressure changes on the pu'ping

pressures( It contains other ite's such as*ork string $olu'es( % sa'ple kill sheet is

sho*n in /ig( 1(22(




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The annulus pressure *ill e)perience 'an&

changes during the course of the kick

killing procedures( The changes result fro'

gas e)pansion, gas 'igration, chokechanges, and high kill 'ud *eights *hen

used( It should !e noted that the pri'ar&

o!Gecti$e during kick killing is 'aintainingthe re0uired pu'ping pressures !&

adGusting the casing pressure as necessar&(




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Short +Re$erse- Circulation

Re$erse circulation in$ol$es pu'ping killfluids do*n the annulus and displacing thekick fluids up the tu!ing( % t&pical sche'atic

representation is sho*n in /ig( 1(26( Thisprocedure re0uires that a choke !e placed inthe standpipe or that the surface e0uip'entcan !e arranged in such a 'anner that kick

fluids are conducted through the standpipeto the choke( The choke 'anifold sho*n inChapter 6 allo*s nor'al and re$ersecirculation procedures(





Re$erse circulation ad$antages include a

significant reduction in the ti'e re0uired to

circulate the kick fluid fro' the *ell and!etter control of high surface pressures due

to the generall& greater !urst strength of

tu!ing and *ork strings as co'pared to

casing(





The disad$antages of re$erse circulation

include possi!le plugging *hen atte'pting

to re$erse flo* if !it Gets or circulating portsare in the *ork string( The slo* circulating

rates used in the re$erse procedure 'a&

allo* gas to 'igrate up the annulus at a rategreater than the do*n*ard flo* rate(





The re$erse circulation 'ethod utiliAes the

pu'ping casing pressure to 'onitor the kill

operation( The standpipe choke is used toadGust the pu'ping casing pressure to the

re0uired $alues( T&pical casing and *ork

string pressures are sho*n in /igure 1(21for the re$erse circulation procedure(





The gas 'igration pro!le', *hich 'a& !ese$ere in the re$erse 'ethod, 'ust !econsidered in deter'ining the application of

the 'ethod( These rates 'a& range fro' 64ft;'in in the case of gas 'igrating throughfresh *ater to as lo* as 9 ft;'in +or less- inhea$& $iscous 'uds( "as 'igration can !e

controlled !& increasing the pu'ping rate or!& adding to the kill fluid a $iscosifier *hich*ill decrease the up*ard flo* rate of thegas(




Worko$er Well Control Pro!le's

The pri'ar& causes for *orko$er pro!le's

are that kno*n producing inter$als are

e)posed to the *ell!ore and that *orko$erfluids generall& consist of onl& clean !rine

*ater( These !rines ha$e lo* $iscosities

*hich 'a)i'iAe gas 'igration rates and'ini'iAe *all!uilding fluid loss control

characteristics(





Well *orko$ers on lo*pressure per'ea!le Aones'ust contend *ith fluid loss or seepage( This 'a&

create a *ell control pro!le' if a sufficient $olu'e

of fluid is lost( This 'ight reduce the h&drostaticpressure and allo* a kick to occur( The 'ost

co''on 'ethod to reduce seepage and pre$ent

kicks is using a for'ation plugging 'aterial such

as $iscous pol&'er pills or calciu' car!onate(

%fter the *orko$er is co'pleted, the plugging

agents are re'o$ed !& !ackflo* or acidiAing(





et*eeninter$al flo*s often occur during

*orko$ers *hen high and lo* pressure

Aones are e)posed in the *ell!ore( The lo*

pressure Aones *ill not support a high

densit& kill fluid necessar& to control the

other inter$al( Re'edies to this pro!le'

include pol&'er plugging or calciu'

control principles and procedures

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