DD Presentation on Limits

8/9/2019 DD Presentation on Limits

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Analytical

ModelingObject Reservoir

Limits


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WHAT WE KNOW ABOUT FLOW GEOMETRY:

-- Horizontal Well -- Multiple Fractures -- Fractures extend out ro! "ellbore

-- Fractures !ore or less e#ually spaced $but not a critical actor%

& ' ( & R ) A *

+ O * , M &

& ' ( & R ) A *

+ O * , M &

)o Flo"oundary

+irgin .ressure

Xf

Defning Flow Geometry

Fractured area around "ellboreis called t/e0

Stimulated Reservoir Volume(SRV)

,nractured area bet"een "ellsis called t/e0

External Volume (XRV)

SRV


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122

1222

12222

Gas Rate (MCF/d)

*inear

(rans ient

Flo" ro!

t/e 3R+

*inear

4epletion

Flo" ro!

t/e 3R+

*inear

transient

Flo"

&xternal

+olu!e

*inear

4epletion Flo"

ro! &xternal

+olu!e

Defning Flow Regimes

WHAT WE KNOW ABOUT FLOWREGMES:

• &arly ti!e data predo!inatelylinear 5o" into ractures in 3R+

• W/en transient reac/es t/e no-

5o" boundary bet"eenractures t/e "ell ex/ibitslinear depletion 5o" ro! t/e3R+

• As 3R+ depletes6 'R+ begins toex/ibit linear 5o" into 3R+

• W/en transient reac/es no-5o"boundary bet"een "ells t/e"ell ex/ibits linear depletion5o" in t/e 'R+


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L!"ea# T#a"s!e"t F$%&E'(at!%"

(Constant Pressure)

"/ere

9 slope o1:; vs<

"/ere

9.roductivity =ndex

t/ereore

inear !ransient Flow E"uationsConstant Pressure

>&? .O=)(0

For a "ell

producing at a

constant pressure6

t/e plot o vs<

yields a straig/t

line or linear

transient 5o" in

"/ic/ t/e slope

yields t/e value o


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#d$usting %or Varia&le 'P

)ROBLEM:Most "ells do not

produce at aconstantpressure


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#d$usting %or Varia&le 'PSuer Position !ime Funtion

SOLUTON:3uper-positiondata or variable 'P vs*

B !


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+nternal inear !ransient Flow

=n linear transient5o"6 t/e slope o

t/e Reciprocal.roductivity =ndexvs< 3uper .osition

(i!e "ill beconstant and

proportional to A

(/e ? interceptrepresents t/e

cu!ulative pressuredrop o all actors ot/er

t/an reservoirresistance to 5o" $D%<

(/is includes sDin6 Eniteconducting ractures6

"ellbore loading6 etc<


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Fro! t/e slope ot/e grap/ "e cancalculateG

and also t/eo!pletionResistance $yintercept%

+nternal inear !ransient FlowCalulating #, -./


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+nternal inear !ransient FlowSetting imits

)o" "e Dno" AD1:2< ut"e do not Dno" A or Dindividually< (/e nextstep is to set li!its on A

and D< Here is "/at "edo Dno"G

• A!ount o .roppant .u!ped

• )u!ber o per lusters

• .erorated *ateral lengt/

+ t l i ! i t Fl


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+nternal inear !ransient FlowSetting imits %or !otal Frature #rea (#) 0 Proant

Conentration

We can place reasonable!ini!u!6 !axi!u! and!ost liDely li!its on t/eproppant density $a proxyor racture t/icDness%based on experience and

racture stress !odels


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+nternal inear !ransient FlowSetting imits %or !otal %rature #rea (#) 0 Proant Plaement

E1ieny

.roppant .lace!ent&Jciency is t/e a!ount oproppant t/at actuallycontributes to racture

conductivity< We can placereasonable !ini!u!6!axi!u! and !ost liDelyli!its on t/e proppantplace!ent eJciency basedon experience andesti!ates ro! 4si!ulation<

+ t l i ! i t Fl


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+nternal inear !ransient FlowSetting imits %or !otal Frature #rea (#) 2 Cluster Prodution

E1ieny

luster .roduction&Jciency is t/eassu!ed percentageo clusters t/atproduce ater

racturing< Allclusters are assu!edto taDe an e#uala!ount o proppantbut only t/epercentage oclusters li!ited /ereare assu!ed toproduce aterracture<

+ t l i ! i t Fl


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+nternal inear !ransient FlowSetting imits %or !otal Frature #rea (#) 0 Calulated Values 0

Fratures

Assu!ed *i!its0• Avg< .rop onc< $4%• .rop< .lace< &K< $&%• luster .rod< &K< $c%

Ot/er >no"ns0•

Frac Heig/t $/% 172 t<• )u!ber o lusters $% 2• .roppant Mass $M%


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+nternal inear !ransient FlowSettin imits %or !otal Frature #rea (#) 0 Calulated Values 0 G+P

Ot/er >no"ns0• =nit< H. 7 psi• Res< (e!p< 1@ F• Nas Nravity


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Re< 3.& 11CC2

G+P Calulations in 3R4# imits

! t t % #d & d G i


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Re< 3.& 11CC2

!reatment o% #dsor&ed Gas inimits


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+nternal inear !ransient FlowSetting imits %or ,

(/e !ini!u! and!axi!u! D s/ould besuc/ t/at allreasonably possible Dvalues are insidet/ese t"o values<

(/e !ost liDely D isexactly t/at6 t/e apriori !ost liDelyvalue or D<


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+nternal inear transient FlowSetting imits %or , and #

Assu!edMaxi!u!

DAssu!ed Mini!u! Area

* i ne r epr esent i ng al l possi bl e c o!bi nat i ons o A and D " i t /i n t /e assu!ed

l i !i t s o A and D gi v en t /e c al c ul at ed v al ue o AD 1 : 2 r o! t /e sl ope o t /e super posi t i on t i !e

pl ot


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W/at is linear depletion5o"Q

W/en do "e enter lineardepletion 5o"Q

W/at can "e learn ro!linear depletion 5o"Q

+nternal inear Deletion Flow

122

1222

12222

Gas Rate (MCF/d)

*inear

(rans ient

Flo" ro!

t/e 3R+

*inear

4epletion

Flo" ro!

t/e 3R+

*ineartransient

Flo"

&xternal

+olu!e

*inear

4epletion Flo"

ro! &xternal

+olu!e


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& ' ( & R ) A *

+ O * ,

M &

& ' ( & R ) A *

+ O * ,

M &

)o Flo"oundary

.ressure4epletionAround Fracture

*i!it o 3R+

+irgin .ressure4irectio

n oFlo"

Xf

We$$ S*a+!",

.ressure (ransient 5#Sreac/ed t/e no-5o" boundariesbet"een racs

+nternal inear Deletion Flow67at is inear Deletion Flow8

l i l i l


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+nternal inear Deletion Flow67en do we enter linear deletion 9ow8

Once "e enter*inear 4epletionFlo"6 t/e slope ot/e =nverse .= vs<3.( plot "ill deviatero! linear curvingup"ard<

l i l i l


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+nternal inear Deletion Flow67en an we learn %rom inear Deletion Flow8

*S in t/e above e#uation is t/e distancero! t/e racture ace to t/e no-5o"boundary bet"een adjacent ractures $1:2t/e distance bet"een ractures%< (/e

point t/at t/e "ell transitions ro!transient to depletion 5o" represents t/epoint in ti!e "/en t/e transient /astravelled t/e distance *< We /avepreviously deter!ined t/e relations/ip oA and D ro! t/e transient 5o"< Once "eset t/e ti!e associated "it/ t/e end o

transient 5o" "e can no" bring * into t/ee#uation< (/us or a given D "e can no"calculate t/e corresponding * to Et t/eobserved data< Wit/ A and ** Exed6 "ecan no" calculate t/e corresponding 'and /ence t/e volu!e o t/e 3R+<

+ l i D l i Fl


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+nternal inear Deletion FlowDetermining Frature Saing

ased on t/edeter!ination o *6 t/enu!ber o clusters isdeter!ined by dividing

total perorated laterallengt/ by *< (/e onlyre!aining unDno"n is' "/ic/ is no" set to

balance t/e e#uation<

A9)o< oclustersL' L2L2L/

+ t l i D l ti Fl


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Assu!ed Maxi!u!3pacing $*%

Assu!ed Mini!u!3pacing $*%

Assu!edMaxi!u!

D

A s s u ! e d

M i n i ! u !

D

H i g / e s t D T

* c o ! b o o

r

" e l l s s t i l l i

n t r a n s i e n

t 5 o "

All possible co!binations o D T * or "ells still intransient 5o"< As t/e "ell continues to produce intransient 5o" t/e line to t/e rig/t "ill !ove steadilyto t/e let until t/e boundary is reac/ed anddepletion 5o" begins<


+ t l i D l ti Fl


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W/en t/e transitionto *inear 4epletion5o" /as beenobserved6 t/epossibleco!binations o Dand * t/at Et t/eobserved data /asbeen Exed andreside on t/e line<

Maxi!u! 3pacing $*% to Etdata

Mini!u! 3pacing $*% to Etdata

Mini!u! Area $A% to Etdata

Maxi!u! Area $A% to Etdata

Assu!

edM

axi!u!

D A s s u ! e d

M i n i ! u ! D


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Summary o% #nalytial #nalysis

1< Assu!ing t/e speciEc geo!etry o a !ulti-ractured /orizontal "ell "it/ a racturedvolu!e extending out ro! t/e lateral<2< Assu!ing all initial 5o" is ro! "it/in t/e 3R+ and is linear and transient< (/e diagnostic superposition ti!e vs< 1:; plot "ill by deEnition be linear "/ere t/e slope

"ill be proportional to AD1:2

7< W/en linear trend o t/e diagnostic plot is establis/ed6 all possible co!binations o Aand D are establis/ed<

@< (/e values o A and D can be li!ited to reasonable !ini!u! and !axi!u! valuesbased on Dno"n rocD properties6 etc<

< (/e size o t/e 3R+ can be li!ited based on reasonable assu!ptions o t/e racturegeo!etry $)o< o ractures6 average proppant density or racture t/icDness6 proppanteJciency% based on experience and reasonable p/ysical li!its<

C< 3ize o t/e 'R+ can be assu!ed based on expected "ell spacing< Wit/ A6 D6 t/e 3R+ and t/e 'R+ deEned as per t/e best !atc/ o observed data6 t/e

diKusivity e#uation can be applied to !odel t/e expected production proEle<I< Once t/e deviation ro! linear transient 5o" is observed6 an additional variable6 t/e

racture spacing6 can be deEned based on t/e !atc/< 4eEning racture spacing alsodeEnes ' and t/e nu!ber o producing ractures and /ence t/e size o t/e 3R+<

1


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Pit%alls o% #nalytial #nalysis

1< Assu!es constant A• natural ractures• *oss o /ydraulic racture A due to conEning stress or isolation• .ossible asperities

2< Assu!es constant Rco!p• Well clean up $sDin6 cap pressure i!bibition6 etc%

• Fcd c/ange

• Wellbore loading< &Kects o staggered racture spacing

• /ange s/ape o diagnostic curve7< Assu!es 1 o early ti!e 5o" is linear transient 5o" "it/in t/e 3R+

• ontribution ro! 'R+ "ill sDe" diagnostic curve@< Assu!es static D

• 4yna!ic Dabs due to conEning stress

• 4yna!ic Drg due to cap pressure eKects

• )on-/o!ogeneous D $vertical and lateral%< )o eKective diagnostic or assu!ed p/ysical constants<

•

3tandard proble! o any !et/od< =nput data suc/ as U6 /6 3"6 etc !ay be inerror<

E l # l ti l # l i


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2

Examle #nalytial #nalysis:ensoter ;-5 2 +nut data

H. 9V uses gradient 9


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Examle #nalytial #nalysis:ensoter ;-5 2 Prodution inut data

u!ulative .roduction 91


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Examle #nalytial #nalysis:ensoter ;-5 2 Ste - 2 Defne a riori limits

Frac t/icDness ro!


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Examle #nalytial #nalysis:ensoter ;-5 2 Ste / 2 Diagnosti Plot

O3&R+A(=O)1Well appearsto be steadilyi!proving or7 to @ !ont/s

O3&R+A(=O)2.ossible lineartransient 5o"ro! 3.( day Cto 3.( day 1

O3&R+A(=O).ossibletransition tolineardepletion 5o"on 3.( day 1

E l # l i l # l i


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2

Examle #nalytial #nalysis:ensoter ;-5 2 Ste < 2 =odel F:5P

,sing !odelpara!eters ro!

t/e diagnostic plot6!odel t/e FH. to

obtain a !atc/ toactual

Rco!p and ; are t"o controlling

variables ro! t/e diagnostic plot<

E l # l ti l # l i


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Examle #nalytial #nalysis:ensoter ;-5 2 Ste > 2 =at7 F:5P

E l # l ti l # l i


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Examle #nalytial #nalysis:ensoter ;-5 2 Ste ? 2 Run imits

O3&R+A(=O) 1

*inear depletion5o" is observedso t/e universeo co!binationso D and * areset

O3&R+A(=O) 2Maxi!u! per!t/at can !atc/est/e universe opossible per!s int/e D:* co!bo is271 nd

O3&R+A(=O) Mini!u! per!t/at can!atc/es t/euniverse opossible per!sin t/e D:* co!bois @C nd

O3&R+A(=O) @

Mini!u! A t/atcan !atc/es t/euniverse opossible per!s int/e D:A co!bo is@


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@

Examle #nalytial #nalysis:ensoter ;-5 2 Ste @ 2 Foreast Prodution

&,R.I 9


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Examle #nalytial #nalysis:ensoter ;-5 2 Ste @ 2 Foreast Prodution

E l # l ti l # l i


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C

Examle #nalytial #nalysis:ensoter ;-5 2 Ste A 2 Sensitivity Foreast

&,R.I 9 @


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Examle #nalytial #nalysis:ensoter ;-5 2 Ste B 2 Comarison to C54 :oo,s

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DD Presentation on Limits