5 pressure basics problems, problems 1-6

7/24/2019 5 Pressure Basics Problems, PROBLEMS 1-6

1/31

PAGE 5

2a. What is the hydrostatic pressure exerted by a

column of 16.8 ppg fluid at 13,780 ft.

!" # $% x .0&2 x '(%

!" # 16.8 x .0&2 x 13780

!" # 12038.208 or

!" # 12038 ")*


2/31

2b. What is the hydrostatic pressure at the casing shoe

in a +ell 10,00 ft. -% 10,000 ft. '(%. 'he mud

+eight is 12.3 ppg and casing is set at &,&/0 ft.-%. &,03 ft. '(%.

!ydrostatic "ressure # $% x .0&2 x '(%

!" # 12.3 x .0&2 x &03

!" # 3222./// or!" # 3223 ")*


3/31

/. +ell drilled to the depth of 11,200 ft. has casing set at 6,220 ft.

'(%. fter drilling out the shoe, the leaoff pressure +as 110

psi using a fluid +eighing .2 ppg. 'he present mud +eight is

10.3 ppg.. What is the estimated integrity fluid density maximum mud

+eight4

5. What is the estimated integrity pressure -)"4a. --W # ' "ress. .0&2 'est %epth4 9 ' -ud Weight

--W # 110 .0&2 62204 9 .2

--W # 3.6718& 9 .2

--W # 12.8718 or 12.8 ppg.

b. -)" # :*$% ; "resent -ud Wt.4 < .0&2 < 'est %epth

-)" # 12.8 ; 10.34 < .0&2 < 6220

-)" # 2.& < .0&2 < 6220

-)" # 808.6 or 808 ")*


4/31

&. !o+ much applied pressure is re=uired to test a formation to the

e=ui>alent of 13.0 ppg 'he +ell is 7,000 ft deep, the casing is set at

3,&00 ft. and the test mud is 8.6 ppg.

pplied "ressure # : - Wt ; "res. - Wt4 x .0&2 x '(%

" # 13.0 ; 8.64 < .0&2 < 3&00" # /./ < .0&2 < 3&00

" # 800.8 ?

" # 801 ")*


5/31

6. What mud +eight is e=ui>alent to a hydrostatic pressure of 11,00 psi

at 13,700 ft

@/

$luid %ensity # !" .0&2 '(%

$% # 1100 .0&2 13700$% # 16.70/08 or

$% # 16.7 ppg.


6/31

"A: 11

1. What is the >olume of 6000 ft. of 13 3B8C casing 'he casing *% is

12.71& in.

(olume # Dapacity x ength

( # *%E 102./4 < 6000

( # 12.71&E 102./4 < 6000( # F12.71& < 12.71&4 102./G < 6000

( # F161.67122 102./G < 6000

( # .1&70&38 < 6000

( # /2.3228 or

( # /2.3 bbls


7/31

/. %ataH 3 IC drillpipe, capacity .007/1 bblBft, displacement .00&1&

bblBft., 7C casing, capacity .0337 bblBft, -ud Weight 11./ ppg.

. !o+ many feet of drillpipe may be pulled JdryC before the !"decreases by 7&psi

-ax. ength "ulled J%ryC # F"ress. %rop .0&2 -ud Wt.4 < Dsg. Dapacity ; "ipe %isplacement4G "ipe %isplacement

-ax. ength "ulled J%ryC # F7& .0&2 11./4 < .0337 .00&1&4G .00&1&

-ax. ength "ulled J%ryC # F126.&1821 < .03/22G .00&1&

-ax. ength "ulled J%ryC # /.32/&31 .00&1&

-ax. ength "ulled J%ryC # 8/0.67 ft. r

-ax. ength "ulled J%ryC # 8/1 ft.


8/31

/. %ataH 3 IC drillpipe,

capacity # .007/1 bblBft displacement .00&1& bblBft.

7C casing # capacity .0337 bblBft

-ud Weight 11./ ppg.

5. !o+ many feet of drillpipe may be pulled J+etC before the

!" decreases by 7&psi

-ax. ength "ulled JWetC # F"ress. %rop .0&2 -ud Wt.4 < Dsg. Dap ; "ipe %ispl. ; "ipe Dap.4G "ipe %ispl. 9 "ipe Dap.4

-ax. ength "ulled JWetC # F7& .0&2 11./4 < .0337 .00&1& .007/14G .00&1& 9 .007/14

-ax. ength "ulled JWetC # F126.&1821 < .02681G .012&6

-ax. ength "ulled JWetC #3.31&32 .012&6

-ax. ength "ulled JWetC # 270.0&6 ft

-ax. ength "ulled JWetC # 270 ft.


9/31

&. %'H

%rillpipe # & in. Dasing # 13 3B8 in.

Dapacity # .01776 bbl B ft Dapacity # .1&/& bbl B ft

%isplacement # .0070 bbl B ft -ud Weight # 1/.2 ppg. !o+ much +ill the !" decrease if +e pull /6& ft. of pipe JdryC"ressure %rop B $t # -ud Aradient x "ipe %isplacement

%ry4 Dasing Dapacity ; "ipe %isplacement

# 1/.2 x .0&24 x .0070

.1&/& .0070# .738/ x .0070

.1/7&

# .00&23&2

.1/7&

# .03&/28 psiBft # .03&/28 x /6&

# 16.&0/1&2 psi or

# 17 psi.

'he boo says 16.3 psi. 'he boo is W?KA.


10/31

&. %'H

%rillpipe # & in. Dasing # 13 3B8 in.

Dapacity # .01776 bbl B ft Dapacity # .1&/& bbl B ft

%isplacement # .0070 bbl B ft -ud Weight # 1/.2 ppg

5. !o+ much +ill the !" decrease if +e pull /6& ft of pipe J+etC

"ressure %rop B $t # -ud Aradient x "ipe %isplacement 9 "ipe Dapacity4

Wet4 nnular Dapacity

# 1/.2 x .0&24 x .0070 9 .017764

.1&/& .0070 .01776

# .738/ x .02/8&

.127/

# .0183/2

.127/

# .1/1/30& psiBft

# .1/1/30& x /6&

# 6&.8 psi or 66 psi.

"A: 7


11/31

"A: 7

@1 'he +ell depth is 11,800 ft. and the mud +eight is 12.2

ppg. Dasing is set at 3770 ft. 'he +ell is shut in on a gas

ic. )*%"" # 220 psi, )*D" # 37& psi. What is the

e=ui>alent mud +eight at the casing shoe

:-W # 'otal pplied "ressure .0&2 '(%4 9 "resent -ud Weight

:-W # 37& .0&2 '(%4 9 "resent -ud Weight

:-W # 37& .0&2 37704 9 "resent -ud Weight

:-W # 37& .0&2 37704 9 12.2

:-W # 1.1287/ 9 12.2

:-W # 1/.11287/ ppg or

:-W # 1/.1 ppg


12/31

PAGE 99

#3 What is the capacity bblsBft4 of 17 IC open hole

*nternal Dapacity # *%E 102./

*nternal Dapacity # 17.&E 102./

*nternal Dapacity # 17.& x 17.& 102./

*nternal Dapacity # 306.2& 102./

*nternal Dapacity # .27&03/ or

*nternal Dapacity # .27&0 bblsBft


13/31

PAGE 100

#11 'he 13 3B8C casing to be run is in Jrandom /0Ls 9 /0 ft

per Moint4. *f the *% is 12.61&C, +hat is the >olume in one

Moint

*nternal Dapacity # *%E 102./

*nternal Dapacity # 12.61&E 102./

*nternal Dapacity # 12.61& x 12.61& 102./

*nternal Dapacity # 1&.13822 102./

(olume # .1&/&31 x /0

(olume # 6.18372/ bbls

(olume # 6.2 bbls


14/31

STOP


15/31

1. Dasing is set at 6000 ft. '(%. n 8 bbl. gain +as

noticed. %epth of the +ell is 12,000 ft. '(% )*%"" is /&0

psi and )*D" is 800 psi. 'he mud +eight is .8 ppg. Whatis the estimated formation pressure

$ormation "ressure # !"dp9 )*%""$" # $% < .0&2 < '(%4 9 /&0

$" # .8 < .0&2 < 60004 9 /&0

$" # 30&7.6 9 /&0

$" # 3&07.6

$" # 3&08 ")*


16/31

2. !o+ much +ould the !" be reduced if 0 ft. of 6 IC drill

collars +ith an *% of 1 NC +ere pulled dryfrom 8 1B8C casing

+ithout filling the annulus. Dasing capacity is .0&1&6 bblBft.

Dollar capacity is .0030 bblBft and displacement is .0381

bblBft. -ud +eight is 13.& ppg.

psiBft # -ud Aradient < "ipe %isplacement

Dasing Dapacity ; "ipe %isplacement

psiBft # 13.& < .0&24 < .0381

0.0&1&6 0.0381

psiBft # 0 .702 < .0381

0.013/6

psiBft # 0.0267/62

0.013/6

psiBft # 1.870876

psiBft # 1.870876 < 0

psiBft # 178.83788

psiBft # 17 psi


17/31

3. !o+ many barrels of fluid +ould it tae to fill

/3& ft. of /C drill pipe +ith an *% of 3.3/0C

*nternal Dap. # *%E 102./4 < ength

*nternal Dap. # 3.3/0E 102./4 < /3&

*nternal Dap. # 11.1&&6 102./4 < /3&

*nternal Dap. # .010836 < /3&

*nternal Dap. # /.71/0&1&

*nternal Dap. # /.7 55


18/31

/. Dasing +as set at &&3/ ft. '(%. fter drilling 2& ft of

ne+ hole +ith 11.2 ppg mud, the +ell +as circulated

clean. 'he drilling program called for the formation atthe casing shoe to be tested to an e=ui>alent mud +eight

of 1/.& ppg. What surface pressure +ill be re=uired

" # :-W ; D-W4 < .0&2 < '(%

" # 1/.& ; 11.24 < .0&2 < &&3/

" # 3.3 < .0&2 < &&3/ " # /.63//

" # &0 psi


19/31

&. 5efore a trip out of the hole, the pits held 62& barrels of

12.6 ppg mud. What should the pit >olume be after

tripping out JdryC

%ataH

7&0 feet of 7C drill collars 12,300 feet of & IC drillpipe

Dapacity # .0073 bblBft Dapacity # .02162 bblBft%isplacement # .0/03bbBft %isplacement # .002& bblBft

8 &B8C pen hole ne stand of drillpipe is 3ft. long.


20/31

&.

'otal %" # %isplacement < ength'otal %" # .002& < 12300

'otal %" # 113.77&

'otal %" # 11/ bbl

'otal Dollar %ispl. # %isplacement < ength

'otal Dollar %ispl. # .0/03 < 7&0

'otal Dollar %ispl. # 30.22&

'otal Dollar %ispl. # 30 bbl"it (ol. # riginal (ol. ; %" %ispl. ; Dollar %ispl.

"it (ol. # 62& ; 11/ 30

"it (ol. # /81 bbl


21/31

O6. %rilling fluid used in a +ell has a density of 16.8 ppg.

!o+ many JdryC stands 3feet per stand4 may be pulled

before the !" is reduced by 7& psi Dasing capacity is .060&

bblBft and drillpipe displacement is .00818 bbl.

-"% # F"ress. %rop .0&2 -W4 < D)A Dap ; "ipe %ispl. 4G "ipe %ispl.

-"% # F7& .0&2 16.84 < .060& .008184G .00818

-"% # F8&.8&16/2 < .0&277G .00818

-"% # /.&3031 .00818

-"% # &&3.837&/

-"% # &&/ ft.


22/31

O7. With casing set at /000 ft '(%, a leaoff test

+as conducted. 'he '" is &0 psi using .7ppg fluid. %rilling resumed and at 10&00 ft, the

+ell iced +ith 10.& ppg mud in the hole. 'he

+ell +as shut in and pressures stabiliPed +ith a)*%"" of 2&0 psi and )*D" of /7&. !o+ much

pressure the formation liely +ithstand before

breaing do+n


23/31

7. --W # '" .0&2 '(%4 9 'est - Wt.

--W # &0 .0&2 /0004 9 .7

--W # /.&67307& 9 .7--W # 1/.2 ppg

-)" # :*$% ; "res. - Wt.4 < .0&2 < '(%

-)" # 1/.2 ; 10.&4 < .0&2 < /000

-)" # 3.7 < .0&2 < /000

-)" # 76.6

-)" # 76 psi

dded "ress. # -)" )*D"dded "ress. # 76 /7&

dded "ress. # 2/ ")*


24/31

O8. When drilling ahead +ith a 10.& ppg mud, a 1& barrel

ic +as taen and the +ell +as shut in. )hutin pressures

stabiliPed at )*%"" of 301 psi and )*D" of &2& psi. 'heformation fracture at shoe depth of 3&00 ft '(% +as estimated

to be e=ui>alent of a fluid density of 1&.0 ppg. What is the

e=ui>alent mud +eight at the casing shoe no+

:-W # )*D" .0&2 '(%4 9 "res. - Wt.

Q :-W # &2& .0&2 3&004 9 10.&

Q :-W # 2.88/61&1 9 10.&

Q :-W # 13.38/61&

Q :-W # 13./ ppg


25/31

O. *f 5!" exceeded formation pressure by 200 psi

using 11.7 ppg mud, ho+ far +ould the fluid ha>e to fall

before losing the o>erbalance

'(% # !" $% .0&2

'(% # 200 11.7 .0&2

'(% # 328.7310

'(% # 32 ft.


26/31

10. ssume a JdryC trip out of the hole using &C drillpipe

capacity # .0171 bbls. ft and .00827 bblsBft displacement4.

'he casing *% is 8.83&C and the mud +eight is 16.7 ppg. !o+

much !" is lost if 260 feet of pipe is pulled +ithout filling thehole

")*B$' # $A x "ipe %isplacement

Dsg. Dap. ; "ipe %ispl.

")*B$' # 16.7 x .0&24 x .008274

*%E 102./4 .00827")*B$' # 16.7 x .0&24 x .008274

8.83&E 102./4 ; .00827

")*B$' # .868/ x .00827

.07&8278 .00827")*B$' # .0071816

.067&&78

")*B$' # .16303 ")*B$' x 260

")*B$' # 27.63878 ")*

")*B$' # 28 ")*


27/31

What is the !" at the casing seat in a +ell 128/0 ft. -%

6& ft. '(% 'he casing is set at &280 ft. -% and 372

ft. '(%. 'he mud +eight is 11.& ppg.

!" # $% x .0&2 x '(%

!" # 11.& x .0&2 x 6&

!" # &776.082 psi

!" # &776 psi


28/31

Q-1 (S)The well took partial losses as it is drilled to

9600 ft TVD. Driller quickl li!ed up a!d "lledthe hole with sea water de!sit of #.$ pp%u!til the &uid le'el stailied at surface. The*+ at the ti,e of losses was 1.$ pp%. Thefor,atio! stre!%th at the loss o!e isesti,ated to e 0.$1$ psift.

/alculate the hei%ht of sea water colu,!whe! the well stailied.


29/31

O2'he 12 R Jhole +as drilled to 600C -% and .&B8 casing +as

run and cemented at &&60 ft '(% +ithout any problem. fter

drilling out the shoetrac and 1& ft of ne+ formation a leaoff

test +as performed. 'he leaoff pressure is estimated to be 380psi +ith 12.8 ppg mud in hole. %rilling continued and the +ell

too a gas ic at 880 ft '(% +ith 13.& ppg drilling mud. 'he

+ell +as shut in successfully and pressures +ere allo+ed to

stabiliPedH ?eadings are as follo+sH)*D" # 180 psi )*%"" # 110 psi "it Aain # / bbls

What is the safety margin

a. 18 psi

b. /7 psi

c. &6 psi

d. Ko -argin


30/31

$racture "ressure # 380 9 12.8 x 0.0&2 x &&60

$racture "ressure # 380 9 3700.736

$racture "ressure # /081 psi

)o the maximum limit is /081 psi SS

pplied pressure no+ # 180 9 13.& T 0.0&2 T &&604pplied pressure no+ # 180 9 303.12

pplied pressure no+ # /083 psi

)o the current applied pressure at the shoe is more than

the fracture pressure.

Ko safety margin left.


31/31

THE

END

5 pressure basics problems, problems 1-6

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