Reservoir Engineering Lab
EXPERIMENT 1
POROSITY MEASUREMENT OBJECTIVE
To determine the porosity of reservoir rock samples. sa mples.
APPARATUS
Helium Porosimeter Mercury Porosimeter Vanier Caliper
BASIC THEORY a)
Porosity
Porosity is a measure of storage capacity of a reservoir. It is defined as the ratio of the pore volume to bulk volume. In general, a core sample can have three types of volumes, namely the pore volume, the grain volume, and the bulk volume. Thus, porosity can determine from these euations!
Porosity
Vp Vb
Vb
Vgr Vb
Vp Vp
%#%
Vgr
"#$
Reservoir Engineering Lab
&here, V p ' pore volume Vgr ' ' grain volume V b ' bulk volume Porosity is may be e(pressed as either a percent or a fraction. T&o types of porosity may be measured! total or absolute porosity and effective porosity. porosity. )bsolute porosity is the ratio of all the pore spaces in the rock to the bulk volume of the rock. *ffective porosity is the ration of interconnected void spaces to the bulk volume. Thus only the effective porosity contains fluids that can be produced from the &ells. +or granular materials such as sandstone, the effective porosity may approach the total porosity, ho&ever, for shales and for highly cemented or vugular rocks rocks such such as some some limesto limestones nes,, large large variat variation ionss may e(ist e(ist bet&ee bet&een n effect effective ive and absolute porosity. porosity. )bsolute porosity '
*ffective porosity '
1)
Tota Tota por! por! "o#$! "o#$! B#% "o#$! "o#$!
I&t!r'o I&t!r'o&&!' &&!'t!(por! t!(por! "o#$! B#% "o#$! "o#$!
"$
"-$
B#% Vo#$! M!as#r!$!&t
There are several methods may be used to measure bulk density! "a$ "a$ ete eterm rmin inati ation on &it &ith h cali calipe perr to meas measur uree the the diam diamete eterr and and len lengt gth h of of core core sample, and calculate the bulk volume. "b$ "b$ ete eterm rmin inat atio ion n &ith &ith merc mercur ury y disp displa lace ceme ment nt.. "c$ "c$ ete eterm rmin inati ation on &it &ith h core core sam sampl plee imme immersi rsion on,, and and calc calcul ulat atee the the vol volum umee using )rchimedes principle. "d$ "d$ ete eterm rmin inati ation on &ith &ith tota totall gra grain in volu volume me and and por poree vol volum ume. e.
)
Por! Vo#$! M!as#r!$!&t
There are several methods may be used to measure bulk density! "a$ "a$ ire irect ct mea measu sure reme ment nt usin using g por poros osim imet eter er app appar arat atus us.. "b$ "b$ /rav /ravity ity meth method od 0 core core is is satu satura rate ted d &ith &ith li liui uid d &ith &ith kno kno&n &n den densi sity ty.. "c$ "c$ 1y subt subtra ract ctin ing g gra grain in volu volume me from from bulk bulk volu volume me..
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Reservoir Engineering Lab
*)
+rai& Vo Vo#$! M! M!as#r!$!&t
There are several methods may be used to measure bulk density! "a$ "a$ ire irect ct mea measu sure reme ment nt usin using g por poros osim imet eter er app appar arat atus us.. "b$ 1y us using )r )rchimede edes pri principle. "c$ "c$ 1y subt subtra ract ctin ing g por poree vol volum umee fro from m bul bulk k vol volum ume. e.
b)
+rai& ,!&sity
2ometime density of the grain is reuired in the porosity calculation, for e(ample, in the determination of grain volume if the &eight of grain is kno&n. +urther more, grain density may be also needed in the porosity calculation by density log. In euation form -gr gr
"3$
Vgr
&here, ρgr ' ' grain density 4gr ' ' grain &eight Vgr ' ' grain volume
BASIC THEORY O. THE E/UIPMENT
Helium porosimeter is an euipment to measure volume. It may be used to measure the grain volume "Vgr $or $or the pore volume "V b$ of a rock sample. It is applying the 1oyle 5a& of gas e(pansion principle. 2ome uantity uantity of helium helium gas &ith kno&n volume volume "reference cell volume$ as measured measured at an initial pressure is let to e(pand isothermally to fill the cell of the unkno&n volume. )fter e(pansion, the resulted pressure is recorded. Ho& big the value of this unkno&n cell volume is further calcuted using 1oyle 5a&.
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Reservoir Engineering Lab
The processes are illustrated in the follo&ing figure.
6eferring to above figure, some standard pressure "usually #77 psig$ is applied bet&een source valve and core holder valve. 4hen the core holder valve is opened, #77 psig pressure &ill e(pand and fill the unkno&n volume "initial at 7 psig$. 4hen both pressures have reached euilibrium, 1oyle 5a& may be used to calculate the total unkno&n volume. The processes are summari8ed as follo&! +rom 1oyle 5a&, P1VR
P) V
T1
T)
P* VR
V
T*
&here, P# ' pressure of reference cell "core holder valve is closed$, psia P ' pressure in the unkno&n volume, psia P- ' pressure at euilibrium "core holder valve is opened$, psia V6 ' ' volume of reference cell, cmV ' the unkno&n volume, cm T#, T, T- ' absolute temperatures, o6 or o: ;ormally, ;ormally, P# ' #77 psig, and P ' 7 psig. *n. 9 becomes,
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Reservoir Engineering Lab
P1
B VR
P1 VR
BVR
BV
P1 P*
B
BV P* VR
P* V VR P1 V VR
P*
VR BVR
V P*V
BV
P* 1
VR
100 P*
1
"<$
&here, 1 ' barometer pressure, psi P#, P- ' pressure in psig Ho&ever, the values of V 6 and and V are constant. Volume V 6 &hich &hich is consist of Heise gauge &ith bourdon tube &ill e(pand and shrink according to pressure changes. This is due to small changes of volume in pipe and valve during pressure euilibrium process. It may be proofed that! V VR
P1 P*
1
P*
B
P*
+
100 P*
"=$
&here, / ' system e(pansion factor, cm->psi
EXPERINMENTA PROCE,URES
#.
4eigh ight the the core core sam sample, ple, and and measu easure re the the core core leng length th and and diam diamet eter er usin using g Vanier nier caliper.
.
Conn Connec ectt the the heli helium um gas gas sour source ce at at the the pan panel el &it &ith h all all val valve vess are are clos closed ed e(ce e(cept pt the the core core holder valve and e(haust valve are opened. )d?ust the pointer to 7 psi.
-.
Clos Closee the the core core hold holder er val valve ve,, and and then then ope open n the the supp supply ly val valve ve and and the the sou sourc rcee valv valve. e. )d?ust the pointer of cylinder measuring gauge to #77 psi &ith the regulator. 2lo&ly tap the porosimeter so the dial reading is at #77 psi.
3.
6epe 6epeat at ste steps ps and and - abo above ve severa severall tim times es unt until il the the stabl stablee read readin ing g is is achi achiev eved ed..
9.
Inse Insert rt cor coree samp sample le int into o the the matr matri( i( cup cup,, foll follo& o&ed ed by the the disk disk unt until il bot both h are are at at the the same same level or slightly lo&er than the height of the cup, and tighten the lid up to ma(imum.
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Reservoir Engineering Lab
;ote! +or #.9 inch diameter core the height of the disk must be slightly lo&er than the height of the cup to avoid it from touching the internal @ ring "actually the @ ring is for # inch core$. @ther&ise, remove the internal @ ring. <.
The volu volum mes are are deter eterm mined ined by th the fol follo lo&i &ing ng step steps! s! a$ b$ c$ d$ e$ f$
g$ h$
Clos Closee the the Cell Cell # Valve, lve, the the Cel Celll Valve lve and and the the Core Core Hold Holder er Valve. lve. @pen the 2upply Valv Valvee and the 2ource Valv Valve. e. )d?u )d?ust st reg regul ulat ator or unt until il the the dial dial rea readi ding ng sho& sho&ss e(ac e(actl tly y at at #77 #77 psi psi.. Close Close the the 2ource 2ource Valve, lve, follo follo&ed &ed by the 2upply 2upply Valve and the *(haus *(haustt Va Valve. lve. @pen @pen the the Cor Coree Hold Holder er Valve, lve, and and obser observe ve the the movem movement ent of the the dial dial in opp oppos osit itee direction from the clock&ise. 4hen 4hen the the dia diall stop stops, s, tap tap the the por poros osim imet eter er and and rec recor ord d the the read readin ing g of the the out outsi side de scale. This is a Avolume &ith sampleB "i.e. sample volume disk volume$. 6ecord the gauge reading. Clos Closee the the Core Core Hold Holder er Valve lve so so gas gas is rele releas ased ed out. out. @pen @pen *(ha *(haus ustt Va Valve lve so so the the press pressur uree in in the the matri matri( ( cup cup beco become mess 7 psi. psi.
=.
5oos 5oosen en up up the the lid and and rem remov oved ed mat matri ri( ( cup fro from m its its hold holder er.. 6emo 6emove ve the the core core sam sample ple but left the disk inside and retighten the lid.
D.
6epe 6epeat at step stepss <"a%h <"a%h$. $. 6eco 6ecord rd the the readi reading ng of of Avolu Avolume me &ith &ithou outt sampl sampleB eB "dis "disk k volu volume me only$.
E.
+or +or bigg bigger er Aun Aunkno& kno&n n volu volum meB such such as bet bet&e &een en 97 97 cc to 397 397 cc, cc, open open cel celll # and and repeat steps < to D.
#7. #7.
+or +or much much bigg bigger er Aunk Aunkno no&n &n vol volum umeB eB such such as bet bet&e &een en #97 #97 cc to DD7 DD7 cc, cc, ope open n cell cell # and cell , and repeat steps < to D.
##.
5oos 5oosen en up the the mat matri ri( ( cup cup lid lid and and remo remove ve it. it.
#.
@pen co core sam sample ho holder va valve.
#-. #-.
4hen 4hen fini finish sh,, clo close se the the gas gas cyli cylind nder er valv valve. e.
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Reservoir Engineering Lab
,ata
6oom Temperature
'
FFFFFFFFFFFFFFFFFFFF
1arometric Pre Pressure '
FFFFFFFFFFFFFFFFFFFF
12
Basi' ,ata
Na$! o3 Sa$p!
2
Na$! o3 Sa$p!
-!ig4t 5g$)
!>4 5'$)
,ia$!t!r 5'$)
Vo#$! 6it4 Sa$p! 5'')
Vo#$! 6it4o#t Sa$p! 5'')
B#% B# % Vo#$! #$!77 +ra +rai& i& Vo#$!7 #$!7 Por! Por! Vo#$! #$! a&( a&( Por Poros osit ity y ,at ,ata a
B#% Vo#$! 5Vb) 5'')
+rai& Vo#$! 5Vgr) 5'')
%=%
Por! Vo#$! Vo#$! 5Vp) 5'')
Porosity 5 ) 58)
Reservoir Engineering Lab
INSTRUCTIONS AN, /UESTIONS
#.
ete eterm rmin inee the val value uess of poro porosi sity ty and and den densi sity ty for for the the all roc rock k sampl samples es.. 4hat 4hat type type of porosity that you are measuredG
.
Make comparison of the bulk volume of the rocks measured from mercury displacement method and ordinary measurement method.
-.
/ive /ive three three reaso reasons ns &hy &hy heli helium um gas gas is is use used d not not othe otherr gase gasess for for this this e(p e(per erim imen ent. t.
3.
Is it pos possi sibl blee for the the hel heliu ium m poro porosi sime mete terr to be used used for for oth other er than than cyli cylind ndri rica call core core samples, such as suare or irregular shape core samplesG a$ b$
If not, e(plain your re reasons. If yes, &hich shape gives the most accurate porosity result
9.
) cor coree sampl samplee &as tak taken en from from a &ell &ell and and por poros osit ity y meas measur urem emen entt &as con condu duct cted ed.. Is true that the porosity porosity measured in the laboratory is the same &ith the porosity of the sample at the reservoir conditionsG
<.
4hat 4hat are are the the adv advan antag tages es of of the the poro porosi sity ty meas measur urem emen entt in the the labo labora rato tory ry as as comp compar ared ed to from the logging toolsG =. The poros porosity ity of the rock sample sample can also be determi determined ned by measure measuremen mentt of grain grain volume method. This method reuires the &eight and the density of the grain. *(plain the calculation procedures, and give advantages and disadvantages of this method.
EXPERIMENT %D%
Reservoir Engineering Lab
MEASUREMENT O. I/UI, PERMEABIITY ,ETERMININ+ THE PERMEABIITY O. A ROC9 SAMPE USIN+ I/UI,
Ob:!'ti"!
Measuring absolute permeability of a rock sample using liuid as a fluid Apparat#s
#.
5iuid Permeameter
.
Vernier Caliper
Basi' T4!ory;
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Reservoir Engineering Lab
12
Ro'% P!r$!abiity
Permeability is a measure of the ability of a porous media to permit fluid to pass through it. +or rocks, it describes the relative ease of the fluid to move through the net&ork of pores inside the rock. If only one fluid is present inside the rock, the measured permeability is referred to as A)bsolute PermeabilityB. If more than one fluid is present, the measured permeability &ill be lo&er and the value is no& referred to as A*ffective PermeabilityB. 2
,ar'y E<#atio&
The euation used to measure rock permeability is called arcy *uation. +or a linear system &ith liuid as the fluid, arcy euation can be &ritten as! Q=
kA ( P# − P ) uL
4here, k ' permeability "darcies$ ) ' cross sectional area of the sample "cm $ P# 0 P ' pressure difference "atmosphere$ u ' viscosity "cp$ 5 ' length of the core "cm$ ' flo& rate "cc per sec$
*2
M!as# !as#rr!$!& $!&t o3 o3 Ro' Ro'% % P!r P!r$! $!a abii biitty #si #si& &g i< i<# #i(
)bsolute permeability is a rock property. The The value can be obtained using arcy euation. +luid of certain viscosity is flo&ed through the rock sample at certain pressure. The resulting flo& rate is measured. 1ased on the data, the permeability of the rock sample can be calculated. The permeability measured using liuid flo&ed through the rock is the rock permeability, so long as there is no reaction bet&een the rock and the liuid.
M!as#r!$!&t o3 P!r$!abiity
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Reservoir Engineering Lab
M!t4o(
#.
Measure the sample dimensions radius and length
.
Make sure the system is connected to the gas source through a closed AFvalveB
-.
Inser Insertt the the samp sample le &hi &hich ch had had bee been n satu saturat rated ed &it &ith h the the li liui uid d into into the the rub rubbe berr stop stoppe per r
3.
Inser Insertt the the rubb rubber er stopp stopper er cont contain ainin ing g the the sam sampl plee int into o the the core core hold holder er
9.
Tighten the core holder underneath the apparatus and connect to the top part. Tighten Tighten using the handle, nether too tight, nor too loose.
=.
@pen @pen by turn turnin ing g the the disc discha harg rgee fill fill val valve ve to to fill fill the the bur buret ette te and and the the core core hol holde der r
D.
4hen the liuid level inside the burette has reached the uppermost mark "&ith a slight e(tra of # cm$, close the core holder valve
#7.
2lo&ly open the gas regulator valve and increase the pressure to #.9 atm
##. ##.
Turn Turn the the disch discharg argee fill fill valv valvee to drain drain the the liu liuid id from from the burett burettee into into the the sample sample
#.
Jse the stop &atch to measure time needed for the liuid to flo& from the top level to the bottom level. ;ote the flo& rate.
#-.
Calculate the permeability of the sample
#9.
6epeat steps #7%#- by increasing the inlet pressure to atm
#<
. 6ep 6epea eatt the the perm permeab eabil ility ity measu measurem remen entt "ste "step p #3$ #3$ by measu measuri ring ng the the samp sample le permeability from the opposite direction
R!s#ts o3 t4! E=p!ri$!&t
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Reservoir Engineering Lab
5 ' %%%%%%%%%%%%%%%%%%%%%%%%%% cm u ' %%%%%%%%%%%%%%%%%%%%%%%%% cp ' %%%%%%%%%%%%%%%%%%%%%%%% cm
T!st 1
T!st
T!st * 5 Opposi&g (ir!'tio&)
P# ' %%%%%%%%%%%%%% atm V ' %%%%%%%%%%%%%% cc T# T TTavg sec sec sec sec
P# ' %%%%%%%%%%%%%% atm V ' %%%%%%%%%%%%%% cc T# T TTavg sec sec sec sec
P# ' %%%%%%%%%%%%%% atm V ' %%%%%%%%%%%%%% cc T# T T- Tavg sec sec sec sec
' %%%%%%%%%%%%%% "cc>sec$
' %%%%%%%%%%%%%% "cc>sec$
' %%%%%%%%%%%%%% "cc>sec$
: ' %%%%%%%%%%%%%% m
: ' %%%%%%%%%%%%%% m
: ' %%%%%%%%%%%%%% m
/#!stio&s;
#.
1ased on the e(periment, is there any difference in the value of permeability among the tests. *(plain
.
*(plain the sources of error that might be committed during the measurements of permeability using liuid
3.
4hat is the dimension for permeability, kG 2ho& e(plicitly ho& you can obtain it. 4hat other units can be used for permeabilityG
9.
If the permeability of a sandstone core is measured using salt &ater, and the permeability is measured -77 md, &hat &ill be the permeability of the same core if fresh &ater is used insteadG 4hy is that soG
<.
iscuss briefly &hat is meant by an anisotropic property of the rock permeability
EXPERIMENT *
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Reservoir Engineering Lab
MEASUREMENT O. 9INEMATIC VISCOSITY
OBJECTIVES !
i.
To dete determ rmin inee the the visc viscos osity ity cons consta tant ntss for for glass glass capi capilla llary ry at at diff differe erent nt tem tempe perat ratur ures. es.
ii. ii.
To dete determ rmin inee the the kin kinem emati aticc visco viscosi sity ty of of liu liuid idss by usin using g glass glass capi capill llary ary at different temperatures.
iii. iii.
To dete determ rmin inee the the effe effect ct of of temp tempera eratu ture re on on kin kinem emati aticc visco viscosi sity ty..
iv. iv.
To dete determ rmin inee the the dyna dynami micc fluid fluid vis visco cosi sity ty at at diff differ eren entt temp tempera eratu tures res..
THEORY ! ,YNAMIC VISCOSITY
)s a fluid moves, a shear stress is developed in it, the magnitude of &hich depends on the viscosity of the fluid. 2heer stress "τ "τ$ can be defined as the force reuired to slide one unit area of a substance over another. Thus, τ is a force divided by an area and can be measured in the unit of ;>m " or Pa$. In a fluid such as &ater, oil, alcohol or other common liuids the magnitude of the shearing stress is directly proportional to the change of velocity bet&een different positions in the fluid.
τ ' µ " ∆ν > ∆ν > ∆y$
KKKKKK "*uation #$
&here ! τ ' sheer stress ∆ν ' ∆ν ' change in velocity of fluid particle ∆y ' distance traveled by the fluid particle µ ' constant of proportionality, called dynamic viscosity. viscosity.
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Reservoir Engineering Lab
+or the purpose of clarity, c larity, let gives the symbol µd for dynamic viscosity. U&it Syst!$ 2I 2ystem J2 2ystem cgs system
,y&a$i' "is'osity 5 ( ) U&its ;.s>m, Pa.s or kg>m.s lb.s>ft or slug "ft.s$ Poise ' dyne.s>cm'g>"cm.s$'7.# Pa.s Centipoises ' poise>#77 ' 7.77# Pa.s ' #.7 mPa.s
9INEMATIC VISCOSITY
Many calculations in fluid mechanics involve the ratio of the dynamic viscosity to the density of fluid. ' µd > ρ µk '
KKKKKK"*uation $
&here ! µk ' ' kinematic viscosity µd ' dynamic viscosity ρ ' density of fluid
U&it Syst!$ 2I system J2 system cgs system
9i&!$ati% Vis'osity7 5 % ) ) U&its m>s ft>s Centistokes ' stoke>#77 ' #(#7%< m>s ' # mm >s
The dimension for kinematik viscosity is 5 >T.
MEASUREMENT O. VISCOSITIES
The direct measurement of viscosity is based on the correlation, µ ' 6 3tP>DV5
KKKKKK"*uation -$
&here! V ' volume of liuid, cc t ' flo&ing time, second r ' radius of capillary tube, cm 5 ' length of pipe, cm P ' Pressure ;>cm µ ' absolute viscosity, poise
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Reservoir Engineering Lab
The direct measurement of absolute viscosity is difficult. +or simplicity, the measurement of viscosity normally used the same euipment and t&o types of liuid. Jsing the follo&ing relationship!
µ#> µ ' "ρ# t#$ > "ρ "ρ t$
KKKKKK. "*uation 3$
&here ρ ' density of liuid, gm>cc t ' time taken to flo& in the capillary, second #, ' type of liuid used
1asically the method used to measure the viscosity is by measuring the time time taken for the liuid to flo& in the capillary at a given temperature.
µk ' c t
KKKKKK"*uation 9$
4here c ' viscometer constant, cts>s t ' time of flo&, s ' kinematic viscosity µk '
APPARATUS !
a. b. c. d. e. f. g.
Capi Capill llary ary glass glass visco viscome meter ter 1ath Ther Therm momet ometer er bat bath h 2top&atch Picknometer 1alance Vacuum cuum pump ump
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Reservoir Engineering Lab
PROCE,URES!
a. Jse &at &ater er as as the the stand standard ard liu liuid id.. b. Jse pipette to pour #7 ml of &ater into the capillary glass viscometer. Put the capillary glass viscometer into the bath. 4ait until the temperature of &ater and instrument is eual. c. Jsing a vacuum vacuum pump, pump, suck &ater in the capillary capillary glass glass viscomete viscometerr until the the &ater &ater level is about 9 mm above the level in the viscometer. d. Measure the the time taken taken for the the &ater to flo& flo& from the the high high level to the lo& level level of the viscometer. If the flo&ing time is less than 77 seconds , repeat the test by using a smaller capillary. e. 6epeat 6epeat the above above e(per e(perime iment nt at differen differentt temperat temperature ures. s. f. 4hen 4hen the the kinem kinemat atic ic visc viscos osity ity,, µk of &ater is kno&n, the viscometer constant can then be calculated.
,!t!r$i&atio& o3 i<#i( ,!&sity;
a. 4eigh eigh the empty empty pycno pycnomet meter. er. b. +ill in the pycnometer &ith the liuid and &eigh it. c. The differen difference ce in &eight &eight is the &eight &eight of the liuid liuid in the pycnomet pycnometer. er. d. 1y kno&ing kno&ing the the volume volume and density density,, the viscomet viscometer er constant constant at each test test temperature can be determined.
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Reservoir Engineering Lab
,!t!r$i&atio& o3 9i&!$ati' Vis'osity o3 i<#i(;
The method similar as above, but no& another liuid is used instead of &ater.
Tab! 1 ; ,!t!r$i&atio& o3 i<#i( ,!&sity
T!$p!rat#r! o3 i<#i(7 T oC
-!ig4t o3 !$pty Py'&o$!t!r7 5g$)
-!ig4t o3 py'&o$!t!r 3i 6it4 t4! i<#i(7 5g$)
Vo#$! o3 t4! i<#i( 5 '')
,!&sity o3 t4! i<#i( 5g$>'')
Tab! ; ,!t!r$i&atio& o3 9i&!$ati' Vis'osity
T!$p!rat#r!s o3 T!$p!rat#r!s i<#i(7 T oC
Co&sta&t No2 o3 gass 'apiary
Ti$! ta%!& to 3o6 3ro$ top to botto$ o3 gass 'apiary7 t 5s)
9i&!$ati' "is'osity7 % i& 'ts>s
/UESTIONS!
#. 4r 4rite ite do&n do&n the the Poiseu Poiseuill illee *uati *uation. on. . oes the the above above euation euation applies applies to turbul turbulent ent flo&G flo&G *(plain *(plain.. -. +rom *uati *uation on - , determine determine the the dimension dimension of unit unit poise in in cgs system. system. 3. 4hy does does in these these e(perim e(periments ents , the the velocity velocity of liuid liuid must not be be too highG 9. 4hat is the the effect of of temperature temperature on kinem kinematic atic viscosity viscosity.. Plot Plot kinematic kinematic viscosities against temperatures. *(plain your results.
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Reservoir Engineering Lab
EXPERIMENT ? PERMEABIITY MEASUREMENY BY +AS PERMEAMETER Ob:!'ti"!;
Measuring the absolute permeability of a rock sample using gas and understanding the :linkenberg *ffect. Apparat#s;
/as Permeameter Vernier Caliper
Basi' T4!ory; 12 Ro'% Ro'% P!r P!r$! $!ab abi iit ity y
Permeability is a measure of the ability of a porous media to permit fluid to pass through it. +or rocks, it describes the relative ease of the fluid to move through the net&ork of pores inside the rock. If only one fluid is present inside the rock, the measured permeability is referred to as A)bsolute PermeabilityB. If more than one fluid is present, the measured permeability &ill be lo&er and the value is no& referred to as A*ffective PermeabilityB.
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Reservoir Engineering Lab
2 ,ar' ,ar'y y E< E<#a #ati tio& o&
The euation used to measure rock permeability is called arcy *uation. +or a linear system &ith liuid as the fluid, arcy euation can be &ritten as! Q
=
kA ( P#
−
P, )
uL
4here, k ' permeability "darcies$ ) ' cross sectional area of the sample "cm$ P# 0 P ' pressure difference "atmosphere$ u ' viscosity "cp$ 5 ' length of the core "cm$ ' flo& rate "cc per sec$
If gas &as used as the fluid, the euation used to calculate flo& in porous media is as follo&s! Q
=
kA ( P#
−
P, )
uL
or
&here m
'
cc per sec at pressure
a L 5 ) P
' ' ' ' '
cc per sec at # atmosphere cp cm cm atm
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Reservoir Engineering Lab
*2 M!as# M!as#ri& ri&g g ro'% ro'% p!r$!a p!r$!abi biity ity #si&g #si&g gas gas
Permeability is a rock property. Its Its value can be determined using arcy euation by flo&ing fluid through the rock at a specific pressure. The measured permeability is eual to the permeability measured using liuid. Ho&ever, if gas &as used, the measured permeability value varied depend on the type of the gas and the pressure used. )s a result, if gas &as used as the fluid, the measured permeability value need to be corrected. The correction method is kno&n as :linkenberg Correction. ;ormally the permeability value measured using gas is greater than the value measured using liuid. This This is because, if liuid &as used, the liuid velocity at the pore &all is 8ero. @n the other hand, hand, if gas &as used, the velocity of gas at the &all is not 8ero. This phenomena is kno&n as gas slippage. The amount of slippage depends on flo&ing average gas pressure and the rock characteristics. Mathematically the relationship bet&een actual permeability and the measured permeability can be sho&n as
4here '
permeability measured using arcy euation &ith gas as the flo&ing fluid
'
actual pe permeability, &hen me measured us using li liuid
'
cons consta tant nt,, var varie iess acc accor ord ding ing act actua uall per perm meabi eabili lity ty,, ro rock char charac acte teri rist stic icss and and type of gas '
average permeability
+ig sho&s e(ample of various relationship different gases and average pressures for a rock sample. ) lighter gas &ill have bigger slope, &hich mean greater great er slippage effect. )ll the lines e(trapolated to #>Pm eual to 8ero &ill meet at one point. The value of permeability at this point is the real absolute permeability,
, ie the permeability value measured using liuid.
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Reservoir Engineering Lab
+ig . Variation Variation in gas permeability &ith mean pressure press ure and type of gas
Pro'!(#r!
#. Measure the length length and the diameter diameter of the the core and calcula calculate te the cross%section cross%sectional al area. Jse cgs unit. . Put the the core into into the rubber rubber stopper stopper and then into into the core core holder holder and tighten tighten it. -. )d?ust )d?ust the variable variable valve to AlargeB AlargeB position position.. Turn Turn on pressure pressure regulator regulator slo&ly slo&ly until 7.# atm. 3. 6ecord the the gas flo& rate using using A4et A4et Test Test +lo& +lo& meterB meterB by recording recording the volumes volumes at various times
9. 6epeat the the procedure procedure for pressure pressure different different of 7., 7., 7.3, 7.< 7.< and 7.D atm, atm, and record record the volumes and times. ;ote! a. @utl @utlet et press ressu ure P is # atmosphere "# atm$. b. Pressure gauge reading is the pressure different "NP$ c. Inle Inlett pre press ssur uree P# ' /auge reading # atm d. )verag eragee pres pressu sure re Pm ' "Pinlet Poutlet $> '
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Reservoir Engineering Lab
/#!stio& #.
Calculate mean pressures and its reciprocal "#>Pm$.
.
Calculate gas permeability using appropriate euation.
-.
Plot kgas versus #>P m
3.
etermine liuid permeability "k l$ ' absolute permeability sample.
9.
<.
=.
4hat is the dimension for permeability "k$G 2ho& clearly the derivation of the dimension. Measurement of permeability by using gas &ill usually gives permeability value that is different compared to the one by using liuid. escribe the reason for this phenomena. Permeability of a rock sample sample measured using gas is given given by the follo&ing follo&ing euation
&here m
'
cc per sec at pressure
a L 5 ) P
' ' ' ' '
cc per sec at # atmosphere cp cm cm atm
rive the above euation starting &ith generali8ed arcy euation.
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Reservoir Engineering Lab
,ata 3or +as P!r$!a$!t!r
5ength of core sample "cm$ ' Core diameter "cm$ '
P# "atm$ P inlet
P"atm$ P outlet
Pm "atm$ P average
P "atm$ P ' P# %P Paverage
% - %
"cc>sec$
: "arcy$
: ( #7"mdarcy$
Reservoir Engineering Lab
EXPERIMENT @
API +RAVITY MEASUREMENT
Ob:!'ti"!;
To determine the )PI gravity of oil by using hydrometer and a nd picknometer. Apparat#s;
Hydrometer 1igham Pycnometer
Basi' T4!ory;
etermination of density or specific gravity of petroleum liuid is important for the calculation of volume and &eight of the petroleum. +or crude oil, gravity also sho&s the uality of the crude oil. +urther more, it is also a sign of the composition and the heat of combustion of a particular petroleum material.
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Reservoir Engineering Lab
Sp!'i3i' gra"ity a&( API gra"ity
2pecific gravity is defined as the ratio of a liuid density to the density of &ater, both measured at the same pressure and temperature.
+or *nglish Jnit system! Oo ' lb>cubic lb>cubic foot oil O& ' lb>cubic lb>cubic foot &ater 2ometimes, specific gravity of a liuid is stated as 2/ at
. This is to say that both
density &ere measured at <7 o+ "#9.9< oC$ and atmospheric pressure. +or petroleum industry, is is also kno&n that the unit )PI gravity "o)PI$ is defined as follo&s!
4ith
This unit is al&ays used to state the specific gravity of stock tank oil. *(ample The density of crude oil in a stock tank at <7 o+ is 97.7 lb>cu.ft. Calculate the 2/ and the )PI gravity of the oil. #.
Calculate 2/ 2/ ' 97.77><.-= ' 7.D7#=
.
Calcul Calculate ate )PI )PI gravit gravity y )PI ' #3#.9>7.D7#= % #-#.9 ' 39 o
Note: API = “American Petroleum Petroleum Institute”, is a national commercial commercial institution that leas the !etroleum inustr" inustr" in stanari#ing e$ui!ments e$ui!ments %or rilling an !rouction& !rouction& It 'as establishe in ()*+&
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Reservoir Engineering Lab
M!as#r!$!&t o3 API by #si&g 4y(ro$!t!r2
Apparat#s
#. Hydromet ometer er . /rad /radua uate ted d cyli cylind nder er a. Cylinder Cylinder must must be tall enough enough to provide provide at 9 mm space space bet&een bet&een the the bottom bottom of of the floating hydrometer and the base of the cylinder. b. The minimum diameter of the cylinder must be at least 9 mm greater than the diameter of the bulb of the hydrometer, -. Thermo rmometer 3. #97 #97 Petr Petrole oleum um Measu Measurin ring g Tab Table le
M!as#ri&g pri&'ip!
This method is based on the principle that a floating body in a liuid &ill have part if its body submerge in the liuid. The depth of the submerged part is inversely proportional to density or gravity of the liuid. In this principle the floating body is the )PI Hydrometer &hich is a hydrometer &ith )PI gravity scale. E=p!ri$!&ta Pro'!(#r!
#. Pour a sample into into the the graduated graduated cylinder cylinder.. Prevent Prevent any any formation formation of of bubble. bubble. Put Put the hydrometer into the sample. . 2tir the sample sample &ith the thermo thermometer meter,, record record the thermo thermometer meter reading. reading.
-. Take Take out the the thermometer thermometer and and leave the the hydrometer hydrometer freely freely floating floating in the the sample. sample. Push the hydrometer into the sample for about scale unit and then release it. 4ait until the hydrometer is e(actly stationary. 6ead the scale to the nearest 7.777# for 2/, and to the nearest 7.9 for o)PI. Procedure to read the hydrometer scale #. +or transpa transparent rent liuid liuid % meniscus meniscus across across the the liuid liuid surface surface . +or opaue opaue liuid liuid 0 above above the meniscus, meniscus, and use meniscu meniscuss correction correction Table Table #. 3. 6ecord the temperature temperature again. again. Calculate Calculate the the average average temperature. temperature. If the the temperature temperature difference is greater than 7.9 oC from the first reading, the measurement of gravity need to be repeated.
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Reservoir Engineering Lab
R!s#t
#. Make correction correction on hydr hydrometer ometer readings readings by converti converting ng the )PI )PI to standard standard .gravity .gravity o "<7 +$ using Table 9 )2TM #97 . 6eport 6eport the the correct corrected ed hydro hydromet meter er reading reading as o)PI.
,!t!r$i&atio& o3 API +ra"ity
Sa$p!
T!$p!rat#r! o3 Sa$p! o.
API +ra"ity 3ro$5Hy(ro$!t!r)
% = %
S+ +ra"ity 5 0>0 o. ) R!3!r ASTM 5 tab! *)
API +ra"ity r!3!r ASTM 5 tab! @)
Reservoir Engineering Lab
,!t!r$i&atio& o3 ,!&sity
Pro'!(#r! ;
#. Thoroughly clean the pycnometer and stopper &ith a cleaning fluid, rinse &ell &ith distilled &ater. +inally rinse &ith acetone and dry. . 4e 4eight ight the dry pycnometer pycnometer &ith stopper stopper at room temperature
-. +ill the the pycnomet pycnometer er &ith liuid liuid at the the same same room room temperatur temperature. e. 3. Put on on the stopper stopper and be be sure there there is no gas bubble bubble inside, inside, and then then dry the e(terior e(terior surface of the pycnometer by &iping &ith a lint%free cloth or paper. 9.
4eight ight the filled filled pycno pycnomet meter er..
-!ig4t o3 !$pty Py'&o$!t!r 5g$)
-!ig4t o3 Py'&o$!t!r 3i 6it4 t4! i<#i( 5g$)
Vo#$! o3 t4! i<#i( 5 '')
,!&sity o3 t4! i<#i( 5g$>'' )
/#!stio&
#. @ther than than bubble bubble problem, problem, state other other problems problems encountered encountered during during the measurem measurement ent &hich may lead to error in the measurement.
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Reservoir Engineering Lab
EXPERIMENT
R!ati"! ,!&sity o3 +as!s P#rpos!
!
etermination of relative density of gases
E<#ip$!&t
!
2chilling *ffusiometer
T4!ory
etermining the density of gas relative to air at the same ambient temperature and pressure.
γ gas
=
δ gas δ air
M!t4o( o3 M!as#r!$!&t
This method based on the /raham 5a& of diffusion. This method based on the fact that the times taken by eual volumes of gases to flo& under the same conditions through a small orifice are proportional to the suare roots of the densities of gases.
6elative .ensity
=
ρ gases ρ air
=
, t gases , t air
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Reservoir Engineering Lab
&here t ' ' times taken by eual eual volumes volumes of gases to flo&, "second$. E<#ip$!&t
2chiling *ffusiometer " +igure #$ 2top 4atch Thermometer Mat!ria
)ir ;itrogen @(ygen Carbon io(ide @ther gases
I&str#'tio&
#. +ill the the outer cylinder cylinder &ith &ith &ater at ambien ambientt temperature temperature and open the the side cock to let the &ater enter in the measuring tube. . Pour &ater &ater in the the outer cylinder cylinder till till the level level arrives above above the upper upper mark mark of the measuring tube. -. The central central -%&ay -%&ay cock being being closed, closed, blo& blo& air through through the the side cock cock till the the &ater reaches the lo&er mark on the measuring tube. 3. 4a 4ait it the fe& minutes minutes to euili euilibrate brate the &ater &ater and insuff insuffled led aim tempera temperatures. tures. 9.
@pen the the -%&ay stopco stopcock ck and let let high ten ten the &ater &ater level through through the the calibrated calibrated orifice orifice from the lo&er to the upper mark. Take the elapsed time.
<. 6epeat 6epeat the test several several times times at the same temperat temperature. ure. 2hould 2hould the time time values values differ differ from more than >9 secondsG Check the calibrated orifice eventually clean it &ith the help of compressed air. =. Calculate Calculate the average average obtained obtained value, value, accordin according g to the numbe numberr of tests carried carried out. out. D. Clean the the measuring measuring tube tube &ith the the gas to be tested. tested. 6un 6un several several tests on the same temperature as this one of the used air and calculate the average flo& time. 6epeat several determinations &ith air at the same temperature after having completely blo&ed out the gas. This operation serves to check the eventual presence for impurities.
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Reservoir Engineering Lab
/#!stio&
#. etermine etermine the relative relative density density of gases. gases. Make Make conclusion conclusion based based on differen differentiatio tiation n of molecular &eight of gases &as used. . If e(periment e(periment conducted conducted at high high temperature, temperature, &hat &hat happen happen for gas flo&ing flo&ing time and and value of gas densityG
+as
Ti$!
1
+as +ra"ity
*
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A"!rag!
Reservoir Engineering Lab
Valve #
Valve
/asket
Jpper mark
@uter cylinder
Measuring tube
Inner cylinder
5o&er mark
+igure #! Cross section of 2chilling *ffusiometer
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Reservoir Engineering Lab
EXPERIMENT
SMO9E POINT 20
OBJECTIVE
To determine the smoke point of oil samples such as ?et )%# and kerosene kerosene by burning the oil samples in an enclosed smoke smoke point lamp so that the height of the fire tongue can be estimated.
*20
APPARATUS
2moke point lamp, &ick, beaker, oven and graduated cylinder. 6efer +ig. #.
THEORY>INTRO,UCTION
Please refer )2TM #- for this information and other publish materials.
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Reservoir Engineering Lab
METHO,OO+Y
#.
Clean ean an and dry dry the the &i &ick from im impureriti ities.
.
2oak oak the the &ic &ick k in into the the oil oil sam samp ple to be tes teste ted. d.
-.
Inse Insert rt the the # #9 mm mm so soaked aked &ick &ick into into lam lamp co cover. er.
3.
+ill +ill the the lamp lamp &ith &ith 7 ml oil oil sam sampl ple. e. The The lam lamp p shou should ld have have alrea already dy clea cleane ned d and dried.
9.
2cre 2cre& & the the lamp lamp cove coverr to to the the sock socket et.. Cut Cut &ick &ick to leve levell &it &ith h the the &ick &ick guid guide. e. Pull the &ick to < mm above the end of the &ick guide.
<.
5ight the &ick for 9 minutes at flame height appro(imately #7 mm.
=.
)d?ust &ick "e(tent the &ick$ until the flame produces smoke.
D.
6edu 6educe ce the the len lengt gth h of of the the &ick &ick slo& slo&ly ly unti untill sm smoke oke dis disap appe pear ar..
E.
Measu Measure re the the ma( ma(im imum um heig height ht of the the flam flamee ton tongu guee in in mm mm "th "this is is the the smo smoke ke point$. The measurement should be be done at point 1 as sho&n by +ig .
#7. #7.
6epe 6epeat at the the e(peri e(perime ment nt - tim times es for for each each sam sampl plee to get get the the accu accurat ratee aver averag agee value. Jse Jse ne& ne& clea clean n and and dry dry &ic &ick k for for ne& ne& oil oil samp sample le..
##.
RESUT
a$
Measu Measure re smok smokee poi point ntss for for dif diffe fere rent nt oil oil sam sampl ples. es. Comp Complet letee Ta Table ble . .
b$
Calculate the average smoke points for each sample.
,ISCUSSION
a$
4rite rite an an e(p e(pla lana nati tion on on the the resu result lt of of the the measu measure red d smok smokee poi point nt for for the the different samples.
b$
4hat are the characteristics the can be inferred from the different values of smoke points for different samples.
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Reservoir Engineering Lab
CONCUSION
2tate the conclusion of this e(periment.
2ample # ;o.
2ample Height of flame tongue " mm$
;o.
)verage
)verage
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Height of flame tongue " mm$
Reservoir Engineering Lab
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