powerpoint presentation petrophysics

8/16/2019 Powerpoint Presentation Petrophysics

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Nuclear Magnetic Resonance (NMR)

Core Analysis

Petrophysics presentation on:

Members:

Naomi Jobson

Xavier luna

Gregory Men!etishi

Jubril A"e!anmbi#eth $ari!ari

George %&eoma %srael

M#c Petroleum 'ngineering

**+* #ession ,ecturer: -r. Pe"ro/ -ia0


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Content

1. Overview What is NMR Historical development The importance of NMR Basic principles

2. Methodology and

nstr!mentation". NMR #ogging nterpretation

$. %ore &i'e (istri)!tion

*. %ermea)ility

+. #ow Resistivity Reservoir

,val!ation

-. NMR Hydrocar)on Typing

. /oncl!sion

0. Recommendations

1. References


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1hat is NMR2

*. Nuclear Magnetic Resonance

. %t is a techni3ue use" in

4ormation evaluation (core

analysis/ that is to "etermine

porosity/ permeability an" poresi0e "istribution.

5. %t e6amines the behaviour o4

nuclear spins by manipulating

them in magnetic 4iel"s.

7igure *b: Geospec NMR %nstrument

7igure *a: 8vervie o4 Geospec e3uipment.


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9istorical -evelopment

*. %t as "iscovere" in *;< an"

recogni0e" in *=s

. ,e" to the "evelopment o4 Nuclear>

Magnetic>,ogging (NM,) tools in the

early *


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The Importance of NMR

B NMR provi"es in4ormation about the "i44erent 4lui"s present

in the 4ormation (ater an" "i44erent oil types have

"istinctive NMR signals).B Non "estructive / both in organic an" inorganic materials/

that is human+reservoir system.B Can measure all petrophysical "ata system.B ery economical to buil"up an" to use.

? D transverse rela6ation time o4 the pore

4lui" as measure" by a

CPMG (CPMG: names) se3uence.

?* D the measure" longitu"inal rela6ation

time o4 the pore 4lui"


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%nstrumentation an" Metho"ology.

B Magnet 4or generating magnetic 4iel"s.B 9y"rogen ions 4rom the hy"rogen contenting compoun"s

in the core. e.g. 98 9E E 89>

B Magnetic moment .B 'lectrical supply in the magnetic core.

7igure . Far magnet

Magnetic 4iel"s


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B atomic nuclei are charge" particles .B 9y"rogen contain atomic nuclei.B atomic nuclei possess a 3uantum mechanical

property calle" spin angular momentum .B ?his property ma!es the nucleus spins aroun"

an imaginative a6is .

B the spinning motion causes a magnetic momentthat is co>linear ith the "irection o4 the spin

a6is .B in the absence o4 an e6ternally applie"

magnetic 4iel"/ the in"ivi"ual magnetic moment

align ran"omly an" stable .

B %n the present o4 an e6ternal magnet 4iel"/ themagnetic moment align parallel an" antiparallel

to the magnetic 4iel" Fo.


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B *9 nuclei (protons) contain a high magnetic moment/

that ma!es it the i"eal nucleus 4or NMR logging an"

NMR imaging in ra"iology.B ?he energy "i44erent beteen the parallel an"

antiparallel magnetic moment 4orms a net bul!

magneti0ation that align parallel to Fo.B NMR techni3ue can only "etect the net bul!

magneti0ation arising here.

B 7or a signal to be "etecte" by the NMR ,ogging/ a

state o4 resonance nee"s to be attaine".B Resonance means alternating absorption an"

"issipation o4 energy .B 'nergy absorption arises 4rom ra"io4re3uency (R7)

perturbation .B 'nergy "issipation is me"iate" by rela6ation

processes.B R7 can be consi"ere" as another magnetic 4iel" o4

strength F* perpen"icular to F as shon in 7igure ;

Methodology and Instrumentation cont’d


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7igure 5b: #hoing #pin>'cho (or 9ahn>'cho)

7igure 5a : Magnetic spin


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NMR Logging Interpretation

*. ? "istributions provi"e some very use4ulin4ormation about reservoir>roc! an" >4lui"

properties an" it constitutes the basic

outputs "isplaye" on an NMR log.

. ? "istributions compute" 4rom NMR echo

"ata are use" to compute NMR total/

boun">4lui"/ an" 4ree>4lui" porosities/ an"

also are use" 4or permeability an"

reservoir>3uality estimation.

5. %n ater>saturate" roc!s/ ? "istributions

are 3ualitatively lin!e" to pore>si0e

"istributions.

;. ?he short ? values in a ? "istribution are

associate" ith signals 4rom ater in small

pores/ meanhile the longer ? values

matches to signals 4rom ater in larger

pores.


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Determination of Porosity and Pore

Size Distriution from NMR Core

*. Core in4ormation receive" about the basic pore si0e "istribution4rom the NMR core analysis/ enable a number o4 use4ul

petrophysical parameters to be easily calculate".

. ?he integral o4 all the ?s (area un"er the curve) gives the total

porosity hen compare" to the signal 4rom a !non re4erence.

5. A4ter centri4uging the core an" repeating the NMR measurements/

the integral o4 the secon" "ata is the irre"ucible 4lui" (F%)/ hilethe "i44erence beteen the to is the 7ree 7lui" %n"e6 (77%).

7igure ;: -etermination o4 F% an" 77% 4rom

log plot


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NMR Core Permeaility !nalysis

B Fase" on theoretical mo"els

B ?he 7ree>7lui" or Coates mo"elB 7ormations containing ater an"+or hy"rocarbons

B ?he Mean ? mo"el ("evelope" by #hlumberger)

B 7ormations containing ater only.

B Re3uires matching ? to a H"ynamicI pore si0e estimator.

B Mercury %n&ection Capillary Pressure (ResultDsynthetic Pc curve)

ba

XXms BVI

FFI C KmD

⋅

=

1.

φ

( )k m D C T L M a

b

( ) . .=

2 1 0 0

φ


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"#aluating from NMR

Calibration o4 mo"el

7igure =b: Coates Mo"el

an" #-R Mo"el

7igure =a: ,ayout o4

NMR ,ogging tool.


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Lo$ Resisti#ity Reser#oir "#aluation

*. A Gul4 o4 Me6ico ell is

use" as an e6ample toillustrate the evaluation

o4 a lo resistivity

reservoir using MR%,.

. ?he reservoir core as

ma"e up o4 a massive>

me"ium>to 4ine graine"san"stone.

5. ?he upper portion o4

the reservoir (0one A)

ha" higher resistivity

than the loer portion

(0one F)/ beteen *>

.= ohm>m.

;. ?he "ecrease in

resistivity in the loer

portion o4 the reservoir

as the main concern.

7igure


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Core %ydrocaron Typing Simulation

7igure @a: ater an" light oil simulation

e44ects on ? "istribution.

7igure @b: ater/ light oil an" gas

7igure @c: '44ect o4 viscosity

an" ettability o4 the oil

signal in a ? "istribution

*. %t is "i44icult to "istinguish the native oil>base" mu" 4iltrate because o4 the mi6ture o4

these to !in"s o4 oil an" their NMR

signals.

. 1hen ater/ light oil/ an" gas occupy the

same pore system in the 4ormation roc!s

(4ig. )/ both light oil an" gas coul" be

"etecte" through their ,ongitu"inal contrast

(?*).

5. #imulation result shos that roc!s are

probably not completely oil>et some are

o4 interme"iate an"+or mi6e" ettability.

;. %4 a 4ormation contains mi6e" ettability/

"i44erentiating beteen oil an" ater

presents "i44iculty (4rom simulation).


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Conclusions

NMR logging as 4irst intro"uce" "uring the *precession measurements in the 'arthIs

magnetic 4iel".

?he proper use o4 NMR technology re3uires goo" communication

beteen oil an" service companies to ensure that logging ob&ectives an"

"ata>3uality e6pectations are met.

?here are uni3ue an" poer4ul stan"alone NMR 4ormation evaluation

metho"s available 4or evaluating 4lui" types/ saturations/ an" porosities

in comple6 reservoirs. A""itionally/ NMR logs provi"e estimates o4

boun"> an" 4ree>ater volumes/ oil viscosities/ an" 4ormation

permeabilities sub&ect to the caveats.

%n comple6 reservoirs/ NMR an" other log "ata shoul" be integrate" ith

all other available reservoir in4ormation (e.g./ especially "ata 4rom 4lui">

sampling an" pressure tools an" core "ata) to provi"e the most accurate

picture o4 the reservoir.


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Annie Cottis/ Peter ,oc! K ?ony Farro/ (**)/ NMR Basics to Expert

User, eat!er"or#$abs.com. Presentation ma"e at Geological #ociety

,on"on/ Picca"illy.

Fen"el/ P./ (*)/ Journal o4 Magnetic Resonance. %pi&'ec!o atte&(atio&b) #i""(sio& i& &o&'(&i"orm "ie$# *ra#ie&ts. ol. =*=.

George/ R. C./ et al (*)/ NMR Lo**i&* +ri&cip$es a pp$icatio&s.

Lnite" #tates o4 America: 9alliburton 'nergy #ervices.

References


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?han! you 4or listening

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