Lecture 02 Porosity(1)

8/17/2019 Lecture 02 Porosity(1)

1/71

POROSITY


2/71

Definition: Porosity is the fraction of a rock that

is occupied by voids (pores).

Discussion Topics

• Origins and descriptions

• Factors that effect porosity

• Methods of deterination

RESERVOIR POROSITY


3/71

ROCK MATRIX AND PORE SPACE

Rock matrix Pore space

Note different use of “matrix”b !eo"o!ists and en!ineers


4/71

Porosity: The fraction of a rock that is

occupie !y pores

b

mab

b

p

V

VV

V

V

Porosit

POROSIT" DE#INITION

• Porosity is an intensive property describing the

f!uid storage capacity of rock


5/71

ROCK MATRIX AND PORE SPACE

Rock matrix #ater Oi" and$or !as


6/71

O$%ECTI&ES

To pro'ie an unerstanin( of

) The concepts of rock *atri+ an porosity

) The ifference !et,een ori(ina- .pri*ary/ an

inuce .seconary/ porosity) The ifference !et,een tota- an effecti'e porosity

) 0a!oratory *ethos of porosity eter*ination

) Deter*ination of porosity fro* ,e-- -o(s


7/71

C0ASSI#ICATION O# ROCKS

"#D$M#%T&'

R o c k % f o r m i n !

p r o c e s s

S o u r c e o f

m a t e r i a "

$%#O*"

M#T&MO'P+$,

&o"ten materia"s in

deep crust and

upper mant"e

'rsta""i(ation

)So"idification of me"t*

#eat+erin! and

erosion of rocks

exposed at surface

Sedimentation, buria"

and "it+ification

Rocks under +i!+

temperatures

and pressures in

deep crust

Recrsta""i(ation due to

+eat, pressure, or

c+emica"" acti-e f"uids


8/71

SEDIMENTAR" ROCKS• '"astics

•'arbonates

•E-aporites


9/71

'./STI' /ND '/R0ON/TE RO'1S

'"astic Rocks

,onsist Priari!y of "i!icate Minera!s

&re ,!assified on the -asis of:

rain "i/e Minera! ,oposition

'arbonate Rocks

,onsist Priari!y of ,arbonate Minera!s

(i.e. Minera!s 0ith a ,O &nion roup)

1iestone Predoinate!y ,a!cite (,a!ciu

,arbonate2 ,a,O2)

Do!oite Predoinate!y Do!ostone (,a!ciu

Magnesiu ,arbonate2 ,aMg(,O3)4 )

34


10/71

Re"ati-e /bundances

Si"tstone

and s+a"e

)c"astic*3456

Sandstone

and con!"omerate

)c"astic*

3776

.imestone and

do"omite

3786

SEDIMENTAR" ROCK T"PES1


11/71

"andrains

,!ayMatri5

,heica!,eent

Quartz Feldspar Rock Fragments

Quartz Calcite

Hematite

IlliteKaoliniteSmectite

/-era!eSandstone

/-era!e&udrock)S+a"e*

&!!ocheica!rains

,heica!,eent

Microcrysta!!ineMatri5

Calcite

FossilsPelloidsOolitesIntractlasts

Calcite

/-era!eSparr

.imestone/-era!e&icritic

.imestone

'"astic Rocks 'arbonate Rocks

'omparison of 'ompositions of '"asticand 'arbonate Rocks


12/71

rain"i/e ,!assification for ,!astic "edients

%ae Mi!!ieters Microeters

-ou!der ,obb!ePebb!eranu!e

6ery ,oarse "and,oarse "andMediu "andFine "and6ery Fine "and

,oarse "i!tMediu "i!tFine "i!t6ery Fine "i!t,!ay

7289

4;

77

4<8.;

8.4;8.


13/71

/-era!e Detrita" &inera" 'omposition

of S+a"e and Sandstone

&inera" 'omposition S+a"e Sandstone

,!ay Minera!s

>uart/

Fe!dspar

'ock Fragents

,arbonate

Organic Matter2+eatite2 andOther Minera!s

9: )6*

2:

8

;5

2

;2

5 )6*

95

7:%75

75

;7

;7

(odified fro -!att2


14/71

S/NDSTONE './SSI


15/71


16/71


17/71

ORI2INS O# POROSIT" IN

C0ASTICS AND CAR$ONATES.2enetic C-assification/

) Pri*ary .ori(ina-/

) Seconary .inuce/

.2enera--y *ore co*p-e+ than pri*ary porosity/


18/71

PRIMAR" .ORI2INA0/ POROSIT"

) De'e-ope at eposition

) Typifie !y

3 Inter(ranu-ar pores of c-astics or

car!onates

3 Intercrysta--ine an fenestra- pores of car!onates

) 4sua--y *ore unifor* than inuce porosity


19/71

SECONDAR" .IND4CED/ POROSIT"

) De'e-ope !y (eo-o(ic processes aftereposition .ia(enetic processes/

) E+a*p-es

3 2rain isso-ution in sanstones or car!onates

3 &u(s an so-ution ca'ities in car!onates

3 #racture e'e-op*ent in so*e sanstones1 sha-es1an car!onates


20/71

S/NDSTONES POROSITY TYPES

Inter!ranu"ar )Primar*

Disso"ution

&icropores


21/71

#ACTORS T5AT A##ECT POROSIT"

) Partic-e sphericity an an(u-arity

) Packin(

) Sortin( .'aria!-e (rain si6es/

)Ce*entin( *ateria-s

) O'er!uren stress .co*paction/

) &u(s1 isso-ution1 an fractures

PRI&/RY

SE'OND/RY )dia!enetic*


22/71

RO?NDNESS /ND SPERI'ITY

O< './STI' GR/INS

i!+

S P E R I '

I T Y

.oA

Ver

/n!u"ar /n!u"ar

Sub%

/n!u"ar

Sub%

RoundedRounded

#e""%

Rounded

RO?NDNESS

Porosity

P o r o s i t y


23/71



) Packin(


)Ce*entin( *ateria-s



PRI&/RY

SE'OND/RY )DI/GENETI'*


24/71

1ine of Traverse

(using icroscope)

,eent

Matri5(c!ays2 etc.)

Tangentia! ,ontact

"utured ,ontact

1ong ,ontact

,oncavo,onve5,ontact

GR/IN P/'1ING IN S/NDSTONE

)modified from 0"att, 7@JF*

T+is Examp"e

Packing Pro5iity @ 78A

Packing Density @ 8.=

7 Types of rain ,ontacts

Packing Pro5iity

Packing Density

& easure of the e5tent to?hich sedientary partic!esare in contact ?ith theirneighbors

& easure of the e5tent to?hich sedientary partic!es

occupy the rock vo!ue


25/71

'?0I' P/'1ING O< SPERESPorosit K 8J6


26/71

Porosity Ca-cu-ations 7 4nifor*

Spheres

) $u-k 'o-u*e 8 .9r/: 8 ;r :

) Matri+ 'o-u*e 8

) Pore 'o-u*e 8 !u-k 'o-u*e 7 *atri+ 'o-u*e

2

r 82


27/71

69842F

7r J

r 2 $8r J

Vo"ume0u"k Vo"ume&atrixVo"ume0u"k

Vo"ume0u"kVo"umePorePorosit

2

22

π

π


28/71

RO&0I' P/'1ING O< SPERESPorosit K F4 6


29/71



) Packin(


) Ce*entin( *ateria-s



PRI&/RY



30/71

Packing of T?o "i/es of "pheresPorosit K 786


31/71

Grain%Si(e Sortin! in Sandstone

6ery 0e!!

"orted

0e!!

"orted

Moderate!y

"orted

Poor!y

"orted

6ery Poor!y

"orted

SORTING


32/71

,hange of ,oposition ,hange of "i/e

,hange of "hape ,hange of Orientation

,hange of Packing

"and

"ha!e

#o!ian

F!uvia!

"!o? ,urrent

Fast ,urrent

'iver

-each

TYPES O< TECT?R/. '/NGES SENSED

0Y TE N/1ED EYE /S 0EDDING


33/71


34/71

STS97/%8F%::57 &ississippi Ri-er De"ta, .ouisiana, ?S/ October 7@J5


35/71

STS:J8%4F7%:F@ Se"en!a Ri-er De"ta, .ake 0aka", Russia &a 7@@4


36/71



) Packin(


) Ce*entin( *ateria-s



PRI&/RY



37/71

DI/GENESIS

,arbonate,eented

Oi!"tained

Diagenesis is the Post

Depositiona! ,heica! andMechanica! ,hanges thatOccur in "edientary 'ocks

"oe Diagenetic #ffects $nc!ude

,opactionPrecipitation of ,eentDisso!ution of Frae?ork rains and ,eent

The #ffects of Diagenesis May#nhance or Degrade 'eservoir >ua!ity

0ho!e ,oreMisoa Foration2 6ene/ue!a P+oto b # /ers

D?/. POROSITY IN S/NDSTONE


38/71

D?/. POROSITY IN S/NDSTONE

&/TRIC


39/71

S/NDSTONE 'O&POSITION,


40/71

POROSITY IN S/NDSTONE

>uart/rain

Pore

"canning #!ectron Micrograph%orph!et "andstone2 Offshore &!abaa2 *"&

Porosity in "andstoneTypica!!y is 1o?er ThanThat of $dea!i/ed Packed"pheres O?ing to:

6ariation in rain "i/e

6ariation in rain "hape

,eentation

Mechanica! and ,heica!

,opaction

P+otomicro!rap+ b R. 1u!"er


41/71


"canning #!ectron MicrographTordi!!o "andstone2 %euEuen -asin2 &rgentina

Pore Throats in"andstone May

-e 1ined 0ith & 6ariety of ,eent Minera!sThat &ffectPetrophysica!

Properties

P+otomicro!rap+ b R. 1u!"er


42/71


"canning #!ectron Micrograph

%orph!et Foration2 Offshore &!abaa2 *"&

Pores Provide the

6o!ue to "tore

+ydrocarbons

Pore Throats 'estrict

F!o? through pores

Pore

T+roat

' S


43/71

Secondar E"ectron &icro!rap+

'"a &inera"s in Sandstone Reser-oirs,/ut+i!enic '+"orite

Burassic Norp+"et SandstoneOffs+ore /"abama, ?S/ )P+oto!rap+ b R. 1u!"er*

Occurs as T+in'oats on Detrita"Grain Surfaces

Occurs in Se-era"Deep" 0uriedSandstones #it+i!+ Reser-oir=ua"it

Iron%Ric+Varieties React#it+ /cid

3 7: µm


44/71

E"ectron P+otomicro!rap+

'"a &inera"s in Sandstone Reser-oirs,


45/71

INTERGR/N?./R PORE /ND &I'ROPOROSITY

$ntergranu!ar Pore

Microporosity

ao!inite>uart/Detrita!rain

$ntergranu!ar Pores

,ontain +ydrocarbonF!uids

Micropores ,ontain$rreducib!e 0ater

-ackscattered #!ectron Micrograph,arter "andstone2 -!ack 0arrior -asin2

&!abaa2 *"& )P+oto!rap+ b R. 1u!"er*

'"a &inera"s in Sandstone Reser-oirs


46/71

'"a &inera"s in Sandstone Reser-oirs,/ut+i!enic 1ao"inite

"econdary #!ectron Micrograph

,arter "andstone%orth -!o?horn ,reek Oi! *nit

-!ack 0arrior -asin2 &!abaa2 *"&

"ignificant Pereabi!ity'eduction

+igh $rreducib!e 0ater "aturation

Migration of Fines

Prob!e

(Photograph by '.1. ug!er)


47/71

DISSO.?TION POROSITY

Thin "ection Micrograph P!ane Po!ari/ed 1ight

&vi!e "andstone2 %euEuen -asin2 &rgentina

Disso!ution of

Frae?ork rains

(Fe!dspar2 for

#5ap!e) and

,eent ay#nhance the

$nterconnected

Pore "yste

This is "econdaryPorosity

Pore

>uart/ Detrita!

rain

Partia!!y

Disso!ved

Fe!dspar

P+oto b R. 1u!"er


48/71

DISSO.?TION POROSITY

"canning #!ectron Micrograph

Tordi!!o Foration2 %euEuen -asin2 &rgentina

Partia!!y

Disso!ved

Fe!dspar

Disso!ution Pores

May be $so!ated andnot ,ontribute to the

#ffective Pore "yste

P+oto b R. 1u!"er

' i f ' iti f '" ti


49/71

"andrains

,!ayMatri5

,heica!,eent

Quartz Feldspar Rock Fragments

Quartz Calcite

Hematite

IlliteKaoliniteSmectite

/-era!eSandstone

/-era!e&udrock)S+a"e*

&!!ocheica!rains

,heica!,eent

Microcrysta!!ineMatri5

Calcite

FossilsPelloidsOolitesIntractlasts

Calcite

/-era!eSparr

.imestone/-era!e&icritic

.imestone

'"astic Rocks 'arbonate Rocks

'omparison of 'ompositions of '"asticand 'arbonate Rocks


50/71

I"es Gambier

Tuamotu /rc+ipe"a!o


51/71

&a"di-e Is"ands


52/71


53/71


54/71

'/R0ON/TES POROSITY TYPES

Interpartic"e

Intrapartic"e

Intercrsta"

&o"dic

Pores -et?een Partic!es or rains

Pores 0ithin $ndividua! Partic!es or rains

Pores -et?een ,rysta!s

Pores Fored by Disso!ution of an$ndividua! rain or ,rysta! in the 'ock


55/71

$nterpartic!e $ntrapartic!e $ntercrysta! Mo!dic

Fenestra! "he!ter ro?thFrae?ork


56/71

'/R0ON/TE POROSITY % EC/&P.E

Thin section icrograph p!anepo!ari/ed !ight

"ackover Foration2 &!abaa)P+oto!rap+ b D' 1opaska%&erke"*

&o"dicPores

• Due to disso!ution

and co!!apse of ooids

(a!!ocheica! partic!es)

• $so!ated pores

• 1o? effective porosity

• 1o? pereabi!ity

-!ue areas are pores.

'a"cite

Do"omite

&o"dic

Pore

'/R0ON/TE POROSITY EC/&P.E


57/71

'/R0ON/TE POROSITY % EC/&P.E

Thin section icrograph

"ackover Foration2 &!abaa

-!ack areas are pores.

)P+oto!rap+ b D' 1opaska%&erke"*

• ,obination pore syste

• Mo!dic pores fored through

disso!ution of ooids (a!!ocheica!

partic!es)

• ,onnected pores

• +igh effective porosity

• +igh pereabi!ity

&o"dic

Pore

Interpartic"e

Pores

&o"dic and

Interpartic"e Pores


58/71

PORE SPACE

C0ASSI#ICATION

.In Ter*s of #-ui Properties/


59/71

PORE7SPACE C0ASSI#ICATION

) Tota- porosity1 φt 8

) Effecti'e porosity1 φe 8

&o-u*e$u-k

PoreVolumeTotal

&o-u*e$u-k

Pore Spacected Interconne

• Effecti-e porosit M of !reat importancecontains t+e mobi"e f"uid


60/71

COMPARISON O# TOTA0 AND

E##ECTI&E POROSITIES

) &ery c-ean sanstones : φe → φt

) Poor-y to *oerate-y ,e-- 7ce*ente

inter(ranu-ar *ateria-s: φt ≈ φe

) 5i(h-y ce*ente *ateria-s an *ostcar!onates: φe < φt


61/71

MEAS4REMENT O# POROSIT"

) Core sa*p-es .0a!oratory/

) Openho-e ,ire-ine -o(s


62/71

>uar t/(Fr ae?or k)

"a!!Por es

$so!atedPor es

1ar ge2$nter connectedPor es

,!ay"ur f aces$nter !ayer s,!ay1ayer s$r r educib!eor $obi!e0ater +ydr ationor -ound0ater

+ydr ocar bonPor e6o!ue

"tr uctur a !(O+)0ater 'ockMatr i5 Tota!Por osity%eutr on1ogTota!Por osityDensity1og &bso!uteor Tota!Po r osityOvenDr ied,or e &na!ysis Por osity+uidityDr ied,or e &na!ysisPor osity

,api!!ar y0ater 6"ha!e"andstonePor osity Measur edby6ar iousTechn iEues

>uar t/(Fr ae?or k)

"a!!Por es

$so!atedPor es

1ar ge2$nter connectedPor es

,!ay"ur f aces$nter !ayer s,!ay1ayer s$r r educib!eor $obi!e0ater +ydr ationor -ound0ater

+ydr ocar bonPor e6o!ue

"tr uctur a !(O+)0ater 'ockMatr i5 Tota!Por osity%eutr on1ogTota!Por osityDensity1og &bso!uteor Tota!Po r osityOvenDr ied,or e &na!ysis Por osity+uidityDr ied,or e &na!ysisPor osity

,api!!ar y0ater 6"ha!e"andstonePor osity Measur edby6ar iousTechn iEues

S/NDSTONE POROSITY &E/S?RED

0Y V/RIO?S TE'NI=?ES

>uart/(Frae?ork)

"a!!Pores

$so!atedPores

1arge2 $nterconnectedPores

,!ay "urfaces $nter!ayers

,!ay1ayers

$rreducib!e or $obi!e 0ater

+ydration or -ound 0ater

+ydrocarbonPore 6o!ue

"tructura!(O+ %) 0ater

'ockMatri5

Tota! Porosity %eutron 1og

Tota! Porosity Density 1og

&bso!ute or Tota! Porosity

OvenDried ,ore &na!ysis Porosity+uidityDried

,ore &na!ysis Porosity

,api!!ary

0ater

6"ha!e

)modified from Es"in!er and Pe-ear, 7@JJ*


63/71

IN#ORMATION #ROM CORES=

) Porosity

) 5ori6onta- per*ea!i-ity toair

) 2rain ensity

) &ertica- per*ea!i-ity to air

) Re-ati'e per*ea!i-ity

) Capi--ary pressure

) Ce*entation e+ponent .*/

an saturation e+ponent .n/

Standard /na"sis Specia" 'ore /na"sis

/""oAs ca"ibration of Aire"ine "o! resu"ts

CORIN2 ASSEM$0"


64/71

PD' 'utters


65/71

COMIN2 O4T O# 5O0E

>IT5 CORE $ARRE0

>5O0E CORE


66/71

#+o"e 'ore P+oto!rap+,&isoa “'” Sandstone,

Vene(ue"a

>5O0E CORE

P+oto b # /ers


67/71

SIDE>A00 SAMP0IN2 24N

'ore bu""ets

'ore samp"e

A00 CORIN2 TOO0


68/71

SIDE>A00 CORIN2 TOO0

'orin! bit

Samp"es


69/71

>5O0E CORE ANA0"SIS 's?

P042S OR SIDE>A00 CORES

>5O0E CORE

) Pro'ies -ar(er sa*p-es

) $etter an *ore consistent representation of

for*ation

) $etter for hetero(eneous rocks or for *ore

co*p-e+ -itho-o(ies

#O.E 'ORE /N/.YSIS -s


70/71

) S*a--er sa*p-es

) 0ess representati'e of hetero(eneous for*ations

) >ithin @ to 9 of ,ho-e cores for *eiu*7to hi(h7

porosity for*ation

) In -o,7porosity for*ations1 φ fro* core p-u(s tens

to !e *uch (reater than φ fro* ,ho-e cores

) Sca-ar effects in fracture reser'oirs

P.?GS OR SIDE#/.. 'ORES

P.?GS OR SIDE#/.. 'ORES


71/71

'ORE P.?G

Lecture 02 Porosity(1)

Documents