TM 2209

PETROFISIKA
Semester II – 2021/2022
Pahala Dominicus Sinurat
Ivan Kurnia
Ketentuan Umum
• PR & materi suplemen via Edunex (+ MS Teams)
• Pertanyaan -->
• MS Teams
• ivan_kurnia@itb.ac.id
• PR & tugas diserahkan pada waktu yang telah
ditentukan
• Presensi mandiri di SI-X
Evaluasi (Tentatif)
• Pekerjaan rumah, Kuis : 15%
• Lab/Praktikum : 15%
• Ujian Tengah Semester : 35% (bahan ujian:
W1-W7)
• Ujian Akhir Semester : 35% (bahan ujian: W9-
W15)
• Kehadiran tidak diperhitungkan
Pustaka Acuan
• Petroleum Reservoir Engineering: Physical Properties (J. W.
Amyx, D. M. Bass, Jr., and R. L. Whiting: 1960, 1988).
• Petrophysics: Theory & Practice of Measuring Reservoir Rock &
Fluid Transport Properties (D. Tiab dan E. C. Donaldson: 2004,
2nd ed.)
• Properties of Reservoir Rocks: Core Analysis (R. P. Monicard:
1980)
• Petroleum Reservoir Rock and Fluid Properties (Abhijit Y.
Dandekar, 2013, 2nd Edition, CRC Press)
• Coring and Core Analysis Handbook (G. Anderson: 1972).
• Fundamentals of Reservoir Rock Properties (N. Alyafei: 2021)
• Dll.
 PE ITB - Student Outcomes
1. An ability to apply knowledge of mathematics, science, and
engineering
2. An ability to design and conduct experiments, as well as to analyze
and interpret data
3. An ability to design a system, component, or process to meet desired
needs with realistic constraints
4. An ability to function on multidisciplinary teams
5. An ability to identify, formulate, and solve engineering problems
6. An understanding of professional and ethical responsibility
7. An ability to communicate effectively
8. The broad education necessary to understand the impact of
engineering solutions in a global, economic, environmental, and
societal context
9. A recognition of the need for and an ability to engage in life-long
learning
10. A knowledge of contemporary issues
11. An ability to use the techniques, skills, and modern engineering tools
necessary for engineering practice
Petrofisika: Definisi & Sejarah
Properti
Batuan
Petrofisika
Interaksi
Batuan-Fluida

1859 1936 1942

Col. Drake Hassler Archie

1856 1927 1936 1941

Darcy Kozeny Schlumberger Leverett
Petrofisika – Ilmu Terkait & Aplikasi

Production
Drilling Eng. Eng. Reservoir Eng.

Petrophysics
Fluid & Well
Geophysics Logs & Core Analysis
Analysis

Geology
Topik-Topik yang Dibahas
• Batuan reservoir & perangkap hidrokarbon
• Pori-pori dan porositas
• Permeabilitas absolut
• Saturasi fluida
• Sifat kebasahan batuan
• Tekanan kapiler
• Permeabilitas efektif dan relatif
• Kompresibilitas
• Sifat hantar arus listrik (electrical properties) batuan berpori yang
berisi fluida
• Rock Typing
• Digital Petrophysics
Litologi Reservoir &
Perangkap Hidrokarbon
 Kilas Balik – Geologi Fisik

• Klasifikasi batuan
• Mineral pembentuk batuan
• Batuan sedimen
• Energi fosil
Klasifikasi Batuan
% dari kerak
Jenis Deskripsi
bumi
Beku (Igneous) Intrusi & ekstrusi lelehan magma yang 20
mengalami pendinginan
Metamorf Transformasi (mekanik, panas, kimiawi) 14
batuan beku & sedimen
Sedimen Hasil dari proses mekanik & kimia 66
terhadap batuan lain & bangkai biologis
Batuan Reservoir = Porous, Permeable
Sandstone Carbonate
• Silica grain: quartz, • Calcite, dolomite
feldspar • Pore space: inter- &
• Consolidated, loosely intra-granular,
consolidated, dissolution, fracture
unconsolidated

New play: Fractured shale

Clean vs Dirty Rocks (Clay Content)
Heterogenitas
Pada umumnya reservoir bersifat heterogen:
✓ Sedimentasi/deposisi
✓ Lingkungan pengendapan
✓ Diagenesa
✓ Facies.
Skala Batuan Reservoir

Reservoir
Blok Rokan

Suardin, 2021
 Minas

Masduki et al., 2020

 Contoh Skala Giga dan Mega

Skala :
Mega scale :
25 meter

Giga scale : Skala :

200 meter
? Sandstone
?
Giga scale : ? ?
Carbonate Buildup
 Contoh macro scale Whole cores
Sandstone

Core plug

Common low resistivity low contrast lithofacies observed in the MTJDA include
Bioturbated Muddy Sandstone (Sbm), Rippled Heterolithic (Hr) and Bioturbated
Heterolithic (Hb). Occasionally these intervals are also associated with Bioturbated
Sandstone (Sb) and Rippled Sandstone (Sr).
Contoh macro scale: whole cores/conventional
CARBONATE Carbonates CARBONATE

Diameter ≈ 4 inches
Contoh micro scale - thin section
(warna biru = pori-pori)
Crocker, Donaldson, Marchin (1983)
Comparison and Analysis of Reservoir Rocks and Related Clays
SEM Pictures to Identify
Production Problems
Holub et al., 1974
From Macro to Micro
Via X-Ray CT Imaging

Jackson et al., 2019

ODC-BY 1.0
 Skala Batuan Reservoir
Giga (>100 m)

Mega (10-100 m)
Uncertainty Makro
(cm-m)
Mikro
 Petroleum System

Source Rock - Genesis

Migration

Trap + Seal

Accumulation = Reservoir
 Reservoir Seal

Seal

Sedimen Materi Organik

P & T ↑↑ Source
 Jebakan Hidrokarbon

Struktural Stratigrafi
• Hasil proses tektonik • Perubahan fasies akibat
• Bentuk: fold/lipatan, proses sedimentasi
fault/patahan, diapiric • Lebih kompleks karena
(e.g. intrusi kubah melibatkan pergantian
garam) lingkungan endapan
Jebakan Hidrokarbon
Simple convex trap

Simple convex trap

(differential thickness)

Permeability trap

Amyx et al, 1960

Jebakan Hidrokarbon
Pinchout trap

Fault trap

Piercement trap

Amyx et al, 1960

 TM 2209
PETROFISIKA
Semester II – 2021/2022
Prof. Pudji Permadi
Pahala Dominicus Sinurat, PhD
Ivan Kurnia, PhD
Reviu Kuliah 1
• Petrofisika: sejarah, ruang lingkup, keterkaitan dengan disiplin dan
sub-keilmuan
• Litologi reservoir: batu pasir (sandstone) & gamping (karbonat),
lempung (shale)
• Sistem petroleum: sumber, migrasi, penjebakan, akumulasi
• Skala batuan Reservoir
Deskripsi Padatan Penyusun
Batuan Reservoir
 Sumber Sampel Batuan
toh macro scale Whole cores
Sandstone Whole Core Outcrop Drill Cuttings

Core plug

ontrast lithofacies observed in the MTJDA include

(Sbm), Rippled Heterolithic (Hr) and Bioturbated Peksa et al, 2015
these intervals are also associated with Bioturbated
ndstone (Sr).
Bentheimer Sandstone (Peksa et al, 2015)

Loose packing, hematite Weathered feldspar grains

between grains
Bentheimer Sandstone (Peksa et al, 2015)
Whole Core - Slab

Heriott-Watt Reservoir Engineering p 7-28, p 8-3

7
Sidewall Sampling Gun

Core bullets

Formation rock

Core sample

8
Sidewall Coring Tool

Coring bit

Samples

9
Deskripsi Batuan Reservoir
Ukuran Butiran
Size Limit (mm) Class
256-2048 Boulders
64-256 Cobbles Gravel
2-64 Pebbles
1/16 – 2 Sand Sand
1/512 – 1/16 Silt
Mud
< 1/512 Clay
Deskripsi Batuan Reservoir
Distribusi Ukuran Butiran

Berea Sandstone (Tiab & Donaldson, 2004)

Deskripsi Batuan Reservoir
Material Sementasi & Lempung

Hanya
pembanding

Mineral
lempung
(Clays)
Deskripsi Batuan Reservoir
Routine Core Analysis
Klasifikasi Dunham untuk Batuan Karbonat

Depositional Texture Recognizable Depositional

Components Not Bound Together During Deposition Original Components Texture
Contains Mud Lacks Mud, Bound Together Not Recognizable
(clay and silt size particles Grain- During Deposition
Mud Supported Grain Supported
<10 % >10 % Supported
Grains Grains Crystalline
Mudstone Wackestone Packstone Grainstone Boundstone Carbonate

Prof. Maggard – NEXT Schlumberger

16
Aplikasi Deskripsi Batuan
• Strategi Pemboran
• Perlakuan untuk sampel batuan
• Karakterisasi Reservoir
Pori-Pori Batuan Reservoir
Pori-pori
• Rongga, ruang dalam batuan yang dapat ditempati oleh fluida

Butiran/ Luas Total (Bulk) =

Padatan PxL

Luas Pori =
Luas Total – Luas Butiran
Pori-Pori Batuan Reservoir
Effective Porosity:
Interconnected + Dead-end

Pore throat

Dead-end

Pore body
Pori-Pori Batuan Reservoir
Absolute Porosity
Interconnected + Dead-end
+ Isolated

Isolated
Ukuran Pori-Pori
Ukuran Pori-Pori

Peksa et al, 2015

Faktor yang Mempengaruhi Ukuran &
Sebaran Pori-Pori
• Keseragaman ukuran butiran
Faktor yang Mempengaruhi Ukuran &
Sebaran Pori-Pori
D-ratio Φ SD Scale
1.0 – 1.6 0.0 – 0.35 v wl srtd
1.6 – 2.0 0.35 – 0.5 wl srtd
2.0 – 4.0 0.5 – 1 mod srtd
4.0 – 16.0 1–2 p srtd
> 16.0 >2 v p srtd
(Folk, 1965)
Faktor yang Mempengaruhi Ukuran &
Sebaran Pori-Pori
• Susunan butiran (packing)
Faktor yang Mempengaruhi
Ukuran & Sebaran Pori-Pori
• Sementasi & konsolidasi
Faktor yang Mempengaruhi
Ukuran & Sebaran Pori-Pori
• Angularity/Roundedness
Faktor yang Mempengaruhi Ukuran &
Sebaran Pori-Pori
• Keseragaman ukuran butiran (sorting)
• Susunan butiran (packing)
• Derajat sementasi atau konsolidasi
• Kompaksi
• Rekahan
• Pelarutan & reaksi karbonat
Berea Sandstone Elgin Sandstone
Porosity = 0.219 Porosity = 0.240
Permeability = 363 mD Permeability = 3,484 mD

(Tiab & Donaldson, 2004)

Diskusi Penutup
 TM 2209
PETROFISIKA
Semester II – 2021/2022

Prof. Pudji Permadi, PhD

Pahala Dominicus Sinurat, PhD
Ivan Kurnia, PhD
Reviu Pertemuan 2
• Sumber sampel batuan
• Deskripsi padatan penyusun batuan reservoir
• Pori-pori & faktor yang mempengaruhinya
Porositas
Porositas

(Peksa et al, 2015)

Solids
Pore
Diameter
Length
Porositas: Absolut & Efektif
• Porositas Absolut atau • Porositas Efektif
Total
Porositas & Kompleksitas Batuan

• Jenis padatan
• Variasi ukuran
• Sifat fisik tiap padatan

(Nanz, 1954)
Porositas & Kompleksitas Batuan

Bulk
Solids Fluids

Grains Clay Clay-

quartz,feldspar Minerals
Bound W HC
Water
silt, mud

φ-effective

φ-total
Penentuan Porositas

Core Analysis Well Logging

Bulk Volume • Sonic Log
• Gravimetric • Neutron Log
• Caliper • Density Log
Pore Volume
• Boyle’s Law Single Cell
• Saturation
• Hg injection
• Solvent extraction
Porositas dari Well Logs

Respon log:
• Litologi
• Fluida dalam pori-pori

Alyafei, 2021
Hg Immersion

𝑚𝑎𝑠𝑠 𝐻𝑔 𝑑𝑖𝑠𝑝𝑙𝑎𝑐𝑒𝑑
𝐵𝑉 =
𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝐻𝑔 𝑎𝑡 𝑇

API RP40
Buoyancy Method with Fluids

API RP40
Hg Volumetric Displacement

API RP40
Boyle’s Law Apparatus

API RP40
Core Analysis – Bulk Volume
Method Principle Advantages & Limitations
Immersion Gravimetric + samples could be preserved
(Archimedes’ principle) + high accuracy
- Trapped air leads to high error
- Not suitable for p-uncons & vuggy

Hg Displacement Displaced Hg volume + very rapid

+ samples could be preserved
- Trapped air leads to high error
- Not suitable for p-uncons & vuggy

Caliper Direct measurement + Rapid & simple

+ Not suitable for irregular samples
Core Analysis – Pore Volume
Method Principle Advantages & Limitations
Dry Grain Volume Measurement on + fast
powdered sample - not viable for several minerals
- Assuming unchanged state during
drying
Boyle’s Law Cell P1V1 = P2V2 + samples are undamaged
(grain volume or + quick, simple, repeatable
direct void volume) + suitable for GV of irregular & vuggy
samples
- High maintenance for calibration
Liquid Saturation Gravimetric + direct PV measurement
- Slow
- Limited accuracy
Porosity from Digital Imaging (Arns et al., 2005)
Porosity from Digital Imaging (Arns et al., 2005)
Averaging Porosity

φ1, h1
φ2, h2

φ3, h3
Aplikasi Porositas
• Kalibrasi antara RCA – well logs
• Korelasi dengan properti lainnya
• Karakterisasi reservoir
• Estimasi volume minyak & gas bumi
Glover, 2008
Pore Space Visualization of Carbonates
(Lucia, 1983)
Pore Space Classification of Carbonates
(Lucia, 1983)
Core Sample of Vuggy Carbonate
(He et al., 2020)
Pore Space Characters of Carbonates (Arns et al., 2004)
Pore Space Characters of Carbonates (Arns et al., 2004)
Pore Space Characters of Carbonates (Arns et al., 2004)
Pore Space Characters of Carbonates (Arns et al., 2004)
 TM 2209
PETROFISIKA
Semester II – 2021/2022

Prof. Pudji Permadi, PhD

Pahala Dominicus Sinurat, PhD
Ivan Kurnia, PhD
Reviu Pertemuan 3
• Porositas: Definisi, Pengukuran, Kompleksitas
• Porositas dari Core Analysis vs Log Interpretation
Saturasi Fluida
Etimologi & Definisi
Etimologi saturasi
• KBBI: kejenuhan
• MW: saturate = to fill completely with something that pervades, to
load to capacity

Saturasi fluida: fraksi volume suatu fluida dalam pori-pori batuan

Porositas & Saturasi Fluida
Bulk Volume
Solids Total Porosity

Grains Clay Clay-

quartz,feldspar Minerals
Bound W HC
Water
silt, mud
Saturasi Fluida

VB =
100 bbl

Vp = 20 bbl
Sw = 0.25, Vw = 5 bbl
So = 0.75, Vo = 15 bbl
Saturasi Fluida

FWL
Faktor yang Mempengaruhi Saturasi Fluida
• Porositas
• Distribusi ukuran pori
• Kandungan dan jenis clay
• Sifat kebasahan batuan
• Tegangan antarmuka (IFT) air-minyak
• Posisi vertikal di dalam reservoir
• Masa produksi
Saturasi Fluida

Before Migration After Migration After Production

Sumber Data Saturasi

Core Analysis Well Logging

• Routine CA • Resistivity Log
• Special CA
Saturasi Fluida – Well Log
Saturasi Fluida – Core Analysis

• Retort method
• Solvent extraction
• Centrifuge method
Saturasi Fluida – Core Analysis
Retort method
• Temperatur tinggi untuk menguapkan air & minyak
• Langsung mengukur Vo & Vw

Alyafei, 2021
Saturasi Fluida – Core Analysis
Retort method
• Discrepancies due to high T
Saturasi Fluida – Core Analysis
Solvent Extraction
• Penguapan
solvent/pelarut toluene,
gasoline, naphtha
• Direct Sw measurement
• Clean, undamaged core

Amyx, 1960
Saturasi Fluida – Core Analysis
Centrifuge
• High centrifugal force
• Consolidated core
• Solvent assisted
• Direct Sw measurement
Saturasi Fluida – Core Analysis
Perubahan Kondisi Saturasi pada Sampel Batuan

• Invasi lumpur pemboran

• Perubahan tekanan drastis
Kondisi Saturasi pada Sampel Batuan
Kennedy, Van
Meter, and Jones
(1954) WBM

OBM
Kegunaan Data Saturasi dari Sampel Batuan
• Kemungkinan tidak representatif sebagai acuan saturasi HC
sebenarnya
• Tren Sw/So dari core membantu penentuan WOC & GOC
• Penentuan kandidat lapisan produktif
• Korelasi dengan properti lainnya
Saturasi Fluida & Porositas
Swi v ф
100
90
80
70
60
Swi, % 50
40
30
20
10
0
0 5 10 15 20 25 30 35
ф, %
Saturasi Fluida - Well Log
 TM 2209
PETROFISIKA
Semester II – 2021/2022

Prof. Pudji Permadi, PhD

Pahala Dominicus Sinurat, PhD
Ivan Kurnia, PhD
Reviu Minggu 4 – Saturasi Fluida
Permeabilitas
Etimologi & Definisi
• MW:
(v) permeate = to diffuse through; to pass through the pores or interstices of
(adj) permeable = capable of being permeated, esp. having pores or openings
that permits fluids to pass through

• KBBI: Kemampuan suatu bahan meloloskan partikel dengan menembusnya

• API: sifat fisik media berpori yang mengukur kemampuan/kemudahan

media dalam mengalirkan fluida
Permeabilitas
Permeabilitas ≈ Konduktivitas

𝑉
• Electric current: 𝐼 = =𝑉 ×𝐶
𝑅
𝑑𝑇
• Heat transfer: 𝑞𝑥 = −𝑘𝐴
𝑑𝑥

𝑘 𝑑𝑝
• Laju alir: 𝑞 = 𝐴
𝜇 𝑑𝐿
Attempts in Defining Flow Equation
Reservoir Pore Spaces
Hukum Darcy (1856)
ℎ1 − ℎ2
𝑄 = 𝐾𝐴
𝐿

𝑘 𝑑𝑝 𝑞𝜇
𝑞= 𝐴 𝑘=
𝜇 𝑑𝐿 𝑑𝑝
𝐴
𝑑𝐿

• 100% saturasi, fluida tunggal

• Fluida Newtonian, incompressible
• Aliran Laminer
• Steady-state
• Iso-thermal
• Tidak ada reaksi antara fluida & batuan
Unit Permeabilitas

1 darcy = 0.9869 x 10-12 m2

= 1000 md
Faktor yang Berpengaruh terhadap Permeability
• Ukuran dan susunan butiran
• Kandungan dan jenis clays
• Ukuran pore throat
• Vuggy pores (ukuran & susunan)
• Fractures (ukuran & network)
Hubungan k dengan Properti Lain

• k versus  : eksponensial
• k versus Swc : power law
• Contoh persamaan empirik :
✓ Timur: k = ab/(Sw)c
✓ Coates: (k)0.5 = 1002(1–Swi)/Swi
Porosity-Permeability

Tiab, D., & Donaldson, E. C. (2004).

Porosity-Permeability

Tiab, D., & Donaldson, E. C. (2004).

Permeability - Swc
Darcy’s Law for Horizontal, Linear Flow
Darcy’s Law for Radial Flow
 Permeability of Combined Layers
• Linear flow in parallel layers

Alyafei, 2021
 Permeability of Combined Layers
• Linear flow in series of layers

Alyafei, 2021
 Permeability of Combined Layers
• Radial flow in parallel layers

Alyafei, 2021
 Permeability of Combined Layers
• Radial flow in series of layers

Alyafei, 2021
Single Fluid Permeability
Fluid Saturation = 100% -> kabsolute

• Permeability to Liquid
• Permeability to Gas
Permeability to Water (kw)
• Mendekati hukum Darcy
• Dapat terpengaruh oleh
➢ Clay swelling
➢ Fine movement
➢ Salinity
Permeability to Gas
Permeability measurement with gas:
• Compressible
• Viskositas sangat dipengaruhi tekanan
• Aliran turbulen mudah terjadi @ P/ L besar
• Difusi molekul gas @ P rendah
Gas Slippage Effect
Pada tekanan rendah, aliran gas secara signifikan
dipengaruhi oleh diffusi gas → gas slippage

Gas mengalir :
➢ Karena gradien tekanan
➢ free movement
➢ tumbukan antar molekul dan dinding pori

Mean free path dipengaruhi:

➢Ukuran molekul gas
➢Ukuran pori-pori
➢Tekanan
Gas Slippage Effect (Klinkenberg)
 Gas Slippage Effect
(Klinkenberg corrected permeability)

gradien m
.
Permeability to gas, kG

. .
. Klinkenberg Factor, b :
b = m/kL
kL

0
0
1/Prata-rata
Diskusi Penutup
Fracture Permeability
Sisi tampak samping Sisi tampak depan
w Matriks
h
Matriks
Fracture dengan tebal celah w
l
L

kfracture (darcy)= 8,45106w2

dengan w dalam satuan centimeter

kav = (kmAm + kfAf)/Abulk

 TM 2209
PETROFISIKA
Semester II – 2021/2022

Prof. Pudji Permadi, PhD

Pahala Dominicus Sinurat, PhD
Ivan Kurnia, PhD
Reviu
Sifat Kebasahan Batuan
(Rock Wettability)
Definisi
Wettability: kecenderungan batuan untuk dibasahi oleh satu dari dua fluida
(atau lebih) terpisah yang bersentuhan dengan batuan tersebut.

Tiab & Donaldson (2004)

Importance of Wettability
• Fluid saturation
• Capillary pressure
• Relative permeability
• Well log analysis
• Primary recovery
• Secondary & tertiary recovery
Wettability Spectrum

Neutral
Water-wet Oil-wet

Intermediate
0° 90° 180°
Contact Angle
Young-Dupre Eq. 𝐴 𝑇 = 𝜎𝑠𝑜 − 𝜎𝑠𝑤 = 𝜎𝑜𝑤 cos 𝜃

OIL σwo 𝜎𝑠𝑜 − 𝜎𝑠𝑤

cos 𝜃 =
𝜎𝑜𝑤
θ
σso σsw
SOLID

AT > 0 : water-wet
AT = 0 : neutral
AT < 0 : oil-wet
Interfacial Tension

Alyafei (2021)
Contact Angle: Different continuous phase

SILICA

CALCITE

Amyx et al. (1960). After Benner & Bartell (1941)

Contact Angle Measurement
• Sessile drop

From Harold Vance Dept of Petroleum Eng (2017)

 Sessile Drop - Oil-Wet Shale
(Harold Vance Dept. of PE, TAMU)
 Sessile Drop - Oil-Wet Shale
(Harold Vance Dept. of PE, TAMU)
Alat contact angle goniometer dan pendukungnya
Alat putar pipet untuk
menghisap dan
mendorong minyak

Pipet

Stand

Calcite

Quartz

Glass cell Lempeng mineral

Sessile Drop (Biolin)
Contact Angle Measurement
• Wilhelmy Plate

Advancing θ Receding θ
Tiab & Donaldson, 2004
Wilhelmy Plate (Kino Industry)
Wilhelmy Plate (Scientific Gear)
Contact Angle Measurement
• Only for polished solids (quartz & calcite)
• Useful for measurement of solute effects to wettability
• Inapplicable to reservoir rock (heterogeneity, roughness)
Spontaneous Imbibition
Fenomena imbibisi spontan

Water-wet core sample dijenuhi air dan minyak pada kondisi Swirr.

Silinder gelas

Air

Swc
(Soi = 1- Swc)

Imbibisi = proses pendesakan fluida yg tidak membasahi oleh fluida pembasah.

(kebalikan dari imbibition adalah drainage)
Spontaneous Imbibition

at Sor

at Swirr

Tiab & Donaldson, 2004

Amott Method
Alyafei (2021)
Amott Method
 Wettability of Reservoir Rocks
Anderson, 1986, after
Tiab & Donaldson, 2004 Treiber et al.(1972)

Wettability could be altered by

• Surface active compound of crude oil
• Salinity of water
• Rock minerals
• Temperature
• Fluid migration history
 Fractional & Mixed Wettability
Fractional: certain areas can be WW while others
are OW

Mixed: smaller sections of pores remain WW

while large pore becomes OW (Salathiel, 1973)
Alteration of Wettability

Abdallah et al (2007)
Wettability & Fluid Saturation

Abdallah et al (2007)
Wettability & Oil Recovery
Diskusi Penutup