Oleh:
RAGIL PRATIWI GEOSERVICES
Introduction to Petroleum Geochemistry and its Significance in Hydrocarbon Exploration and How to Get Your Scholarships Abroad?
UNDIP SHARING SESSION Semarang, 20th June 2015
Course Outline 1
st
Introduction to Petroleum Geochemistry
2n
d
How to Get Your Scholarships Abroad?
Course Outline
• Introduction
• Theories on Origin of Petroleum
• Petroleum Geochemistry: Introduction
• Organic Matters in Source Rocks
• Source Maturation and Petroleum Generation
• Geochemical Laboratory Analysis
• Introducing Biomarkers
Recommended References Waples, D.,W., 1985, Geochemistry in Petroleum Exploration, International Human
Resources Development Corporation, Boston.
Hunt, J.M., 1996, Petroleum Geochemistry and Geology, W.H. Freeman and Company, 2nd
ed., San Francisco.
Peters, K.E. and Moldowan, 1993, Biomarker Guide – Interpreting Molecular Fossils in
Petroleum and Ancient Sediments, Prentice-Hall, Inc., Englewood Cliffs.
Peters, K.E., Walters, C.C., Moldowan, J.M., 2005, The Biomarker Guide, Vol. 1: Biomarkers
and Isotopes in the Environment and Human History, 2nd ed., Cambridge University
Press, Cambridge.
Peters, K.E., Walters, C.C., Moldowan, J.M., 2005, The Biomarker Guide, Vol.2: Biomarkers
and Isotopes in Petroleum Exploration and Earth History, 2nd ed., Cambridge
University Press, Cambridge.
Articles on Biomarkers in AAPG (American Assoc. of Petroleum Geologists) Bulletin,
Organic Geochemistry
Papers on Biomarkers in IPA (Indonesian Petroleum Assoc.) Proceedings
Theories on Origin of Petroleum
Abiogenic
Petroleum was formed from deep carbon deposits, perhaps relating to the formation of the Earth, and that petroleum migrate upward from the mantle
(Thomas Gold, 1999)
Biogenic
Pooled oil and gas in porous reservoirs can only be explained by its origin in thermally mature, organic-rich, sedimentary source rocks
(Wallace Dow, 2002)
Satyana (2014)
Petroleum Geochemistry
Geochemistry is the application of chemistry to the study of rocks and fluids.
(Selley, 1985 : Elements of petroleum geology)
The application of chemical principles to the study of the origin, migration, accumulation, and alteration of petroleum and the use of this knowledge in the exploration and production of oil and gas.
(Hunt, 1996 : Petroleum geochemistry and geology)
Satyana (2014)
What can petroleum geochemistry do ?
• evaluate physical and chemical properties of oil and/or gas in basin
• determine how many oil and/or gas families are present in basin
• expect source/s of oil and/or gas in basin
• evaluate presence, quality, and maturity of source rocks in basin
• determine volumetric of oil and/or gas generated, migrated, and accumulated in basin,
• evaluate migration pathways of oil and/or gas in basin
• predict fluid type (oil/gas/water) containing in prospect ahead of drilling
• predict in-reservoir alteration (e.g. biodegradation) and its trend
• understand intra-field/-reservoir petroleum variations
• etc.
Satyana (2014)
What can petroleum geochemistry do ?
Clayton and Fleet (1991)
in Satyana (2014)
How we have ignored petroleum geochemistry ?
Satyana (2014)
a. What people know (in lesser detail): reservoir, trap, seal, kitchen, migration.
b. Too much evaluation on reservoir and trap. Too less evaluation on hydrocarbon charging (evaluation on kitchen and migration are too over-simplified).
c. One with strong interest, knowledge, and experience on geochemistry is scarce.
Trilogy of Exploration Success
Satyana (2014)
Needs integration of
Geology, Geophysics, and Geochemistry
“3G”
and always see them historically
After Murris (1984) in Satyana (2014)
Source Rock
• Sedimentary rocks that are, or may become, or have been able to generate petroleum are source rocks
Tissot and Welte (1984)
• Sedimentary rocks commonly contain minerals and organic matter with the pore space occupied by water, bitumen, oil, and / or gas
Peters and Cassa (1994)
Petroleum, Hydrocarbon and Non Hydrocarbon
• Petroleum is a complex mixture of gas, liquid, and solid hydrocarbons and nonhydrocarbons occurring naturally in the earth
• Hydrocarbon is commonly used in the petroleum industry to indicate crude oil or natural gas. In the chemical sense, hydrocarbons are compounds containing only carbon and hydrogen.
• Nonhydrocarbons contain elements in addition to hydrogen and carbon. For example, NSO compounds contain nitrogen, sulfur, or oxygen, and porphyrins contain metals such as vanadium or nickel.
Peters and Cassa (1994)
Brooks (1987) in Satyana (2014)
Bitumen
Fraksi Bitumen dan Crude Oils
Waples (1985)
Kerogen
• Kerogen (from kerosene generator) is defined as the organic
component of source rocks that is insoluble in common organic
solvents and aqueous alkali (NaOH solution). It is the parent of
petroleum.
The soluble portion of the organic matter is termed bitumen or total
soluble extract (TSE)
• Kerogen is of complex biological origin; it is derived from dead
organisms whose organic remains survive the early stages of
diagenesis and lithification.
Satyana (2014)
After Clayton and Fleet (1991)
Source Rock Screening
Source Rock Screening
Rock Eval - Pyrolysis
Time
TOC & Rock Eval - Pyrolysis
• TOC (Total Organic Carbon) : a measurement the organic richness of
sedimentary rocks
• S1 : the amount of free hydrocarbon
• S2 : the amount of the remaining hydrocarbon potential
• S3 : the amount of carbon dioxide released during pyrolysis
• Hydrogen Index (HI) : the hydrogen richness = S2/TOC x 100%
• Oxygen Index (OI) : the oxygen richness = S3/TOC x 100%
Miles (1989)
Rock Eval - Pyrolysis • Tmax
represents the temperature at which the maximum amount of hydrocarbons degraded from kerogen are generated
• The Production Index (PI)
is also in part indicative of the degree of thermal maturity (Peters, 1986)
PI = S1 / (S1+S2)
PI < 0.4 = immature
PI : between 0.4 and 1.0 = mature
PI > 1.0 are indicative of overmature
Miles (1989)
Ibrahimbas and Riediger (2004)
Quantity, or amount of organic matter
Quality, or type of organic matter
Peters and Cassa (1994)
Exercises 1
From data above, can you please explain :
1. Which section that could be source rocks?
2. What kind of fluids that have been generated?
3. How mature is that rock?
Ibrahimbas and Riediger (2004)
Tipe III immature source rocks
The Application of Rock Eval Pyrolysis for Kerogen Type Analysis
Peters and Cassa (1986)
REP Application
REP Application
Source Maturation and Petroleum Generation
Mahmoud, et all (2006) in in Satyana (2014)
Source Maturation and Petroleum Generation
Merrill (1991) in Satyana (2014)
Source Maturity Analysis POLLEN / SPORE COLOUR "STANDARD"
MUNSELL COLOUR STANDARDS (MATTE FINISH)
THERMAL
MATURITY
SPORE
COLOUR
APPROXIMATE
CORRELATION TO
OTHER SCALES
IMMATURE
MATURE MAIN
PHASE OF
LIQUID
PETROLEUM
GENERATION &
PRESERVATION
DRY GAS
OR BARREN
HU
E
7.5y
7.5y
7.5y
5y
2.5y
10y,r
10y,r
10y,r
10y,r
10y,r
VA
LU
E
9
9
9
8
8
6
5
4
3
2.5
CH
RO
MA
4
8
10
12
12
10
6
DO
MIN
AN
T
WA
VE
LE
NG
TH
(µ
M)
31
57.5
68.5
82.5
80.5
68.5
61
50
30
16
MU
NS
EL
L
PR
OD
. N
O.
14,479
14,481
12,992
13,618
14,253
12,424
12,382
17,209
15,814A
15,978
Lemigas (1-5)
1
1+
2-
2
2+
3-
3
3+
4-
4
5
Thermal Alteration Index (TAI)
Batten
(1-7)
1
1/2
2
2/3
3
3/4
4
5
4/5
5/6
6
7
% Ro.
Vit.
0.20
0.25
0.33
0.40
0.51
0.65
0.77
1.00
1.70
3.00
1.30
2.40
0.85
Staplin
(1-5)
1
1.5
2
2.5
3
4
5Compiled from Collins 1990, and LEMIGAS versions
of Munsell colour standards chart, 1997, 2008
SCI
Colourless
(1) Colourless-
pale yellow
(2) Pale yellow
(3) Lemon
yellow
(4) Golden
yellow
(5) Orange
(6) Orange
brown
(7) Brown
(8) Dark brown
(9) Dark brown
black
(10)
Collins 1990
(1-10)
Colours are based on the Munsell colour solid (right), where each colour is described by a hue, value and chroma such as 5R 6/4. Hue is assigned a letter and divided into ten segments, 5 being the middle of a hue and 10 the boundary between one hue and the next. Value represents the shade of a colour from 1 (light) to 10 (dark) and chroma is the degree of saturation, from grey to vivid.
WHITE
BLACK
CHROMA
(SATURATION)
YELLOW-RED
YELLOWRED
RED-
PURPLE
PURPLE
PURPLE BLUE
BLUE
BLUE-GREEN
GREEN-
YELLOW
GREEN
BR
IGH
TN
ES
S
HUE
y,rr
r,p
p
p.bb
b,g
g
g.y
y
very
light
purple
very lightpurple
very
pale
purple
purp
lish
wh
ite
wh
ite
light gre
y
ligh
tpurp
lish g
rey
pale
purple
light
purple
greyish
purple
purp
lish
gre
y gre
y
brilliant
purple
brilliantpurple
moderate
purple
strong
purple
vivid
purple
dark
purp
lish g
rey
dark
gre
y
purp
lish
bla
ck
bla
ck
very dark
purple very
dusky
purp
le
very deep
purple
deep
purple
dark
purple
dusky
purple
vivid purpleDimensions of the
colour solid
Purple section of
the colour solid
1997 2007
1
1+
2-
2
3-
3
3+
4-
4
5
2+
The most common methods to understand the maturity of source rocks are :
1. Vitrinite reflectance
2. Spore color index
Batten (1981) mod. by Geoservices
Vitrinite Reflectance
Microscopic Analysis of Organic Remains
Spore Colour Index and Kerogen Typing
palynology.geoscienceworld.org
