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