petroleum

1. Petroleum and its Formation
Petroleum Exploration and Extraction
(MRT327-3)
Group No-05
1

2. What is Petroleum?
Petro  Rock
Oleum  Oil
Petroleum is a broad term that combination of
organic liquid and gases that is formed after
kerogen is heated and compressed over long
periods of time.
Figure 01 : Surface-Crude oil2

3. Composition of Petroleum
Hydrocarbons
Naphthalene (30-60%)
Alkanes / Paraffin (15-60%)
Aromatics (3-30%)
Asphaltic(remainder)
Non Hydrocarbons
Sulphur
Nitrogen
Oxygen
metals
Types of Petroleum
• Solid hydrocarbon – Asphalt
• Liquid hydrocarbon – Crude oil
• Gas hydrocarbon – Methane, butane and propane
3

4. Usages of Petroleum
• Transportation
 Petrol and diesel
• Industrial power
 Diesel and gasoline are used in gas turbines to produce electricity.
• Heating and lighting
 Oil is also used to produce electricity
 Kerosene
• Lubricants
 Greases-sophisticated machinery in use in factories & vehicles.
• Petro-chemical industry
 chemical fertilizer, synthetic fiber, synthetic rubber, nylon, plastics,
pesticides and insecticides, perfumes, dyes, paints, carbon black
and Sulphur.
• Use of by-products.
4

5. Petroleum producers
• OPEC(Organization of the Petroleum Exporting
Countries)
 13 countries
 36% of world’s oil production
 Saudi Arabia is the biggest producer
• OECD(Organization for Economic Co-operation and
Development )
 24% of world’s oil production
 The USA is the major producer
• The states of the former Soviet Union
 15% of world’s oil production
Figure 02: Middle east countries
5

6. Conditions for formation of fossil fuels
• High Organic content.
• Burial of organic material.
• Reducing conditions – little or no free O2
• It preserves organic matter.
• Coal and Petroleum diverge from here.
Figure 03 : Fossil fuel formation
6

7. Formation of Petroleum
• Formed 50-500 million years ago.
• Any dead plant or animal can form petroleum over
million of years.
• Five major processes involved,
1. Deposition
2. Burial
3. Diagenesis
4. Catagenesis / Cracking
5. Reservoir formation
7

8. Deposition and Burial
• Mostly in Marine environment.
• High amount of nutrition.
 Algae, plankton, and zooplankton.
• Huge amount of sedimentation.
• Organic resin mix with rock sediments.
• Land area - Low sedimentation.
Figure 05 : PlanktonFigure 04 : Kimmeridge clay- Black shale 8

9. Diagenesis
• Under high temperature & high pressure.
• Chemical bond in biomass breaks.
• Reform new heat, pressure stable compositions.
• Long chain bio polymers initially break,
 Proteins or carbohydrates
• Forms rocks by mixing with sediments
• Condense into new polymers
• H, N, O and S get removed
• Aromatization occur
• Rings stack on each other and forms,
 Kerogen – Waxy material
 Bitumen – Tar like material
9

10. Types of kerogen and their
hydrocarbon potential
10

11. Catagenesis
• Kerogen is a solid waxy mixture of organic matter in
sediments from which petroleum is released.
• Burial depth increased
• Temperature and pressure increased
• Kerogen produces oil
Figure 06 : Crude oil 11

12. Metagenesis
• Burial depth further increases.
• Pressure and temperature further increased.
• Methane get released.
• Petroleum migration to traps begins.
Oil window - is a temperature dependent interval in
the subsurface where oil is generated and expelled
from the source rocks.
Gas window - is a temperature dependent interval in
the subsurface where gas is generated and expelled
from the source rocks.
12

13. Physical conditions of each phases
Figure 07 : Diagenesis Figure 08 : Catagenesis Figure 09 : Metagenesis
13

14. Petroleum system
• Source Rock
 A rock with abundant hydrocarbon-prone organic matter
• Reservoir Rock
 A rock in which oil and gas accumulates:
o Porosity –space between rock grains in which oil accumulates
o Permeability - passage-ways between pores through which oil and
gas moves
• Seal Rock
 A rock through which oil and gas cannot move
effectively
o Mudstone
o Clay stone
14

15. • Migration Route
 Avenues in rock through which oil and gas moves
from source rock to trap
 Two types
• Primary migration – within the source rock
• Secondary migration – beyond the source rock
15

16. • Petroleum traps
 The structural and stratigraphic configuration that
focuses oil and gas into an accumulation
• Three types,
 Structural traps - Deformation of reservoir rock
 Stratigraphic traps - Deposition of reservoir rock
 Combined traps – combination of structural and
stratigraphic traps
Figure 10 : Petroleum traps
16

17. • Structural traps are 3 types,
 Anticline trap
 Fault trap
 Salt dome trap
• Stratigraphic traps can be categorized into 2 types,
 Primary traps
o Variations in facies that developed during sedimentation.
 Secondary traps
o Variations that developed after sedimentation.
Figure 11 : Fault trap Figure 12 : Salt dome trap 17

18. Reservoir formation
• High pressure and temperature inside the earth.
• Hot gas and oil are less dense.
• Sand stone and lime stone are permeable.
• Shale impermeable.
• The oil and gas get trapped.
Figure 13 : Movement of oil
and gas
Figure 14 : Petroleum reservoir
formation 18

19. Thank you!
19

20. Group members
• Rupasinghe R.A.L.D.P (UWU/MRT/15/047)
• Rashad M.S.M (UWU/MRT/15/049)
• Gamlath J.G.V.I. (UWU/MRT/15/053)
• Nirujan B. (UWU/MRT/15/055)
20