Petroleum system analysis of the Upper Jurassic-Middle

PETROLEUM SYSTEM ANALYSIS OF THE UPPER
JURASSIC-LOWER CRETACEOUS SEDIMENTARY
SEQUENCES OF THE SOUTHERN MESOPOTAMIAN
BASIN, SOUTHERN IRAQ
GEOFLUID-VII 2012
Qusay Abeed 1 , Frank Strozyk 2 , Anna Uffmann 1 , Detlev Leythaeuser 1 , Ralf Littke 1
1 EMR – Energy & Mineral Resources Group - Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University,
Lochnerstrasse 4-20, D- 52056 Aachen, Germany
2 EMR – Energy & Mineral Resources Group - Geological Institute, RWTH Aachen University, Wuellnerstrasse 2, D-52056 Aachen, Germany
e-mail: qusay.abeed@emr.rwth-aachen.de

1. Introduction
2. Samples and Methods
3. Results and Discussion
4. Conclusions
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OUTLINE
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Hydrocarbons in Iraq
Historical Background
Bitumen
~ 3000 BC
INTRODUCTION
Sumerian (4000 years BC) obtained bitumen from bitumen seepages W Iraq and used it to paint
their boats “Mashhof” and the basements of their buildings
GEOFLUID-VII 2012
Bitumen seepages
Hit City, western Iraq
Ziggurrat of Ur
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Hydrocarbons in Iraq
Historical background
- The first commercial oil discovery in Iraq was the well Kirkuk No. 1.
Kirkuk oil field was discovered in Iraq on 14 October 1927.
-The first discovered oil fields in the Mesopotamian Basin southern Iraq are
Nahr Umr and Zubair anticlines by seismic survey in 1947.
- Zubair -1 and Nahr Umar-1 oil wells were drilled in February and March
1948.
GEOFLUID-VII 2012
INTRODUCTION
Well Kirkuk no. 1.
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Hydrocarbons in Iraq
Kirkuk oilfield
Zagros Sub-basin
90% of Iraq’s historical oil production has come from
just three super-giant fields:
GEOFLUID-VII 2012
Oil production
Others;
10%
Rumaila,
Kirkuk
and
Zubair;
90%
Rumaila oilfields
Mesopotamian Basin
INTRODUCTION
Zubair oilfields
Mesopotamian Basin
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Study area
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After Abeed et al., 2012
INTRODUCTION
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1. Introduction
2. Samples and Methods
3. Results and Discussion
4. Conclusions
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OUTLINE
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Samples and Methods
Thirty seven source rock core
samples from Zubair, Ratawi,
Yamama, and Sulaiy formations
analysed
Thirty one oil samples from eight
fields (Rumaila, Nahr Umr, Zubair,
Ratawi, Tuba, Luhais and Safwan)
and four reservoir horizons analysed
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SAMPLES AND METHODS
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1. Introduction
2. Samples and Methods
3. Results and Discussion
4. Conclusions
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OUTLINE
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Kerogen Type and
Maturity
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RESULTS
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Source rocks characterization
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After Abeed et al., 2011
RESULTS
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API and S content
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After Abeed et al., 2012
RESULTS
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API and S content vs.
maturity biomarkers
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After Abeed et al., 2012
RESULTS
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Oil-source rock correlation
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RESULTS
Oil origin
After Abeed et al., 2012
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Oil-source rock correlation
Hopanes identification
Peak Name
1 18α(H)-22,29,30-Trisnorneohopane
2 17α(H)-22,29,30-Trisnorhopan
3 17α(H), 21β(H)-30- Norhopane
4 17β(H), 21α(H)-30-Norhopane
5 17α(H),21β(H)-Hopane.
6 17β(H),21α(H)-Hopane.
7
8
(22S)-17α(H), 21β(H)-29-
Homohopane
(22R)-17α(H), 21β(H)-29-
Homohopane
9 Gammacerane
10
11
12
13
(22S)-17α(H), 21β(H)-29-
Bishomohopane
(22R)-17α(H), 21β(H)-29-
Bishomohopane
(22S)-17α(H), 21β(H)-29-
Trishomohopane
(22R)-17α(H), 21β(H)-29-
Trishomohopane
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RESULTS
After Abeed et al., 2012
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1D burial history, Well R-172
RESULTS
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Calibration data of well R-172
RESULTS
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1. Introduction
2. Samples and Methods
3. Results and Discussion
4. Conclusions
5. Future Work
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OUTLINE
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Source rocks characterization
1. The Cretaceous Zubair and Ratawi formations can be classified as only poor to fair petroleum
source rocks containing predominantly type III kerogen. Thermal maturity of these formations is
generally low and they have to be classified as immature to early mature.
2. The Yamama Formation is a good petroleum source rock containing type II-S kerogen. Thermal
maturity is generally early mature and peak oil generation has been reached.
3. The oldest and deepest rocks studied belong to the Sulaiy Formation. Kerogen quality and type are
difficult to evaluate due to the high thermal maturity of this stratigraphic sequence. However, a
thickness of about 200 to 300 m, high TOC contents and partly high HI values indicate that Sulaiy
Formation is an excellent petroleum source rock.
4. Molecular geochemical parameters indicate a vastly variable depositional environment of the
different source rocks. In particular the Yamama and Sulaiy formations can be regarded as typical
marine, carbonatic source rocks which were deposited under anoxic bottom water conditions.
Zubair and Ratawi formations have a greater input from higher land plants.
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CONCLUSIONS
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Crude oil characterization
CONCLUSIONS
5. Oils from four reservoir horizons from southern Iraq oil fields are characterized by a cooccurrence
of short-chain n-alkanes in high concentrations and low concentrations of long-chain
n-alkanes. In addition, CPI and Pr/Ph values are

CONCLUSIONS
9. The oils have different API values and S contents, which depend on the location and the depth
of the reservoir. The Yamama and Nahr Umr oils are the most mature, whereas the other
samples have a wider range of maturity.
10. Early generation from Type II-S kerogen, i.e. generation at low temperature, may be the
reason for the high density of some oils in the study area.
1-D Basin modelling
11. The present day temperature is the maximum burial temperature of the Upper Jurassic-
Lower Cretaceous sediments in the Mesopotamian Basin.
12. The best matching between the calibration data and the calculated geothermal gradient was
obtained using constant heat-flow of (50 mWm–2).
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GEOFLUID-VII 2012
Thank you very much for your attention !
e-mail: qusay.abeed@emr.rwth-aachen.de
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END