1. STRUCTURAL GEOLOGY
EUPHRATES GRABEN PETROLEUM SYSTEM
SYRIA
UNIVERSITY OF PERUGIA
PHYSIC AND GEOLOGY DEPARTMENT
PETROLEUM GEOLOGY
2014/2015
FABBRIZZI ANDREA RETTORI LUCA
2. GEOGRAPHIC LOCATION & TECTONIC SETTING
Map on the left showing simplified
tectonic setting of the Arabian
plate. The other showing location
of study region and nearby
tectonic features.
Fig.1 – Robert K. Litak, Barazangi. 1998
- Wide area of 160 x 90 km
- 6 km of extimated maximum
extension
- Convergence velocity:
18mm/y, NE verging
5. CENOZOIC REACTIVATION
Fig. 5 - Robert K. Litak, Barazangi.1998
Basin inversion in
Palmyrides fold
and thrust and
minor shortening
in NW of
Euphrates Fault
System and
Zagros
6. Fig. 6 - Brew and
Barazangi. 2001.
STRUCTURAL DEVELOPMENT
Fig. 7 - Robert K.
Litak,
Barazangi.1998
Faults cut
Precambrian
basement at 8.5 km
but they don't
extend upward
into Tertiary
section. Late
Cretaceus activity.
7. POSSIBLE OIL MIGRATION PATHWAYS
The source rock Soukhne (R‘mah) Fm syn-rift in contact with
the early Cretaceous pre-rift creates the Family 2B oil that
migrates laterally inside the Rutba and lower Shiranish Fm
reservoirs.
8. Family 2A (Shiranish Fm) accumulation in the central part of the
Miocene reservoirs and migration from SE to NW. Crude oils become
shallower with physical changes. The seal is above the fractured
Cretaceous. Family 2B juxtaposition with the Paleozoic reservoirs
locally situated in the SE, mixed with the close Silurian source rocks.
9. INTRODUCTION
PETROLEUM
SETTING
Approximately 30 oil fields
have been discovered in the
Euphrates Graben System
since ‘90s.
Recoverable reserves
discovered exceed 1 billion
barrels of oil and lesserbarrels of oil and lesser
amounts of gas.
Light oil is primarily found
in Lower Cretaceous
sandstone reservoirs
juxtaposed by normal
faulting against Upper
Cretaceous synrift sources
and seals.
Fig. 8: Litak, R. K., Barazangi, M., Beauchamp, W., Seber,
D., Brew, G., Sawaf, T., and Al-Youssef, W.
Mesozoic-Cenozoic evolution of the Intraplate Euphrates
fault system, Syria: Implications for regional tectonics
Journal Geological Society, London, 154, 653-666, 1997.
10. The trend of major
producing oil fields
occurs in a surface
area approximately 40
km wide. This fairway
is centered northeast
Location of oil
fields, wells, and
seismic profiles.
is centered northeast
of the Euphrates
River near Iraq and
trends northwest,
becoming more west-
northwesterly near
the Khabour River.
Fig.9: Structure and Evolution of the Petroliferous Euphrates
Graben System, Southeast Syria
Robert K. Litak, Muawia Barazangi, Graham Brew, Tarif Sawaf, Anwar
Al-Imam, and Wasif Al-Youssef4
11. Structural cross section
Corresponding to the line AA’ showed in the slide before and
recostructed by seismic interpretation constrained by several
well data. It give us general idea about of structural geology
from which we can understand the importance of secondary
faults for the formation of oil traps.
12. Fig.10: Robert K.
Litak, Barazangi.1998
Pzu = rocks of
Seismic profile of southwestern edge of Euphrates graben
system.
Pzu = rocks of
Paleozoic age
younger than
Ordovician.
13. The source
rocks are
principally the
Soukhne and
marly shales
Shiranish
formations, but it
was possible to
document other in
SOURCE ROCK
Family 2A
Family 1
Family 2B
document other in
the Silurian Tanf
formation, and
possibly within the
Carboniferous.
Family 1: Silurian Abba/Tanf Fm + Hot Shale (super-mature), good source
rock, Type II/III and Type III. Immature to early mature.
Family 2A: Upper Cretaceous Shiranish Fm, good to very good potential source
rock.
Family 2B: Upper Cretaceous Soukhne (or R'mah) Fm, mixed of Type II and
Type III, early mature.
14. SEAL
Many fields in the area with a significant productivity, are due to the
extremely numerous minor faults of the Euphrates system and the relatively
undeformed sealing lithology that exists above good reservoir rocks.
In addition to the Shiranish formation, the shaly Derro clastics have been
proven to be good seals, and several reservoir/seal pairs have been documented
in the Triassic carbonates and evaporites.
Sealing of a Carboniferous reservoir might have to rely on interbedded
shales or on being upthrown against the Upper Cretaceous carbonates.
15. The Rutba sandstone
is the most prolific
reservoir in the
graben, charged by
UK source rocks
downthrown to the
normal fault system.
Other reservoir
quality rocks have
been documented in
RESERVOIR
been documented in
the Triassic and
Carboniferous, but
more drilling is
needed to fully assess
Paleozoic lithology.
Silurian Tanf Fm is absent in the central part of the Graben. Toward SE
and NW, the Family1 is found.
Shiranish Fm generates the Family 2a, located in the central part along
the Graben axis. Maximum burial leads high thermal maturity.
Soukhne (R'mah) Fm is placed mainly in the NE and S.
16. PRODUCTION
Example of an
oil field:
Thayyem
The Thayyem oil field is an exemple of oil-producing structures,
although most of the structures are considerably thinner.
This was the first field discovered in the Euphrates play in 1985, and
remains one of the most prolific fields.
Generally, the fields are located near the deepest part of the basin. This
correlation suggests that the location of productive fields is largely
governed by the thickness and maturity of synrift source rocks.
The production from the Euphrates is around 450,000 barrels per day
(OAPEC Bulletin, 1996).
17. CONCLUSIONS
Light oil and minor gas accumulations
are found primarily in Lower
Cretaceous clastic reservoirs supported
to both large and small normal faults.
For future work in this area it’sFor future work in this area it’s
recommended to consider the Silurian
Tanf Formation source rock (contained
into Cretaceus Post Judea Sand
reservoir) caracterized by thin
interbedded shale strata rich in organic
content:
TOC>20% Hot Shale Zones
19. BIBLIOGRAPHY & SITOGRAPHY
httpviableopposition.blogspot.it201308syria-minor-oil-
player.html
Structure and Evolution of the Petroliferous Euphrates Graben
System, Southeast Syria - Robert K. Litak, Muawia Barazangi,
Graham Brew, Tarif Sawaf, Anwar Al-Imam, and Wasif Al-
Youssef - Institute for the Study of the Continents, Snee Hall,
Cornell University, Ithaca, New York, 14853 USA & Syrian
Petroleum Company, Ministry of Petroleum and Mineral
Resources, Damascus, Syria – 1998.Resources, Damascus, Syria – 1998.
Crude Oil Families in the Euphrates Graben Petroleum System -
A Ph.D thesis of Dip. Eng. Ahmad Aldahik - Berlin Institute of
Technology (TU Berlin) Helmholtz Centre Potsdam – GFZ
German Research Centre for Geosciences - 2006.
Chaimov, T. A., Barazangi, M., Al-Saad, D., Sawaf, T., and Gebran,
A. Crustal shortening in the Palmyride fold belt, Syria, and
implications for movement along the Dead Sea fault system.
Tectonics, 9, 1369-1386, 1990.
