area ,western desert, egypt, using subsurface …
TRANSCRIPT
STRUCTURAL/ STRATIGRAPHIC IMPLICATIONS OF THE JURASSIC
CRETACEOUS~ EOCENE BASINS IN THE VICINITY OF THE QAROUN
AREA ,WESTERN DESERT, EGYPT, USING SUBSURFACE GEOLOGICAL
AND GEOPHYSICAL DATA
BY
TAMMAM MOHAMED TAMMAM
B. Sc. GEOLOGY
THESIS
PRESENTED IN PARTIAL FULLFILLMENT
/FOR THE M.Sc. DEGREE IN GEOLOGY
TO
THE FACULTY OF SCIENCE, AIN SHAMS UNIVERSITY
19 8 5
N 0 T E
The present thesis is submitted to the Faculty of
Science, Ain Shams university in partial fulfillment for the
requirements of Master of science in geoloqy.
Besides the regearch work materialized in this thesis
the author did attend l!l'ine post graduate courses for one acad-
ernie year in the following topics :
ll Field Geology
2) Geologic techniques
3) Petrophysical properties of rocks
4) Structural geoloqy
5) Geotectonic
6) Subsurface geoloqy
7 ) Electric methods
8) Sedimentation
9 l English language.
He has successfully passed the final examination of
these courses.
Prof. Dr. M.A. BASSIOUNI
17· A Head of Geology De[Jartment
Faculty of Science
Ain Shams University
A C K N D W L E D G E M E N T
The author wishes to express his thanks to Professor
Dr. M. A. Bassiouni, Head of the Geology Department, Faculty
of Science, Ain Shams Universty, for his kind help by offering
the facili,ties of the department during the preparation of
this work.
Special thanks are due to Prof. Dr. Omar H. Cherif
Professor, in the Department of Geology, Faculty of Science,
Ain Shams universty, to Dr. Ahamed s. A. Abu El-Ata lecturer
of Geophysics in the same Department and to Dr. P. S. Feather
stone Geophysist in Shell Winning N.V. Co., Cairo, for their
suggestion of the point of research, supervision of the work
and revision of the manuscript of this thesis.
Iam also very gratefull to the members of the E.G.P.C
exploration department and specially to Mr. Hedeiwy for their
support and encouragement.
- ii -
LIST OF CONTENTS
Subject
Chapter
No.
Page
No.
I. INTRODUCTION
l.
2 •
3 •
Location of the study area
History of oil exploration activity
Aims and scope of the present work
l
l
l
4
II. PREVIOUS WORK 5
III. STRATIGRAPHY 9
9
9
IV.
l.
2 •
3 .
Generalities
Main Stratisraphic units
2. 1. Basement canplex 9
2. 2. Paleozoic rocks 12
2.3. Triassic rocks 12
2.4. Jurassic rocks 12
2. 5. Cretaceous rocks 14
2.6. Paleocene,Lower and Middle Eocene 17
2. 7. Upper Eocene - Oligocene 18
2.8. Miocene 18
Correlation. 19
SUBSURFACE EVALUATION 24
24 1. Introduction
2. Isopach, facies and environments of the
Gindi Formation
3. Isopach, facies and environments of the
Khoman Formation
24
34
- iii -
Chapter
No. Subject
v.
VI.
4 •
5.
Isopach, facies and environment of the
Abu Roash Formation
4.1. Abu Roash "F" Member
4. 2. Abu Roa sh "G" Member
Isouach, facies and environments of the
Bahariya Formation
6. Isopach, facies and environments of the
Kharita Formation
7 • Geological history
GEOPHYSICAL INTERPRETATION
l.
2 .
3 .
4.
Introduction
Seismic methods
2.1. Seismic data
2.2. Velocity data
2.3. Seismic Interpretation
Gravity methods
3. l. Gravity map
3.2. Gravity interpretations
3.3. Gravity modelling
Magnetic methods
STRUCTURES AND TECTONICS
l.
2 •
Introduction
Structura 1 features
2.1. Folds
2.2. Faults
2.3. Unconformities
Page
No.
36
36
38
40
45
45
so 54
57
57
57
58
60
60
69
69
71
73
77
80
80
80
81
83
88
- i \: -
Cha12ter Pa9:e. Subject
No. No.
3 • Trend analysis 91
3. 1. Azimuth - length frequency diagram
for the Khcman faults 93
3 . 2. Azimuth - length frequency diagram
for the Bahariya faults 93
4. Tectonic elements 98
5. Tectonic regi~e 102
VII. HYDROCARBON POTENTIALITIES 104
1. Introduction 104
2. Stratigraphic sequence 104
2 .1. Source rocks 105
2. 2 • Reservoir rocks 106
2. 3 . Cap rocks 107
3. Trans£ ormation cycle 108
3. 1. Oil generation 108
3. 2. Oil migration 109
3 . 3 • Oil accumulation 111
4 . Entrapping style 112
4 .1. Structura 1 traps 112
4 . 2 • Stratigraphic traps 115
4. 3 . Combined traps 115
5. Case history of drilling results 115
VIII. SUMMARY AND CONCLUSIONS 118
IX. REFERENCES 12 cj
Fig.
No.
- v -
LIST OF FIGURES
Subject ~
No.
l. Index rna p of the study area.. . . . . . . . • . . . . . . . 2
2. Surface features............................ 3
3. Generalized stratigraphy of the eastern part 10
of the Western Desert....................... 10
4. Formation tops of the wells scattered in the
study area. . . • . • . . . . . . . . • • . . . • . . . . . . . . . . . . . . 'll
5. Stratigraphic correlation between T.57-l,GRIS-l,
KTN-1, WD 38-1 and W.RYN-1 wells............ 20
6. Stratigraphic correlation between BR 3-1, ••
BR 6-1, BR 27-1 AR-1 and AR-2 wells........ 21
7. Stratigraphic correlation between BR 3-1, .••
WD 19-3, WD 19-2, G.RIS-1 and KTN-1 wells... 23
8. Rocks units thickness....................... 25
9. Lithofacies calculation of Gindi Formation.. 26
10. Lithofacies calculation of Abu Roash "G" Member 27
11. Lithofacies calculation of Bahariya Formation 28
12. Lithofacies calculation of Kharita Formation. 29
13. Isopach map of the Gindi Formation........... 30
14. Carbonate Percentages map of the Gindi Formation 32
15. Shale Percentages map of the Gindi Formation. 33
16. Isopach map of Khoman Format ion .............. 35
17. Isopach map of Abu Roash Form a tion ..•.••..••. 37
18. Isopach map of Abu Roash "F" Member .•••.•.•.. 39
19 . Isopach map of Abu Roash "G II Member .•...••..• 41
20. Sandstone percentages map of Abu Roash "G,. Member42
21. Shale percentages map of Abu Roash "G II Member 43
- vi -
Pag . Subject
No. No.
22. Carbonate percentages map of Abu Roash "G"Member 44
23. Isopach map of Bahariya Formation •.........••... 46
24. Sandstone percentages map of Bahariya Formation. 47
25. Shale percentage map of Bahariya Formation ....•. 48
2 6. Carbonate percentages map of Bahar iya Formation. 49
27. Sandstone percentages map of Kharita Formation •. 51
28. Shale percentages map of Kharita Formation ...•.. 52
29. Carbonate percentages map of Kharita Formation •• 53
30. Seismic lines location map .. . . . . . . . . . . . . . . .. . . . . 59
31. Seismic line WHP. . . . . . . . . . .. . .. . . . . . . . .. . . . . . . .. . 62
32. Seismic line Wffi . . . . . . . . . . . . . . . . .. . . . . .... . . .. . . 64
33. Seismic line WLX . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . 65
34. Seismic line 3 BR.75 .....•••.•••..••.••...••..•. 67
35. Seismic line 3 BR 94 ..•.......•.•.••.•••...••..• 68
36. Bouguer gravity map •......•..•................•• 70
3 7 . Residual gravity rna p ......••............•....... 72
3 8 . Modelled gravity profile AR-1 to BR 2 7- l ........ 75
39 . Modelled gravity profile T.57-l to W.RYN-l. ..... 76
40. Total intensity magnetic field ........•......... 78
41. Top Khoman isochrones map ..•.................... 85
42 . Top Bahar iya isochrones rna p ...•......•........•. 87
43 . Base Khoman unconfomity surface rna p ...•.•...•.. 89
4 4. Base Gindi unconformity surface rna p •..•......•.. 90
4 5 • Base Mcqhra unconformity surface rna p ............ 92
46. AzL~uth - length- frequency table for the fault
elements cappiWj the Khoman Formation ........... 9".
- vii -
No. Subject No.
47. Azimuth- length frequency diagram for the
fault elements capping the Khoman Formation. 95
48. Azimuth - length -frequency table for the
fault elements capping the Bahariya Formation. 96
49. Azimuth- length frequency diagram for the
fault elements capping the Bahariya Formation. 97
50. Tectonic elements scattered in the study area. 101
51. Maturation map for the Abu Roash "F" Member... 110
52. Structural prospects of the study area on the
top of Bahariya Formation..................... 115
A B S T R A C T
The interpretation of subsurface geologic, geophysi
cal and geochemical data on the Qarun area in the northern
Western Desert of Egyv: enables to establish a model to clarify
the stratigraphic and tectonic peculiarities of the area and
to evaluate its hydrocarso:1 potentialities.
The used data inclurle composite logs for the 15 wells
drilled in the area, 70 seismic lines chosen according to a
grid spacing from 2 to 6 km, a Bouguer Gravity map prepared
by the geophysist,s of the Oil Companies involved in the area,
an Aeromagnetic map compiled by Robertson Research Centre and
geochemical data on organic matter content of the different
rock units penetrated by the studied wells.
Well log data enable to establish various facies and
isopach maps for the following r=k units from top to base :
Gindi Formation ( Middle Eocene to Paleocene ) , Khoman Forma
tion ( Maastrichtian - Campanian ) , Abu Roash Formation ( Se
nonian - Upper Cenananian ) , Bahariya Formation ( Lower Ceno-
rna nia n and Khar ita Formation ( .Z\1 bia n - Upper Aptian ) .
Seismic data help in the in tcrpreta tion of the stru
ctures of t•"o major reflect:or<3 : the top Khoman and top Baha-
riya surfaces. These structures are expressed in two isochrone
maps prepared by the author, these maps together with gravity
and aeranagnetic ma[ls ena!:lle to recognize the major structural
trends in the area in 'dhich a major depositional basin of NE-SW
trend is recognized : the Gindi basin . This is flanked to
the north and to the south by two structural trena& : the
Camel Pass Abu Roash and the El Faiyum highs, showing also
a NE-SW trend ( syria n arc ) . These trends are limitted by
NE-SW major faults. The major depocentre of the Eocene
falls in the middle of the Gindi basin.
Hydrocarbon potentialities evaluations give the
chance to chose two highly prospective structures on the
structural map established on the top Bahariya Formation.
These structures have been selected out of 7 structurally
fav0crabl.e locations after an analysis of the generation,
migration, rna tura tion and accumulation history of hydroc
arbons in the area.
CHAPTER I
INTRODUCTION
- l -
C H A P T E R I
INTRODUCTION
l. Location of the study area.
The Qarun area under discussion covers about 7000 km2
in the northern Western Desert of Egy,:>t, situated immediately
to the south west of Cairo (fig.l), this area is between Lat
itude 29° 12' : 30° 00 Nand longitude 30° 06' : 31° 18' E.
The surface features of the Qarun area (fig.2) can be geogra
phically divided into a large northern part of open desert,
and a smaller southern part of the Faiyum depression that in-
eludes the brackish lake Qarun. The area to the north of the
lake is marked by steep cliffs leading up to the desert plateau.
To the south, the lake is bordered by heavily cultivated land.
2. History of oil exploration activity.
Fifteen oil exploration wells in the greater Qarun area
have been drilled. Two wells were drilled in the area by Stand-
ard oil in 1946/47 on the Abu Roash uplift (AR-l and AR-2) In
the late sixties three wells were drilled by Amoco (KTN-1, G.RIE-1
and GND-1). In. the seventies both Amoco and Braspetro carried
out extensive v ibroseis seismic prog rames and drilled sev era ll
wells, as BR 3-1, RR 6-l and RR 27-1 for the later ca:npany. In
1973 Amoco ( now Gupco discovered the small WD.l9 oil field, in
which three wells were drilled (h'D.l9-l, -2 & -3), to the north
of Qarun area. In 1978, two wells were drilled by British Petro
lewn Co. (T.56-l and T.57-l). At the begining of 1984 Shell Win
ning N.V.Co. was awarded concession rights for most of the area
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