الفهرس 
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Abstract
The present thesis deals with the structural interpretation of twenty nine seismic
reflection sections beside the formation evaluation using ten well logs in the Upper
Cretaceous rocks of the Abu Gharadig Field of the Abu Gharadig Basin, Western Desert,
Egypt. It aims to evaluate the reservoir characterization and general sequence stratigraphic
configuration of the Bahariya and Abu Roash formations penetrated in the mentioned area.
Interpretation of twenty nine 2D seismic sections and TWT structural contour maps
for six reflectors (Bahariya Formation, Abu Roash ”G” Member, Abu Roash ”E” Member,
Abu Roash ”C” Member, Khoman Formation and Apollonia ”D” Member), of the Late
Cretaceous to Paleogene succession has detected four different fault sets that affected the
Upper Cretaceous rocks of the study area. These are oriented NW-SE, WNW-ESE, NE-SW
and ENE-WSW.
Most of the faults affecting the Abu Gharadig Field die out in the Late Maastrichtian
Khoman Formation. A few faults, however, affect the lower Khoman Formation and die out in
the Apollonia Formation. This indicates that the major tectonic movements which gave the
Abu Gharadig Field its present shape took place near the end of the Late Cretaceous. The
production in Abu Gharadig Field in most wells is controlled mainly by the ENE tectonics of
the Late Cretaceous age.
Most of the faults affecting the Abu Gharadig Field die out in the Late Maastrichtian
Khoman Formation. A few faults, however, affect the lower Khoman Formation and die out in
the Apollonia Formation. This indicates that the major tectonic movements which gave the
Abu Gharadig Field its present shape took place near the end of the Late Cretaceous. The
production in Abu Gharadig Field in most wells is controlled mainly by the ENE tectonics of
the Late Cretaceous age.
The petrophysical parameters (porosity and net pay thickness) and facies distribution
of Bahariya and Abu Roash formations increase toward the NW and NE directions and were
controlled by faults attaining the same direction.
Interpretation of the seismic sections, the two-way time structural contour maps and
the petrophysical characteristics of the Abu Gharadig Field, lead to the prediction of two
prospect areas (closures A and B, lying in the NW and NE of the study area) for drilling new
wells. The selection of these two prospect areas is based on a high structural closure, located
at the intersections between NW and NE trending fault systems, with good petrophysical characteristics.
The well log analysis of the Upper Cretaceous (Cenomanian–Santonian) succession in
seven well logs in the studied area allowed its classification into ten major third-order
depositional sequences, separated by eleven major depositional sequence boundaries. This
succession is subdivided into twenty one systems tracts. These systems tracts include: 1
systems tract of Albian age; 10 systems tracts of Cenomanian age, 5 systems tracts of
Turonian age and 5 systems tracts of Coniacian-Santonian age
The history of base-level changes and associated shifts in depositional trends has been
reconstructed for thirty consecutive time steps during the Albian to Santonian intervals,
showing repeated cycles of transgression and highstand normal regressions, whereas the
lowstand normal regression was only represented in depositional sequence 1 and 9 (SQ1 and
SQ9) due to fluvial and channels incision during this time.
Based on number and volume of pay reservoir intervals, it is clear that the
hydrocarbon potentiality (as related to the different systems tract in the studied seven wells in
the Abu Gharadig Field) decreases from the transgressive to the lowstand and finally
highstand systems tracts, respectively. On the other hand, as the pay reservoir intervals in the
lowstand systems tract are thicker than the pay intervals in the other systems tracts, it is
possible then that the hydrocarbon production in the Abu Gharadig Field is greater from the
lowstand systems tracts than the transgressive ones, and this, in turn, is greater than the
highstand systems tracts. This order accords with the world-wide arrangement of the explored
fields and productivity.
Thus, it is recommended that any future developmental plans for gas and oil
production from the Abu Roash and Bahariya formations in the Abu Gharadig Field would be
directed to the NW and NE areas. Also, it is recommended that any future exploration and
developmental plans in Abu Gharadig Field would be directed first to localities of lowstand
systems tracts, then next to transgressive systems tracts, then finally to highstand syste tracts.