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Title: Geological and geophysical evaluation of Tertiary sedimentary succession at the hinge-zone area between Sirte Basin and Cyrenaica Platform, NE Libya
Author: El-Shari, Saad M.
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 2000
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This research project aims to recognise and understand the relationship between lithology, stratigraphy and structural setting across the hinge-zone between Sirte Basin and Cyrenaica Platform to the northeast. This is the first time that the Tertiary sedimentary rocks in the north-eastern Sirte Basin have been the subject of detailed structural and stratigraphic investigation. The systematic approach through geological and geophysical interpretation using seismic reflection data, aided by synthetic well data, is the most suitable way to attain the research objectives, especially since the study area has only a few real wells. This study integrates structural interpretation of seismic data, velocity analysis, depth conversion, seismic sequence stratigraphy, well correlation and porosity and subsidence analysis. Interpretation of the structural features seen on the seismic sections and their mapping with relation to geological time has defined the structural history in the east Sirte Basin. All the depositional sequences dip toward the southwest (basin direction) and faults are the most prominent structure in the area. Most faults are normal trending NW-SE with downthrow towards the basin. Velocity analysis has been carried out as a useful tool for local stratigraphic interpretation and lithology evaluation and also for the conversion of two-way time to depth to the top of each sequence. The difference between seismic derived velocity, check-shot and sonic log velocities has been examined to establish the effect this difference might make in the determination of the true velocity distribution. Average velocity and interval velocity maps have been constructed for each sequence. Time to depth conversions for complex models including laterally variable velocities and reflector structure have been done. This depth-conversion method results in depth maps with exact well ties and geologically reasonable depth estimates away from wells. By applying seismic sequence stratigraphic techniques in the area, depositional environments are interpreted using the resultant facies analysis and the characterisation of reflections.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available