Abstract The Nubian Sandstone Formation is a significant hydrocarbon reservoir in the Concession 59D, Eastern Sirt Basin, Libya. This formation is underlain uncomfortably by granitic basement and/or by the Hercynian unconformity and overlain uncomfortably by Pre-Upper Cretaceous followed by an Early Upper Cretaceous Transition beds. The Nubian formation is a thick sequence comprises mainly of sandstone, siltstone and shale.The Nubian Formation in this area has been subdivided into three stratigraphic members; namely Lower Sandstone, Middle Shale and Upper Sandstone (main reservoir well be focus of this study).The Upper Sandstone is the upper most subdivision of the Nubian Sandstone sequence consists mainly of white, grey to brown sandstones, ranging from fine to medium, locally coarse grained, moderately cemented with straight to concavo convex or slightly sutured grain contacts. This reservoir is a complex of fluvial sands deposited in Braided and Meandering streams.The reservoir fluids are very rich retrograde condensate gas and waxy oil with pressure at slightly above the saturation pressure. Most of this hydrocarbon in this reservoir has been sourced from the Nubian Middle Shale Member, but the Upper Cretaceous shale and Evaporates belonging to the Transition beds sequence have a significant potential source. The trapping mechanism in the field is a combined structural and stratigraphic trap for the Nubian Sandstone with the southern closure against the tight Nubian facies and basement of the Gialo High. Reservoir properties across the North Gialo Study Area vary in terms of porosity, permeability fluid saturation. These variations are indicated through the porosity, permeability and saturation maps and charts based on well log analysis and lab core sample measurements. These properties are discussed in the reservoir characterization part of this thesis.
عواطف عبد الله بودربالة (2012)

تعتبر التربة الطينية من انواع التربة الصعبة ذات المشاكل الهندسية نتيجة لظروف تكوينها والتأسيس عليها يكون صعباً بسبب حدوث الحركة النسبية في المنشأ نتيجة الانتفاخ او الهبوط.ويعتبرالطين من المكونات الرئيسية للسبخة ولهذا اجريت الدراسة الجيوتقنية لتربة السبخة بالمنطقة من سرت الى البريقة حيث تصل عدد العينات الى 300 عينة على طولالمنطقة . والدراسة الجيوتقنية مهمة عند اقامة مشاريع انشاء البنية التحتية مثل المنشآت ,والسكة الحديدية , والطرق , وانابيب الماء والغاز . وفي هذا البحث تم اجراء عدة تحاليل جيوتقنية لهذه التربة لما لديها من مشاكل ولانها من التربة الصعبة.وشملت الدراسة الحقلية التجارب اختبار الاختراق القياسي واختبار التحميل الموقعي واختبار مروحة القص . ومنها صنفت بانها مكونة من تربة رملية مختلطة بنسب متفاوتة من الطين والطمي والاختبارات المعملية مثل اختبارات اللدونة والتحليل المنخلي واختبار الضغط الغير محصور.ومن هذه اوضحت ان التربة منخفضة اللدونة ووجد ان تماسك التربة يزداد بزيادة عدد الطرقات في التربة ومنها يقل هبوط التربة . ونجد ان التربة الطينية متماسكة لان دليل اللدونة PI = 7 – 17 .لقد بينت نتائج المقارنة ان المناطق التي تحتاج لتحسين تميزت بكثافة نسبية ضعيفة ومقاومة قص منخفضة بالاضافة لقيم هبوط عالية آخداً في الاعتبار وجود المياه في السبخة .بينت علاقات المقارنة بين هبوط التربة في كل من الاختراق القياسي والتحميل الموقعي شكل (6.6) ان الهبوط في التربة السبخية في مواقع الدراسة يختلف من نقطة لاخرى ويتراوح من 20 الى 100 مم ومن هذا نجد ان التربة التي تحتاج لعمليات تحسين هي المواقع التي يتعدى الهبوط فيها 25 مم .وبينت العلاقة بين العمق والكثافة النسبية في شكل (7.6) ان الكثافة النسبية ضعيفة من عمق 0 الى 6 متر . Abstract The clay soil is considered one of the difficult types and have engineering problems due to its composition. The foundation upon the clay soil may face some troubles because of relative movement as a result of heave or settlement of the substrate .The clay is one of the main components of the sabkha, therefore the present study was carried out on the geotechnical properties of the sabkha soil along the area from Sirte to Brega. Up to three hundreds samples were taken from the studied area .The geotechnical study is very important for the construction of Infra structure projects , such as huge buildings , railway roads , asphaltic roads and pipes of water and gas. In this research, several geotechnical tests were undertaken for the sabkha soil, because of it is hard and have some problems.The field study included the standard penetration test, load testing and test site fan of the storytelling. According to the different tests, the soil was classified as composed of sandy soil mixed with varying conte- nts of clay and silt .The laboratory tests such as tests for plasticity, sieve analysis and unconfined compression test were performed. These showed that low soil plasticity and found that the cohesion of the soil increases with the number of blows in the soil, associated with settlement of the soil. We find that the clay soil is cohsion because it has coherent index plasticity PI = 7 - 17. The results of the comparison showed that the areas that need to improvement are characterized by relatively low density and low values of resistance to shear , in addition high values of settlement, with taking into consideration into account the presence of water in the sabkha. The relationships between the comparative settlement of soil in each of the standard penetration site and download the form fig. (6.6) that settlement of the sabkha soil in the studied sites varies from one point to another, ranging from 20 to 100 mm .Therefore we find that the soil which needs to improvement processes is located in the sites that have settlement which exceeds than 25 mm. The relationship between the depth and relative density fig. (7.6) showed that the relative density is weak from a depth of 0 to 6 meters.
سالمة ابراهيم محمد (2010)

Abstract This study covers the Fields producting from the Gialo Formation a reservoir which is composed of Limestone and Dolomitic-Limestone and consists mainly of highly altered Nummulitic Packstone. This study was achieved through three parts of study including a petrographic study, petrophysical study of reservoir properties from core analysis and borehole logs. The general geological framework was obtained from petrographical study of thirty six thin sections, 129 representative core plug data and logs from 5 different wells are utilized to better understanding the petrophysical framework of the formation. The plots correlating petrophsical parameters and the frequency histograms suggested the presence of distinctive reservoir trends. These discriminations were also represented in Winland porosity- permeability cross plots resulted in clusters for different port-size that are responsible for different flow characteristics. Linear and multiple regression were used for the study of each unit. The permeability models were constructed and their reliabilies were compared by the regression coefficients for predictions in un-cored well. The combination of all data revealed the worst ranked reservoir quality corresponded to moldic and intergranular pore types, which occurred mainly in the Bioclastic Wackstone facies. The highest ranked reservoir quality corresponded to intragranular and intergranular which occurred mainly in the Nummulitic Packstone Facies.
وردة الشوشان (2010)