الفهرس 
Chapter one IntroductionOnly 14 pages are availabe for public view
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Abstract
The current study is attempting to define the reservoir characteristics and geological setting of the Kareem and Rudeis formations in the GH 376 oil field in the southeastern sector of the Gulf of Suez rift by employing innovative approaches for interpretation and combination between seismic reflection and well logging data. This work is based mainly on the interpretation of the available well logging and seismic data which is kindly provided by BP/GUPCO Petroleum Company after the permission of the Egyptian General Petroleum Corporation. These include four digital well logs, twenty 2D seismic sections extracted from 3D seismic dataset, mud logs for the four wells, vertical seismic profiles and a checkshot surveys. The GH 376 oil field is located within the large Shoab Ali block, where the South Gharra Concession margins the southeastern part of the Gulf of Suez rift basin, nearly between latitudes 27° 53 and 27° 59 N and longitudes 33° 41 and 33° 47 E. The goals of the present study were achieved through the interpretation of the 2D seismic sections using Petrel Schlumberger modeling software. Seismic structure maps were executed, in addition to the geologic modeling. Extensive seismic interpretation is carried out to map and model the subsurface geology of the study area. To achieve the goals of the present study, the following steps were applied to the available data: 1) seismic well tie, 2) picking horizons and interpreting faults, 3) mapping of picked horizons to construct horizon’s depth map, 4) constructing the subsurface geological model, and 5) the interpreting the different maps and cross-sections. Three horizons were selected for interpretation: The first shallow horizon is the top South Gharib Formation. This horizon is easily recognized on the seismic sections as the top of a dome shape. The second one is the top Kareem Formation; where it is not easily visible on seismic sections and was hard to be picked due to the faults affect. The third deeper horizon in the section is the basement rocks. The operation of creating fault polygons was carried out in order to map the important reservoir horizons and understand their structure impact. This process is achieved after building the faults sticks, 3D Fault–Plain model. The five detected faults are modeled in 3D sense. The fault modeling is followed by the horizon mapping that has been achieved through editing the picked horizons and gridding the results. The generated maps represent the seismic structure maps. All interpreted horizons and faults are stratigraphically and structurally modeled based on their geological relationship. Well logging records were applied to evaluate petrophysical characteristics of the upper Rudeis, lower Rudeis, and Kareem formations. These horizons were selected as they are the main reservoirs in the study area. The interpreted data have been illustrated in the form of cross-plot and tables. The detailed petrophysical characteristics showed variable volume of shale, porosity and water saturation, hydrocarbon reserves, and net pay thickness. The latter ranges from 0.5 to 14.5 ft for the Kareem Formation, 1.5 to 51 ft for the upper Rudeis, and 11.5 to 83 ft for the lower Rudeis Formation. The volume of shale for Kareem reservoir ranges from 10% at well GH 376-A3 to 25% in the well GH 376-A1, for the upper Rudeis Formation, it lies between 14% in well GH 376-A1 to 23% in the well GH 376-A4, and for the lower Rudeis reservoir, it ranges from 11% in well GH 376-A3 up to 23% in the well GH 376-A4. The porosity of the Kareem Formation ranges from 12% in well GH 376-A2 to 21% in the well GH 376-A3, and 12% in well GH 376-A3 up to 23% in well GH 376-A4 for the upper Rudeis Formation, and 18% in well GH 376-A2 and 20% in wells GH 376-A1 and GH 376-A4 for the lower Rudeis Formation. The water saturation for the Kareem Formation ranges from 53% in GH 376-A2 well up to 100% in GH 376-A1 well, for the upper Rudeis Formation, it ranges from 38% in well GH 376-A4 to 81% in well GH 376-A2, and for the lower Rudeis Formation, it lies between 28% in well GH 376-A3 and 38% in well GH 376-A4. The present study indicated that the Kareem Formation is suffered from compartmentalization process as a result of complex series of normal faults along with fault related to anticlinal structure. The anticlinal structure has NNW axis trend. The fault planes are generally directed toward the NW-SE direction. The resulted anticlinal structure is mainly of Miocene age and is related to the time of the syn-rift phase in the Gulf of Suez. The normal faults form horsts, grabens and half grabens. Indeed, the Miocene evaporites are considered as the ultimate vertical seal for the hydrocarbon plays. Unfortunately, no Nubia reservoirs have been investigated in the current study. This absence is believed to be due to the paleogeography highs located in the study area that obstructed the deposition of this deeper horizon. It is concluded from literature and previous works that the Nubia sands are stratigraphically pinch-outs against these paleohighs. Based on these results, it is recommended to drill a new well to test the Kareem and Rudeis reservoirs in the small horst. This new well is endorsed to be parallel to the GH 376-A3 well. It is recommended to study other possible reservoirs such as Nukhul and Nubia clastic reservoirs.