Petrophysical Studies on Upper Bahariya and Abu Roash “G” ‎Reservoirs Using Well Logs in Karama Field, North Western ‎Desert, Egypt

Abstract

The present study deals with petrophysical analysis to evaluate the hydrocarbon-bearing reservoirs in the Karama field, East Abu Gharadig basin Northern part of the Western Desert. Some wells which spread around the Karama field are being investigated and studied to determine the different petrophysical characteristics of the Upper Cretaceous Upper Bahariya and Abu Roash "G" reservoirs. This analysis indicates the presence of significant hydrocarbon potential in the Upper Bahariya and Abu Roash "G" reservoirs at different depth intervals. The well log analysis involves data editing, data verification, and lithology, porosity assessment using a density-neutron cross plot. The density-neutron cross plots indicate that the Upper Bahariya reservoir is mainly sandstones with some calcareous cement. Abu Roash "G" reservoir is mostly composed of limestone with some sandstone, shale, and siltstone lithology. The shale volumes are 10-19 % and 11-18 % in the Abu Roash "G" and Upper Bahariya reservoirs respectively, and the effective porosities are 14-20 % at the Abu Roash "G" while reaching 12-16 % at the Upper Bahariya reservoir, implying good reservoirs quality. Petrophysical parameters of the Abu Roash "G" and Upper Bahariya reservoirs are illustrated on iso-parametric maps to delineate the most effective locations with good hydrocarbon potentialities. The iso-parametric maps such as net pay, effective porosity, and hydrocarbons saturation show an increase in the southern parts of the study area especially in Abu Roash "G" reservoir, while the Upper Bahariya reservoir shows an increase in the north-western parts. This analysis gives necessary knowledge about the distribution of fluids within reservoirs.

Reservoir Quality, Lithotype Assessment, and Geochemical Source Rock Analysis: Insights from Well Logs and Pyrolysis Data, Karama Field, North-Western Desert, Egypt

“…The reservoir's formation water resistivity value (Rw) was measured within the range of 0.0123 to 0.0489 ohm\m. Subsequently, the prescribed threshold values for the Abu El Gharadig Basin were implemented, encompassing an effective porosity of 9%, a saturation level of 65%, and a shale content of up to 35% [7,9,27].…”

“…However, the Late Cretaceous Abu Roash Formation of sandstone, limestone, and shale overlies the Bahariya Formation. The Late Cretaceous Khoman Chalk Formation unconformably overlies the Abu Roash Formation and underlies the Paleocene/Eocene Appollonia Limestone Formation [4,7,9,10,27].…”

“…The Karama oil field is a component of the basin's southeast side. Since several oil and gas discoveries have been reported within its thick marine Cretaceous sequence, this basin is currently thought to be the most promising basin [4,7,9,15,[26][27][28]. About 185 kilometers from 6th of October city, the area under investigation is situated between latitudes 29 °32 ′ 25.45 ″ N and 29 °34 ′ 36.98 ″ N and longitudes 29 °29 ′ 37.78 ″ E and 29 °32 ′ 04.42 ″ E (Figure 1(a)).…”