Reservoir characterization, in relation to the petrophysical modeling of Baharyia formation, Razzak field, northern western desert, Egypt

Abstract

The present work aims to investigate the reservoir characterizations of the Lower Cenomanian Baharyia Formation by creating isoparametic maps to calculate the petrophysical parameters and detect the favorable parts for oil accumulations using the available well logging data. Baharyia Formation is one of the main hydrocarbon sandstone reservoirs in the northern Western Desert of Egypt. About 90% of the Western Desert field produces form Baharyia sandstone Formation. This has been achieved through the analyses of the conventional wireline logs and petrophysical modeling. The Baharyia Formation comprises a complex of depositional lithofacies such as interbedded siltstone, shale, sandstones and pebbly sandstones. Petrophysical modeling of the Baharyia Formation was performed, based on the interpretation of complete wireline logs from five wells in Razzak oil field, north Western desert, Egypt. Petrophysical analysis accomplished, such as: shale volume, total and effective porosities, water saturation and hydrocarbon saturation, were deduced and utilized in the petrophysical subdivision of the Baharyia Formation. Relations between theses petrophysical parameters are established to define the implications of such parameters on the Baharyia Formation. Iso-parametric and litho-saturation crossplots are used to delineate variations in petrophysical parameters across the area. The obtained petrophysical results reveal that, the Baharyia Formation have a good reservoir quality, with high effective porosity values exceeding 18%,volume of shale about 30% and low water saturation values of 25%. The rock genetic types of the Baharyia Formation deduced form the log curve shapes proved that the Baharyia Formation was deposited from fluvial to marine environments passing through the tidal flood plain conditions. However, the lithology of the Baharyia Formation composed of sandstone, siltstone, shale and minor limestone inter-beds.