Reservoir characterization utilizing the well logging analysis of Abu Madi Formation, Nile Delta, Egypt

Abstract

The petrophysical evaluation of the Late Miocene Abu Madi Formation were accomplished based on the open hole logs of eighteen wells in Abu Madi–El Qar'a gas fields, onshore Nile Delta, Egypt. The lithological contents of this rock unit were analyzed using the cross plots of petrophysical parameters including shale volume, porosity and hydrocarbon saturation. The neutron /density cross-plots, M-N and RHOMAA–DTMAA and litho-saturation cross plots of the studied wells show that the main lithology of the lower part of Abu Madi Formation is calcareous sandstones with shale intercalations in most of the studied wells while its lithology is mainly shale with sand intercalations in wells AM-13, AM-21 and AM-7. The lithology of the upper part of Abu Madi Formation in most wells is composed mainly of shale while its lithology in AM-13, AM-21 and AM-7 wells is composed of sandstone with shale intercalations. The thorium-potassium cross plots indicate that, Abu Madi Formation was deposited mostly in fluvial to shallow marine environments according to the presence of mica and illite in the southern area and montmorillonite at the northern area as dominant clay minerals. Contour maps of several petrophysical parameters such as effective thickness, average shale volume, average porosity and hydrocarbon saturation showed that both lower and upper parts of Abu Madi Formation in the study area have promising reservoirs characteristics; in which the prospective area for gas accumulation located toward the central part.