Formation evaluation of Abu Madi reservoir in Baltim gas field, Nile Delta, using well logs, core analysis and pressure data

Abstract

Baltim Eastern and Northern gas fields in the offshore Nile Delta have very high gas condensate accumulations. Therefore, the present research evaluates Abu Madi and Qawasim Formations and defines the petrophysical parameters for them using various data from five wells composed of wireline logs (gamma-ray, density, neutron, sonic, resistivity), core data, pressure data, and cross-plots. In the current study, the formations of the main reservoirs were evaluated qualitatively and quantitatively based on the petrophysical analysis to assess the production potential. Based on the lithological identification, the two main reservoirs (Abu Madi and Qawasim Formations) are composed of sandstone, calcareous shale, and siltstone. The main petrophysical parameters (Shale volume, effective porosity, net thickness, and fluid saturations) were mapped to track the areal petrophysical variations in the field. The results of the petrophysical analysis reveal that the main reservoirs are promising for the hydrocarbon potential with effective porosity of 18%, low shale content with an average value of about 21%, higher gas saturation of average value of nearly 58%, net reservoir thickness ranges from 25.5 to 131.5 m, net pay thickness (effective thickness) ranges from 6 to 61 m. Also, the conventional core analysis affirms that the main reservoirs are of good effective porosity with high horizontal and vertical permeability values. There is a good match between the well-log results and the pressure data with the production data (DST “perforation tests”). Baltim East (BE3) well has the most desired petrophysical characteristics in the Baltim East gas field, while, the Baltim North-1 (BN1) well showed the most favorable petrophysical parameters in the Baltim North gas field. Different fluid contacts (gas water contact GWC) were detected by integrating all reservoir pressures. The integration of different data in our present work (well logs, core measurements, and pressure data) could reduce the drilling risks and help to determine the best locations for future exploration and development, which is considered a big challenge in the petroleum industry.