Petrophysical Evaluation and Pressure Analysis of the Cretaceous Alam EL-Bueib Sand Reservoirs, Jade Field, North Western Desert, Egypt

Abstract

The present study deals with integration between petrophysical evaluation and reservoir pressure analysis toevaluate the hydrocarbon bearing sand zones of Jade field in north Western Desert, Egypt. Eight wells scattered in Jadefield are analyzed and studied for determining the different petrophysical parameters of the Lower Cretaceous Alam ELBueibreservoirs. This study reveals the presence of three hydrocarbon-bearing sand zones (Alam EL-Bueib-3D, Alam ELBueib-3E and Alam EL-Bueib-3G) with good hydrocarbon potential encountered at different depth levels in the Alam ELBueibFormation. The well log analysis of the Alam EL-Bueib reservoirs including; data editing, data correction, anddetermination of lithology and porosity using different types of cross plots such as density-neutron and M-N cross plots.The density-neutron cross plots show that the Alam EL-Bueib reservoirs are mainly sandstones with some calcareouscement. The bulk density ranges from 2.3 to 2.6 g/cc. The effective porosities are 11.5, 14.2 and 11.05 %, and the shalevolumes are 10.6, 5 and 5.9 % in the Alam EL-Bueib-3D, 3E and 3G, respectively, implying good reservoir quality.Petrophysical parameters of the Alam EL-Bueib reservoirs are illustrated on iso-parametric maps to delineate the mosteffective sand zones. The iso-parametric maps of the Alam EL-Bueib reservoirs such as net pay, effective porosity andgross sand show an increase in the central southern and northern parts of the study area especially in Alam EL-Bueib-3Dand 3G units, while in Alam EL-Bueib 3E unit shows an increase in the central southern part only. The analysis ofreservoir pressure data is concerned mainly to locate the different fluid contacts and determine the pressure gradients of oiland gas-bearing zones. It gives necessary knowledge about the driving mechanisms that control the behavior of fluidswithin reservoirs.