This paper is concerned with geological and petrophysical characteristics of the Abu Roash “D" resesvoir in the G.P.T. Field, Abu Sennan area, using primarily the well log data. The subsurface geological studies were accomplished through the study of the lithostratigraphy, the regional structural deformations and the tectonic implications in the field area in addition to petrographic analysis. Computer-assisted log analyses were used to evaluate petrophysical parameters such as the shale content, effective porosity, water saturation, hydrocarbon saturation, flushed zone saturation and true resistivity. Litho-saturation crossplots of the studied wells, and isoparametric maps of the weighted petrophysical parameters of the investigated rock unit (shale content, effective porosity, water saturation and net pay thickness of hydrocarbon saturation) have been constructed to illustrate the spatial variation of petrophysical parameters and to show their relationships with the geologic setting of the study area. Based on the obtained results, the oil potential and the development of the Abu Roash “D" Member in the G.P.T. Field should be taken into consideration. The reservoir rock analysis revealed that Abu Roash “D" Member may be considered as a good reservoir and the better chances for more hydrocarbon reserves in the field area may exist in the central parts that have high effective porosity, low shale content and low water saturation.