A composite log suite that comprised of gamma ray, resistivity, density and neutron logs of six wells (Agate, Diamond, Apatite, Calcite, Copper and Jasper) were employed to evaluate the petrophysical properties of the reservoirs of interest in XY field Golf of Mexico. This was done to evaluate the trend and values of the petrophysical properties of the reservoirs in the field, while the objective was to delineate and predict the reservoir system quality and performance. Correlation was carried out across the 6 wells using gamma ray, resistivity, neutron and density logs. The distribution and occurrence of these lithostratigraphic units appeared to reflect the influence of basin morphology and sea level variation. Tops and bases of 6 reservoirs of interest were mapped. Shale Volumes (Vsh) were computed using gamma ray log; the reservoir versus non-reservoir was delineated by applying cut-off of 80% computed volume of shale with the guide of spontaneous potential (SP) and deep resistivity logs for wells Agate and Diamond. Computed Vsh was used for effective porosity to discount for the effects of clay bound water. The average

Keywords : Basin Morphology, Gulf of Mexico, Permeability, Porosity, Reservoir Sand, Shale Volume, Water Saturation, Well Logs.