Egbai J.C.and Aigbogun, C.O.
In petroleum industry, well logs play a vital role in oil and gas exploration and reservoir evaluation. A well in Midwest oil and Gas Company in Imusadege Marginal Oil Field, Kwale, Nigeria was used for the research. The fundamental concepts of open wireline logging which evaluate petrophysical parameter such as porosity, water and hydrocarbon saturation and, irreducible water saturation and permeability were highlighted. The well contains eleven reservoirs, eight of which were hydrocarbon bearing while three were water bearing. These reservoirs were evaluated using gamma ray, neutron, resistivity and density logs. The evaluated well are characterized by high porosity and permeability with low clay content which is an indication for active or productive reservoir.