Petrophysical characterization of the tertiary oil reservoir, Northern Iraq

This paper introduces a comprehensive petrophysical study to re-evaluate reservoir quality of ‘Main Limestone’ reservoir units for one Iraqi oil field using modern software and techniques. In this study, we discussed many subjects, such as petrophysical effects on hydrocarbon accumulation, hydrocarbon mobility, and hydrocarbon productivity of the field. The determining reservoir properties include formation porosity, hydrocarbon, and water saturation, as well as net/gross thickness ratio, which is determined depending on wire-line logs data. For reservoir description, full sets of well log data such as gamma-ray, resistivity, neutron log, form three wells were interpreted and analyzed. The performed analysis includes many subjects such as lithology description, reservoir identification, reservoir fluid type identification, well correlation, reservoir porosity, saturation (for hydrocarbon and water) determination. Petrophysical properties parameter of ‘Main Limestone’ reservoir rocks exposed that unit 'B' has better properties compared with other units. The most overall porosity type was primary porosity through the entire formations and units. Water saturation and shale volume estimations indicated the water saturation significantly affected by an increase in the shale quantity if shale volume exceeds 10%.