RESERVOIR MODELING FOR MISHRIF FORMATION IN NASIRIYAH OILFIELD
Building a reservoir model is very important in the petroleum industry where it is considered the basic step for putting development plans of the field. The formation under study is Mishrif Formation in Nasiriyah oil field. To achieve a reasonable reservoir model that gives the actual performance, it is necessary to validate the model before using it for field development plans and this can be fulfilled by initialization results and history matching. This study involves building a reservoir model and validating it for Nasiriyah oilfield. Initial conditions including initial pressure, datum depth, and oil-water contact were used in the simulator. Oil-water contact is represented in the model as a surface. Fluid properties comprise of water and oil properties were employed for model construction. The validity of initialization results is achieved by a comparison between Oil Initially in Place (OIIP) values resulting from the geological model and reservoir model. The period of history matching is about ten years. The available production and pressure data were fed into the simulator. History matching is divided into three parts: production matching, pressure matching, and water cut matching. Good matching was resulted between calculated production rates by the simulator and observed production rates. Many runs of the simulator were conducted to obtain matching. Pressure matching is verified between calculated pressure by the simulator and the observed static pressure of the wells after multiplying the horizontal permeability by a factor 3.4. The field did not record water production during its production period and this was confirmed during history matching. The reservoir performance of Nasiriyah oil field indicated that the water drive is weak and the reservoir needs to support.