Abstract
The author carried out reservoir characterization and flow simulation studies as a member of the multidisciplinary study team formed to optimize the production scheme of Iwafune-oki oil field. This paper presents the geostatistical modeling of submarine fan deposits in the field. Stratigraphic framework for each horizon boundaries and fault surfaces were modeled by integrating well-marker data and depth-converted seismic horizons. Three-dimensional distributions of shale volume contents (Vsh) and effective porosity were modeled using various geostatistical techniques. The modeling procedure was validated by comparing the geostatistical facies model with a deterministic geological facies model. All available information, including production data were integrated into the model, which clearly answered many questions that could not be explained with the deterministic one and changed the team's view on the field. Findings from this study led management's decision to apply gas injection for oil recovery enhancement. The field's oil production has been dramatically improved by the proposed gas injection.
