A Geologic Model for Carbonate Reservoirs in Kenneyak Oilfield

Carboniferous reservoirs in Kenneyak oilfield, located at the eastern edge of the Pre- Caspian basin, are carbonate reservoirs with fractures and cavities as the main pore types. The reservoirs can be divided into 3 types according to pore types: fracture- pore- cavity reservoir, pore - cavity reservoir and micro - fissure reservoir. As carbonate reservoirs have well developed fractures and cavities, it is difficult to build geologic models for reservoirs of fracture and cavity types. A frame for building geologic models is defined through description of the sedimentary distribution features of reservoirs; the distribution patterns of micro - fissures and cavities in different porosity ranges are determined based on analysis of core and logging data; and the fractures and cavities are quantitatively characterized by using density porosity and matrix porosity data. The principles of geostatistics are used in inter -well reservoir prediction and geological modeling to ensure the prediction accuracy of different reservoir types. Conditional modeling methods are used to build porosity models. A set of technical methods are summarized in this paper to build distribution models for carbonate reservoirs by using geostatistics theory and density porosity, drill rate, analytical core porosity and permeability data.