3D geological modeling of dual porosity carbonate reservoirs: A case from the Kenkiyak pre-salt oilfield, Kazakhstan

Abstract

The 3D geological model of dual porosity reservoirs in the Kenkiyak pre-salt oilfield is built step by step based on the detailed core observation, employing core data, log data, geological data, and seismic data. Firstly, the structural model is built. Then the sedimentary facies model is built on the basis of analyzing seismic facies and electro-facies, and the models of reservoir matrix properties controlled by the sedimentary facies are built based on structure analysis and methods optimization. Secondly, the fracture distribution model is established by applying the results of the seismic property analysis and the core fracture description. Thirdly, the three-dimensional integrated geological model of the dual porosity reservoirs is set up by combining the matrix property models with the fracture distribution model and applying the filtration theory between matrix and fractures. The set of methods finally provides a fracture distribution model, a fracture equivalent permeability model, and a dual porosity equivalent permeability model, which can be directly provided to reservoir engineers for numerical simulation. Key words: dual porosity, 3D geo-modeling, fracture, equivalent permeability, Kenkiyak Oilfield