The Adaptive Well Log Data Interpretation in Geological Modeling

Abstract

AbstractWidespread application of 3D geological modeling in oil and gas field development practices resulted in substantiation of the transition from the traditional concept of "absolute pore space?? to the concept of "effective pore space??. This could be achieved with the geophysical and well logging data interpretation algorithms and procedures focused on the determination of reservoirs dynamic characteristics with high vertical resolution and based on principles of adaptability and petrophysical invariance.The adaptive log data interpretation technology provides analytical relations between log interpretative parameters and reservoir rocks properties in the generalized form. Proposed interpretative algorithms are implemented in the geological modeling software package and combined with standard geological modeling procedures to develop the three-dimensional distribution of reservoir properties.Adaptive petrophysical models make possible the quantitative estimation of effective porosity and effective/phase/relative permeability. Formation parameters, which characterize the content of bound water in the framework and cement, maximum total porosity and effective porosity. Dependencies between effective porosity and effective permeability are estimated according to outcomes of petrophysical modeling. Effective porosity is calculated with the interpretation of standard log data. The distribution of reservoir properties in three-dimensional space is carried out with geostatistical simulation techniques. Application of effective porosity for prediction of relative permeability and capillary pressures with log data was realized as an important task for field development design.The test of the proposed technology is conducted on a large number of wells worldwide (Western and Eastern Siberia, Caspian region, Middle East, Alaska, etc.). Formations consist of clastic fine-grained sandstones with cement and framework complex mineral composition. Application of proposed technology in geological modeling software packages represents an innovative direction of geological information technologies. It does not require any special capital expenditure with a significant economy of forces and operational time.