Abstract

Application of 3D Reservoir Modeling on Zao 21 Oil Block of Zilaitun Oil Field

Peprah Agyare Godwill and Jackson Waburoko

Reservoir modeling is an effective technique that assists in reservoir management as decisions concerning development and depletion of hydrocarbon reserves must be taken considering the uncertainties of the formation involved. The paper focuses on the use of Petrel Software to construct a 3D-dimensional reservoir model that characterizes and evaluate Zao 21 block reservoir located in Dagang Oil field zilaitun area in Hebei Province of China which has an oil bearing area of 0.9 km2. The approach is based on integration of data from seismic, well logs of 41 wells obtained from geology, geophysics, petrophysics, to characterize and provide an accurate description of the internal architecture and visualization of reservoir heterogeneity. These data are used to build the lithofacies, porosity, permeability and oil saturation model which are the parameters that describe the reservoir and provide information on effective evaluation of the need to develop the potential of the remaining oil in the reservoir. The lithological facies architecture is simulated using Sequential Indicator Simulation to guide the distribution of petro-physical properties of the reservoir since they are intimately related. In addition, the petro-physical parameters are simulated using Sequential Gaussian Simulation. The reservoir structural model shows system of different oriented faults which divided the model into two segments, the major and minor segments. Statistical analysis of the Porosity model, permeability model for Zao 21 block showed that porosity is mainly concentrated between 12.5% to 22.5% with an average porosity of 15.5%; and permeability mainly between 40 mD~ 110 mD, with a mean permeability of 81 mD; overall good reservoir properties. The estimation of these values was used to quantify the geological reserve of Zao 21 reservoir block oil deposit. This study has shown the effectiveness of 3D reservoir modeling technology as a tool for adequate understanding of the spatial distribution of petro-physical properties and in addition framework for future performance and production behavior of Zao 21 block reservoir. The reservoir model reveals that the reservoir properties of the north-eastern part of the oil field are very promising and wells should be drilled to investigate and exploit the oil.