Clastic Reservoir Modeling Approach To Study

With the proceeding of oil production, Oilfields of the world have come into high-water cut stage. But for old oilfields, there are still large amounts of remaining oil stored in place. How to characterize the distribution of remaining oil and enhance oil recovery is the main aim of exploration and exploitation. Reservoir geologic modeling, not only the main content of reservoir description, but also the basis of developing reservoir, plays an important role in the overall exploration and exploitation.This dissertation takes Gangxi oil field as an example, on the basis of drilling cores, well logging, seismic data, the sedimentary micro-facies of reservoir, the spread of sandbodies have been studied and reservoir geology data base has been established. By using high-resolution sequence stratigraphy theory, high-resolution seismic data processing technology, wide-band constrained seismic data inversion method, reservoir geostatistics and reservoir stochastic simulation technology, 3D reservoir model is established. The main results are as follows:(l)Based on core analysis and well logging data, by using high-resolution sequence stratigraphy, the reservoir in Gangxi oilfield has been separated, and the genetic of stratigraphy sequence has been explained. The layering can be taken as the elements of reservoir stochastic geologic modeling,(2)In order to enhance the resolution of seismic data, wavelet transformation method has been used. Firstly, the seismic signal has been decomposed at different frequency. Then the signals which have different frequency are processed with the application of spectrum discrimination method.(3)The method of seismic impedance inversion restrained by well log is introduced in this dissertation. On the basis of layering interpreted by seismic processing, constrained by the single well, by methods of interpolation and extrapolation, it generate the initial impedance model, and modify the initial model continuously until the modified model approach to real seismic signal.(4)With the combination of Bayes Indicator Conditional Simulation method and Sequential Gaussin Simulation method, the distribution of reservoir heterogeneity has been predicted. (5)Multiple-point geostatistics is applied to simulate the distribution of lithfacies. The Simulation result has shown that using multiple-point geostatistics can reproduce heterogeneity and variability of sandbodies.Modeling method advanced in this dissertation has been verified by practical data of Gangxi oilfield.and the results can describe the characteristic of reservoir spatial distribution accurately. Therefore, the results of this paper not only have great theoretical significance, but also have important role for guiding exploration and exploitation in oilfields.