Method Research And Application Of Seismic Reservoir Prediction

The main task of seismic reservoir prediction has been subtle lithologic hydrocarbon reservoir, being transformed from simple structural hydrocarbon reservoir, some new methods and techniques’application depend on the improvement of seismic resolution. At present, an important factor being found to effect seismic resolution is the formational absorption attenuation, leads to a big decline of seismic-wave high frequency information, makes seismic resolution decrease. This paper bases on a systematical analysis of seismic-wave absorption attenuation mechanism, shows that many factors can affect seismic-wave absorption attenuation, an overall analysis to be combined with practical materials is needed for right decision. In order to solve the problem fully and find the countermeasure of seismic resolution improvement, we should clearly recognize the reason to absorption attenuation. This paper presents the relationship of formation hydrocarbon bearing and absorption attenuation factor being drew from practical materials, extracts absorption coefficient system in part Wennan area on the basis of the frequency comparison program, results to a more profound knowledge of absorption attenuation properties in the area after general research and analysis.In recent years, the research of time-frequency analysis theory has penetrated every field. The field of geophysical science pays more attention to time-frequency analysis, and obtains fine results. Fourier transform, Wigner-Ville distribution and Wavelet transform and so on are important techniques for signal processing. Different means has different pros and cons, the applicable time-frequency analysis way should be chosen in different condition. After comparison of different means, it is the Wavelet transform that can do a better job in seismic signal portraying, make precise time-frequency analysis. Also, Wavelet transform can be more elasticity and adaptability based on wavelet function diversion. Based on the excellent character of part research, this paper chooses Wavelet transform method for time-frequency analysis in target area, and obtains fine results.The relationship analysis of formation rock physical property parameters is the foundation of whole reservoir prediction, involves speed, density and porosity, gamma ray value, wave impedance, permeability, saturation and other kinds of formation parameter. There is a definite relation between the parameters. To make their relationship clearly and find the pattern between them will play a foundation role in the reservoir prediction identification and research.According to the data, this paper makes the rock property analysis, develops multiple statistical and intersectional analysis between lithology, property, hydrocarbon and geophysical characteristic parameters, mainly based on the materials of logging and reservoir dynamic in the central plains and the target research area of well-19containing precise information, then gets the rock property relationship in Wennan area, provides the basis for the later reservoir prediction.Seismic attenuation is an irreversible process of seismic-wave energy partially being transforming into thermo during its propagation in the layer. The information of attenuation and absorption has intimate relation to rock lithology and formation hydrocarbon, and the formation absorption coefficient has outstanding effect to frequency information. Seismic-wave attenuation information is a significant property being picked up from P-wave reflection materials, as considered far more sensitive to formation lithology and hydrocarbon than other parameters, such as velocity, density. In current seismic exploration, with the development of directly hydrocarbon detection and exploration, Seismic attenuation gets more and more attention. To detect reliable magnitude of attenuation is an important theme of both practical and theoretical in oil exploration. This paper mainly combines practical seismic materials to pick up absorption coefficient using comparison of frequency spectrum in target area, analysis shows the absorption coefficient of gas-bearing horizon is higher than peripheral layer, then to combine with materials of geology and logging, a preferable oil prediction can be obtained after multidisciplinary analysis. In the application of actual exploration, the method is proved to be good in recognizing gas reservoir, can give a good guidance for later development.