The Time-frequency Analysis Of The Application Of The Reservoir Prediction Research In North Tarim Area

Time-frequency analysis is a method that can joint the time and the frequency domain together, which can make the local characteristics of signal distinctly exhibited in such two-dimensional plane. It has a unique applied value in reservoir prediction. Tabei area, In Tarim basin, has a more complex surface condition and the reservoirs at here are often not only thin but also buried deep. Meanwhile, by the Influence of the seismic data acquisition method and equipment, the seismic data are of the lower ratio of signal-to-noise and the resolution. And the application of the traditional attribute prediction method was greatly restricted. Based on the actual geological conditions in Tabei area, the article starts researching from two aspects:the theoretical and the case study. It is emphatically on elaborating and analyzing the effect of predicting the reservoir characters by using time-frequency analysis method in the region and it is proved that the method has made a very good effect from the case studying.First of all, the basic concept of time-frequency analysis, the time and the frequency resolution problems are introduced and the paper puts emphasis on the algorithm principles of10kinds of time-frequency analysis methods, i.e., short-time Fourier transform, Wigner-Ville, wavelet transform, S transform, etc. The more important is that the paper summarizes the advantages, disadvantages and applicability of each method by analyzing the time-frequency distribution characteristics of different test signals. At last, a reference for the choosing of these methods is provided.Secondly, combining with the demand of actual geology and fully analyzing the geological condition and seismic data of Tabei area, the paper presents some rules of thumbs for deposition cycle analysis based on forward modeling and analyzing the thin sand-mud interbed model, which lay the methodological foundation for constructing the sequence stratigraphy by using seismic data. In the thin sand reservoir analyzing, the linear transitional media theory is brought in and some important points of view are acquired after forward modeling and analyzing such model, it is the spatial distribution of the thin sand reservoir that can be predicted by frequency information and that points a direction for thin sand reservoir prediction by using seismic data.At last, the results of the theoretical analysis and the forward modeling are applied to the actual seismic data acquired in Tabei area. In the first case, using the time-frequency analysis method and combining the results of forward modeling, as an emphasis part of study, seismic traces data aside7wells are used to deposition cycle analysis and finally a profile of stratigraphic framework across these7wells is established, which lays the foundation for the following fine sequence stratigraphy analysis. In the case applied in YingMaiLi distract, based on the actual demand of production and the results of thin sand modeling, the workflow of thin sand quantitative prediction is established, the core of which is time-frequency analysis. The top sand of BaXiGai formation’s prediction in YingMai A district prove that the prediction thickness coincide with subsequent drilling data and the thin sand spatial distribution is consistent with the results of geological study. The result shows that this method is deserved to be applied and popularized. This prediction workflow provides reference for identifying and quantitative predicting thin sand in comparable area.