Characterization and description method of sand bodies in ultra-deep coal reservoirs

Abstract

The invention discloses a method for characterizing and describing the sand body of an ultra-deep coal upper reservoir, which includes the following steps: firstly, through different models forward modeling, the waveform characteristics of the erosion-type pinch-out point and the characteristics of the coal seam are analyzed, and the sand body boundary of the actual data is obtained. Provide the basis for determination and stripping of coal seams; identify the pinch-out line of the sand body by using the optimal point of the bottom trough attribute of the overlying strata; use the multi-channel dynamic matching tracking method under the control of the horizon to strip the strong shielding of the coal seam and highlight the weak signal of the reservoir ; On the basis of the strong shielding and stripping of coal seams, the frequency spectrum components of the main information of the reservoir are reconstructed in the time-frequency domain by using the high time-frequency resolution of GST, and the processed data can predict sand bodies more accurately; finally According to the three-dimensional wave impedance data volume obtained by GR pseudoacoustic wave impedance inversion, the reservoir prediction results are obtained through comprehensive analysis. The method of the invention can effectively describe the pinch-out line of the sand body, accurately predict the range of the sand body of the ultra-deep reservoir, and is of great help in improving the accuracy of seismic reservoir prediction.

Description

technical field [0001] The invention belongs to the field of seismic data interpretation, and in particular relates to a method for depicting and describing the sand body of an ultra-deep coal upper reservoir. Background technique [0002] Affected by multiple sets of coal seam interbeds, the seismic reflection energy of the target layer is covered by the coal seam; the target layer of seismic data is denuded, and the block contains multiple sets of sand groups, and different sand groups are superimposed in the vertical direction, increasing The difficulty of delineating the boundary of sand bodies is difficult; ultra-deep reservoirs are generally low-porosity and low-permeability tight reservoirs, and the reservoirs have strong lateral heterogeneity. big uncertainty problem. Therefore, how to choose a reasonable reservoir description method is very important for finely describing coal-bearing ultra-deep reservoirs. Contents of the invention [0003] The purpose of the p...

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