A method and system for predicting reservoir fractures based on vsp

Abstract

The present application provides a method and system for predicting reservoir fractures based on VSP. The method includes: establishing an observation system and setting parameters of the observation system; obtaining VSP data corresponding to each excitation point through the observation system; The components are horizontally rotated and oriented according to preset conditions to obtain an orientation angle sequence; each orientation angle in the orientation angle sequence is subtracted from the corresponding excitation point azimuth angle to obtain a polarization angle sequence; the obtained polarization angle The sequence is averaged, and each polarization angle is subtracted from the average value to obtain a residual angle sequence; and the residual angle sequence is converted into a seismic rose diagram. The VSP-based reservoir fracture prediction method and system provided in the embodiments of the present application visually display the orientation and strength of fractures in the form of a seismic rose diagram, which improves the prediction accuracy of reservoir fractures.

Description

technical field [0001] This application relates to the field of petroleum exploration, in particular to a method and system for predicting reservoir fractures based on VSP. Background technique [0002] With the development and utilization of oil and gas resources, the reserves of conventional porous oil and gas reservoirs are decreasing day by day, and the difficulty of development is gradually increasing. The direction of oil and gas exploration has gradually shifted from conventional oil and gas reservoirs to special oil and gas reservoirs. Fractured oil and gas reservoirs in special oil and gas reservoirs are widely distributed and have gone through various geological historical periods, occupying an important position in exploration and development. The difficulty in the exploration and development of fractured oil and gas reservoirs lies in how to predict the orientation and development degree of fractures in the reservoir rock mass. At present, methods for predicting...

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Problems solved by technology

[0005] The above-mentioned Walkway-VSP is based on the time-difference analysis of forward ray tracing theory, which is affected by the accuracy of the model and the accumulation effect of the overlying strata. At the same time, the excitation points are relatively rare, which is not conducive to statistical calculations, so the accuracy of predicting reservoir fractures is not high; the above-mentioned Walkaround-VSP It is suitable for roughly predicting the development of formation fractures near wells. Due to many factors such as static correction, time-distance curve picking accuracy, and the cumulative effect of overlying formation velocity, the accuracy of predicting formation fractures is not high.

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