Reservoir fracture predicting method and system based on VSP

Abstract

The invention provides a reservoir fracture predicting method and system based on VSP. The method includes the steps that an observation system is built and parameters of the observation system are set; VSP data corresponding to each excitation point are obtained through the observation system; horizontal rotating orientation is carried out on a first component and a second component corresponding to each excitation point on each depth layer according to preset conditions and an orient angle sequence is obtained; a corresponding excitation point azimuth angle is subtracted with each orient angle in the orient angle sequence to obtain a polarization angle sequence; the average value of the obtained polarization angle sequence is resolved, the average value is subtracted from each polarization angle, and a residual angle sequence is obtained; the residual angle sequence is converted into an earthquake rose diagram. According to the reservoir fracture predicting method and system based on VSP, by means of the earthquake rose diagram, the position and intensity of a fracture are visually displayed, and reservoir fracture predicting precision is improved.

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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