Seismic Prediction Method and Device for Formation Pressure of Sand Shale Reservoir

Abstract

The present invention provides a seismic prediction method and device for formation pressure of sand and mudstone reservoirs. The method includes: based on the Hashin-Shtrikman boundary model, according to the porosity and mud content of the target sand and mudstone reservoir in the study area, calculating Elastic modulus, micro-crack density and micro-crack closure rate factors under ultimate effective stress; based on the above-mentioned elastic modulus, micro-crack density and micro-crack closure rate factors, determine the relationship between dry rock elastic modulus and effective stress; according to the above The relationship is used to determine the effective stress coefficient of sand and mudstone that changes with depth; based on the above relationship and the effective stress coefficient, the formation pressure of the target layer to be measured in a single well is predicted; based on the above relationship and the effective stress coefficient, the elasticity obtained by the inversion is used The modulus data volume uses the formation pressure of a single well as a constraint to perform three-dimensional seismic formation pressure prediction in the study area. The above technical solution improves the accuracy of formation pressure prediction.

Description

technical field [0001] The invention relates to the technical field of formation pressure prediction in oil and natural gas exploration, in particular to a seismic prediction method and device for formation pressure of sand and mudstone reservoirs. Background technique [0002] The research on formation pressure has a history of more than 40 years. During this period, many scholars proposed various prediction methods for formation pressure based on the latest research results at that time, mainly including logging methods and seismic methods. Whether using logging method or combining seismic method, most of them use the relationship between effective pressure and velocity to predict pore pressure. The most important theoretical basis is the effective pressure principle proposed by Terzaghi in 1943. Now most velocity The conversion formulas with pore pressure are all proposed based on this principle. Hottman and Johnsom proposed the equivalent depth method to predict pore pr...

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Problems solved by technology

[0004] To sum up, the main problems of the seismic prediction method for formation pressure of sand-mudstone reservoirs in the prior art are: 1. The traditional method only uses the single parameter of seismic velocity to reflect the change of formation pressure; The mechanism is too simple

Therefore, when predicting the formation pressure of sandstone and mudstone reservoirs, the prediction accuracy is low

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