A method and device for predicting fracture development

Abstract

The invention provides a fracture developing predicting method and device, and relates to the technical field of petroleum geophysical prospecting. According to the invention, a longitudinal wave velocity azimuthal anisotropy feature based on pre-stack wide azimuth seismic data is used to predict a fracture. The method comprises the steps that according to pre-set azimuth and offset range, sub azimuth and sub offset part superposition is carried out on pre-stack seismic gather data; wavelet needed by the inversion of the azimuth superposition data body of each part is determined; a low frequency model of longitudinal wave velocity, shear wave velocity and density needed by seismic inversion is determined; pre-stack elasticity parameter data corresponding to a number of partial azimuth superposition data bodies are determined; according to a least squares method, ellipse fitting is carried out on the longitudinal wave velocity inversion data and the shear wave velocity inversion data of each partial azimuth superposition data body to determine the elliptic equation parameters of the ellipse; the long axis or minor axis orientation of the ellipse is determined to characterize the fracture development direction; and the ratio of the long axis to the minor axis of the ellipse is determined to characterize the fracture density.

Description

technical field [0001] The invention relates to the technical field of petroleum geophysical exploration, in particular to a method and device for predicting fracture development based on the anisotropic characteristics of longitudinal wave velocity of pre-stack wide azimuth data. Background technique [0002] Fractures are an important type of reservoir space in carbonate rocks, which are discontinuous surfaces without obvious displacement formed in rocks by tectonic deformation or physical diagenesis. The formation of cracks depends on the type of stress on the rock and the nature of the rock, its abundance and distribution and stress, rock type (brittle or ductile), structural state, depth (overlying pressure), lithology, rock thickness, pores Degree, phase, age and other factors. In the field of petroleum geophysical exploration, for carbonate reservoirs, fractures are not only the main pathways for oil and gas migration, but also have great significance for improving r...

AI Technical Summary

Problems solved by technology

[0005] Embodiments of the present invention provide a method and device for predicting fracture development to solve the problems existing in the prior art that it is difficult to accurately predict the direction of fracture development in thin reservoirs in fracture prediction and the inability to overcome the non-uniqueness of direct parameter inversion

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