A small-scale geological body velocity modeling method and system constrained by geological horizons

Abstract

The invention discloses a small-scale geological body velocity modeling method and system constrained by geological horizons, including: step 1: tracking the target layer of the small-scale abnormal body, and determining the target layer of the target layer; step 2: calculating the target layer The local depth difference between the expected horizon and the expected horizon; Step 3: Construct the small-scale anomaly body tomographic objective function according to the local depth difference; Step 4: Based on the small-scale anomaly body tomographic objective function, perform multi-scale inversion to obtain the small-scale Abnormal body velocity update amount. The present invention introduces the local depth difference between the target layer and the expected layer of the small-scale velocity anomaly body into the tomographic inversion, effectively improving the spatial resolution of the velocity modeling of the small-scale anomaly body, thereby improving the modeling accuracy, At the same time, the multi-scale inversion technology realizes the gradual approximation of small-scale velocity anomalies from low wavenumber to high wavenumber, which improves the stability and rationality of velocity modeling of small-scale anomalies.

Description

technical field [0001] The invention belongs to the field of seismic imaging and inversion, and in particular relates to a small-scale geological body velocity modeling method and system constrained by geological horizons. Background technique [0002] The goal of seismic imaging is to use the forward and reverse propagation of seismic waves to locate, identify and describe underground structures, and provide intuitive and reliable basis for the exploration of underground oil and gas reservoirs. However, the precision of seismic wave imaging depends on the accurate velocity model of subsurface medium. With the deepening of exploration and development, the targets faced by seismic imaging are becoming more and more complex, such as igneous rock intrusions, strike-slip faults, ancient buried hills and other special geological bodies due to their complex and changeable lithology, high and steep structure, weak seismic response, etc. In terms of characteristics, the conventiona...

AI Technical Summary

Problems solved by technology

With the deepening of exploration and development, the targets faced by seismic imaging are becoming more and more complex, such as igneous rock intrusions, strike-slip faults, ancient buried hills and other special geological bodies due to their complex and changeable lithology, high and steep structure, weak seismic response, etc. In terms of characteristics, the conventional velocity modeling technology reflects a certain degree of incompatibility, which seriously restricts the process of seismic imaging towards refinement.

In particular, the velocity anomalies of igneous rocks are small in scale, the lithology changes drastically, and the inversion accuracy of conventional velocity modeling techniques is insufficient.

Images