Method for analyzing pre-stack time migration and speed based on common scatter point channel set

Abstract

The invention provides a method for analyzing pre-stack time migration and speed based on a common scatter point channel set. The method comprises the following steps of: mapping a pre-stack two-dimensional or three-dimensional data according to an equivalent migration distance principle to obtain the common scatter point channel set; performing NMO (Normal Move-Out) correction on the common scatter point channel set to obtain a root-mean-square speed; stacking the corrected channel sets according to scatter points to obtain a pre-stack time migration result; generating the common scatter point channel set for a plurality of scatter points by utilizing an initial speed (such as, conventional stacking speed); obtaining a root-mean-square speed field at larger control point intervals through interactive speed analysis on the basis of the channel sets; regenerating a new common scatter point channel set at a new speed, and then performing interactive speed analysis; and realizing the pre-stack time migration and speed analysis based on the common scatter point channel set by iterating through the two steps and obtaining a high-precision root-mean-square speed field on the basis of obtaining a high-precision pre-stack time migration result.

Description

technical field [0001] The invention belongs to the field of seismic data processing, and is a pre-stack time-domain migration imaging and velocity analysis method applicable to complex surface and complex underground structure conditions. Background technique [0002] After the emergence of the common center point (CMP-Common Middle Point) gather processing method, CMP gather motion correction (NMO-Normal Move-out), horizontal stacking, and post-stack migration constitute the routine seismic migration processing process (Zhang Kai , 2008). The conventional velocity analysis method based on CMP gathers is an important part of this processing flow, which provides the velocity field for the whole processing flow. Conventional processing methods assume that the underground structure is a horizontally layered medium, and under this assumption, the time-distance curve corresponding to the CMP gather is hyperbolic. At this time, the superposition velocity can be accurately deter...

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Problems solved by technology

[0010] The purpose of the present invention is to address the increasing difficulty in dealing with seismic exploration target reservoirs in most old oil areas in my country. Conventional processing methods have been unable to meet actual production requirements. Underground complex steep structures, extremely deep target reflectors and complex reservoirs are currently A pre-stack time migration and velocity analysis method based on common scattering point gathers is provided to solve the main seismic geological problems faced by seismic exploration in my country's old oil areas

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