Velocity field construction method and device

Abstract

Embodiments of the invention provide a velocity field construction method and device. The method comprises the following steps of: calculating velocity values at junctions of multiple well points andmultiple geological interfaces; carrying out interpolation calculation on the velocity value at the junction of each geological interface so as to obtain a first velocity value of the geological interface; obtaining a second velocity value of each geological interface on the basis of a reference velocity field obtained via pre-stack depth migration; constructing an error velocity field on the basis of the first velocity values and the second velocity values; and correcting a reference velocity field by using the error velocity field so as to obtain a target velocity field for time-depth conversion. By utilizing the method, data related to depth domains with correct well points and reasonable geological laws can be obtained in complicated rift basins.

Description

technical field

[0001] The present application relates to the technical field of petroleum geological exploration, in particular to a method and device for constructing a velocity field. Background technique

[0002] Depth-domain structural map is the most important basis to guide the layout of exploration wells, but it is generally difficult to obtain directly through measurement. Seismic data is used for structural interpretation to obtain two-way travel time data in the time domain, which is more of a feedback to the measured velocity. In this way, velocity becomes the most direct bridge to convert time-domain data into depth-domain data. How to use effective logging data and time-domain seismic data to establish an accurate velocity model is particularly important. An accurate velocity model has a decisive influence on the later exploration efficiency.

[0003] At present, there are six velocity modeling methods, namely Dix formula velocity modeling, offset homing velo...

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