Imaging method of seismic wave fields between inclined wells

Abstract

The invention relates to an imaging method of seismic wave fields between inclined wells, comprising the following steps of: 1) scattering and gridding space areas between two adjacent inclined wells; taking each of the grid nodes as a secondary source point; 2) calculating the time TSD needed for transmitting a seismic focus S to each of the grid nodes according to a first-motion wave travel-time nonlinear interpolation ray-tracking method; 3) taking the actually recorded wave field as source by a receiving point; extrapolating the reverse time of each of the grid nodes to the TSD moment by using a speed-stress-first order differential equitation staggered gridding finite difference method, wherein the wave field at the moment is the image of the grid point; and 4) when the wave field is transmitted to a medium border, as the border wave impedance difference is large, using a completely matched layer to absorb the border, namely a PML layer; absorbing and attenuating the wave field so that the wave field cannot return to the medium and form interference.

Description

technical field [0001] The invention relates to the field of energy exploration and development, in particular to an imaging method for an interwell seismic wave field of an offshore inclined well. Background technique [0002] At present, the cross-well seismic imaging method has developed from the ray theory to the elastic wave theory, and from the vertical well to the deviated well imaging method. The crosswell seismic wave field is complex and rich, including both upgoing and downgoing reflection wave fields, and it is difficult to separate the wave fields. Especially in the case of offshore inclined wells, the difficulty of separation is even more obvious. Most existing conventional crosswell seismic stacking imaging methods based on ray theory have poor fidelity and amplitude preservation of imaging results. Conventional reflection wave stacking imaging methods, such as VSP-CDP stacking imaging, require the input to be a single wave field, which often leads to unsati...

AI Technical Summary

Problems solved by technology

Most existing conventional crosswell seismic stacking imaging methods based on ray theory have poor fidelity and amplitude preservation of imaging results

Conventional reflected wave stacking imaging methods, such as VSP-CDP stacking imaging, require the input to be a single wave field, which often results in unsatisfactory imaging results due to unclean wave field separation

For oil layers that have been developed for many years, the inter-well reservoir changes relatively large, and the anisotropy problem is more prominent, and the conventional wave field imaging method always has certain problems

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