CT (Computed Tomography) imaging method of three-dimensional multi-well combined well land

Abstract

The invention relates to a CT (Computed Tomography) imaging method, in particular to the CT imaging method of a three-dimensional multi-well combined well land, which belongs to the technical field of engineering seismic exploration. The method comprises the steps of: based on initial arrival of a single shot of a field record, establishing a speed model when field seismic travel is picked up through the initial arrival; forward modeling and solving a ray path and a theoretical travel; then establishing an inversion equation; modifying the speed model according to time residual of travel; iterating successively and inversely calculating; and finally obtaining a high precision medium speed field. In engineering reconnaissance, generally, abnormal bodies in small scale are to be solved, and higher resolution is required. The CT imaging method of the three-dimensional multi-well combined well land is high in probe precision, low in reconnaissance cost, simple in structure, visualized in probe result, intuitionistic and clear and convenient to identify and can assist or partially replace the drilling work.

Description

technical field [0001] The invention relates to a three-dimensional CT imaging method, in particular to a three-dimensional multi-well combined well-ground CT imaging method, which belongs to the technical field of engineering seismic exploration. Background technique [0002] The original meaning of tomography is section or slice. It was first applied in the field of diagnostic medicine, and then gradually extended to technical fields such as geophysics and radio astronomy. This technology uses the artificial or natural physical field signals observed on the surface of the detection target to invert the distribution of the geometric shape and physical parameters of the object's internal structure without damaging the object. Unfavorable geological problems hidden in engineering construction, such as karst, collapsed columns, fissures, cracks, fractured and broken zones, weak interlayers, underground cavities and unknown buried objects, etc., will cause hidden dangers in pro...

AI Technical Summary

Problems solved by technology

Since the generation of refracted waves requires certain conditions, in a multi-layer medium, if the wave velocity of one layer is greater than that of all the underlying layers, the underlying strata cannot form refracted waves, so this method is limited to providing shallow layers for static correction. Velocity field, cannot be directly used for formation velocity imaging

The existing tomographic imaging technology is mainly cross-well CT imaging technology, but it has the aforementioned lateral ambiguity, which makes it impossible to make accurate imaging of abnormalities

Images