f Crosswell reflection migration by a constrained Kirchhoff integral method

Migrated crosswell reflections can produce high resolution images of the earth structure. To achieve good imaging several problems must be overcome. First, crosswell reflections can be obscured by a mixture of interfering wave types, such as direct waves, S-waves, converted waves, multiples and tube waves from both wells. Secondly, any crosswell reflection survey has only limited aperture. Thirdly the ray coverage is very uneven in terms of both the number of visiting rays and the ray incident angles. Rays with large incident angles will stretch the source wavelet, and cause loss of resolution in the migrated section.