Abstract: Reflected-transmitted non-converted and converted seismic waves as used for seismic imaging which is not limited by the angle of inclination of the seismic interfaces. These wave signals are recorded at the surface and are later used to obtain seismic imaging of geological discontinuities and the physical properties of the medium. Known duplex waves are used with transmitted waves for obtaining seismic images from much wider angles, ranging from horizontal to vertical. Two types of migration procedures are used: the first one being based on migration of transmitted compressional and converted duplex waves, and the second one being based on the joint migration of two interrelated fields, such as interferometric principles; for example, the first field of primary waves corresponding to the one time reflected monotypic compressional (non-converted) type of waves and a second wavefield corresponding to secondary waves of more complex origin, such as reflected waves and converted waves.

Abstract: Reflected-transmitted non-converted and converted seismic waves as used for seismic imaging which is not limited by the angle of inclination of the seismic interfaces. These wave signals are recorded at the surface and are later used to obtain seismic imaging of geological discontinuities and the physical properties of the medium. Known duplex waves are used with transmitted waves for obtaining seismic images from much wider angles, ranging from horizontal to vertical. Two types of migration procedures are used: the first one being based on migration of transmitted compressional and converted duplex waves, and the second one being based on the joint migration of two interrelated fields, such as interferometric principles; for example, the first field of primary waves corresponding to the one time reflected monotypic compressional (non-converted) type of waves and a second wavefield corresponding to secondary waves of more complex origin, such as reflected waves and converted waves.

Abstract: A Method for Interpreting Seismic Data Using Duplex Waves is described. Whereas substantially horizontal boundaries are readily identified using conventional processing methods based on primary reflections, it has been difficult or impossible to use such methods for locating substantially vertical events or boundaries. The method of the present invention uses secondary reflections to locate substantially vertical events by gathering common source or receiver traces for processing. Wave fields of these gathers are continued downward to the level of the base boundary, then at each discrete depth level, a seismic image of sub-vertical events is formed. The downward-continued gathers correspond to the travel time of the wave from when it left the source or the receiver point, was reflected from the base boundary, and arrived to the corresponding point of the discrete level of wave-field continuation.