Abstract: The process of obtaining seismic data includes deploying a seismic energy source and seismic receivers, actuating the source, and detecting seismic energy resulting therefrom at the receivers. The process further includes digitally sampling seismic energy detected at the receivers indexed with respect to time to form a plurality of traces and sorting the traces to form a plurality of shot gathers. In addition, the process includes applying a depth migration technique to the shot gathers to generate two images according to the cross-correlation imaging condition (I0) and the gradient-based imaging condition (I1) for each shot gather. A reflection angle (?) or a general domain parameter (?) is computed at each subsurface position and the images are mapped according to the corresponding reflection angle or the general domain parameter to form common image gathers. Amplitude correction is applied to common image gathers and the images and common image gathers are stored on non-transitory computer-readable media.

Abstract: The process of obtaining seismic data includes deploying a seismic energy source and seismic receivers, actuating the source, and detecting seismic energy resulting therefrom at the receivers. The process further includes digitally sampling seismic energy detected at the receivers indexed with respect to time to form a plurality of traces and sorting the traces to form a plurality of shot gathers. In addition, the process includes applying a depth migration technique to the shot gathers to generate two images according to the cross-correlation imaging condition (I0) and the gradient-based imaging condition (I1) for each shot gather. A reflection angle (?) or a general domain parameter (?) is computed at each subsurface position and the images are mapped according to the corresponding reflection angle or the general domain parameter to form common image gathers. Amplitude correction is applied to common image gathers and the images and common image gathers are stored on non-transitory computer-readable media.

Abstract: The process of obtaining seismic data includes deploying a seismic energy source and seismic receivers, actuating the source, and detecting seismic energy resulting therefrom at the receivers. The process further includes digitally sampling seismic energy detected at the receivers indexed with respect to time to form a plurality of traces and sorting the traces to form a plurality of shot gathers. In addition, the process includes applying a depth migration technique to the shot gathers to generate two images according to the cross-correlation imaging condition (I0) and the gradient-based imaging condition (I1) for each shot gather. A reflection angle (?) or a general domain parameter (?) is computed at each subsurface position and the images are mapped according to the corresponding reflection angle or the general domain parameter to form common image gathers. Amplitude correction is applied to common image gathers and the images and common image gathers are stored on non-transitory computer-readable media.

Abstract: A prestack migration method allowing imaging of an underground zone, for a given velocity model of arbitrary complexity. The method allows obtaining elementary migrated images associated with the values assumed by a parameter and the sum of the images obtained for the different values of the parameter (post-migration stacking), in the depth domain as well as in the time domain. This migration is independent of the volume of the results calculated and of the number of seismic traces recorded. Volume images are obtained by taking account of all the seismic traces. Azimuth movout correction is applied to the received data to compensate for drift.

Abstract: A prestack migration method allowing imaging of an underground zone, for a given velocity model of arbitrary complexity. The method allows obtaining elementary migrated images associated with the values assumed by a parameter and the sum of the images obtained for the different values of the parameter (post-migration stacking), in the depth domain as well as in the time domain. This migration is independent of the volume of the results calculated and of the number of seismic traces recorded. Volume images are obtained by taking account of all the seismic traces. Azimuth movout correction is applied to the received data to compensate for drift.

Abstract: A prestack migration method allowing imaging of an underground zone, for a given velocity model of arbitrary complexity. By means of conventional wave propagation and retropropagation modelling tools, the method allows to obtain elementary migrated images associated with the values assumed by a parameter and the sum of the images obtained for the different values of the parameter (post-migration stacking), in the depth domain as well as in the time domain. This migration is obtained at an attractive price (calculation cost) because it is independent of the volume of the results calculated and of the number of seismic traces recorded. Only the volume of the zone in which the waves are propagated, the complexity of the events to be imaged and the desired accuracy have an effect on the calculation cost. Volume images are thus obtained by taking account of all the seismic traces.

Abstract: The object of the method according to the invention is to synthesize zero-offset seismic data from data acquired within the scope of three-dimensional (or possibly two-dimensional) multiple-offset seismic reflection prospecting operations in a subsurface environment. It mainly comprises selection of a distribution model of the velocities in the environment, seismic data prestack migration (stacking of the multiple-offset seismic events is achieved in the depth domain), and synthesis of zero-offset seismic data in the time domain by applying to the results obtained with this depth domain stacking a known modelling technique, for example that referred to as explosive reflector technique.