Process for creating image gathers

摘要

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 (θ) or a general domain parameter (α) 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.

主权项

1. A process comprising:
obtaining seismic data by deploying a seismic energy source and seismic receivers, actuating the source, and detecting seismic energy reflected from a plurality of subsurface positions resulting therefrom at the receivers; forming a plurality of traces by digitally sampling the seismic energy detected at the receivers and indexing the seismic energy with respect to time; sorting the traces to form a plurality of shot gathers; 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; converting the images to reflector dip angle domain; computing a reflection angle (θ) at each subsurface position, wherein the reflection angle at at least one subsurface position corresponding to an image point {right arrow over (x)} defines a local reflection angle (θ({right arrow over (x)})) computed using the following formula:
θ({right arrow over (x)})=cos−1(I1/I0); mapping the images according to the corresponding reflection angle to form common image gathers; transforming the images to space domain; applying amplitude correction to common image gathers; and storing the images and common image gathers on non-transitory computer-readable media.