Migration velocity analysis methods

摘要

A method of performing migration velocity analysis may include: obtaining seismic data and an initial velocity model; determining reflection points; deriving a wavepath backprojection operator based on the initial velocity model and the reflection points by constructing wavepaths from each reflection point of the reflection points; and performing a traveltime inversion using the wavepath backprojection operator. The initial velocity model may be updated based on the traveltime inversion. Determining reflection points may be automated by calculating reflection points based on results from a depth migration algorithm performed on the initial velocity model. Selection of residual moveout values may be automated by selecting based on a dip field for each prestack gather obtained from a depth migration algorithm performed on the initial velocity model. Residual traveltimes may be calculated using the selected residual moveout values. The residual traveltimes may be used in the traveltime inversion.