Patent ID: 7069200

Claim:
A method for determining reflection travel times of seismic events picked on 3D records of seismic data corresponding to signals picked up by seismic receivers distributed along an acquisition line in response to an emission in a subsoil of waves from source points, the seismic data having been previously converted to cylindrical wave data and interpreted, comprising: a) defining a slowness vector ({right arrow over (p)}) whose component (p x ) in a direction parallel to the acquisition line defines a slope of the cylindrical wave; b) for a seismic receiver situated at abscissa (X R ) on the acquisition line, seeking an abscissa (ξ) of at least one source point on the acquisition line such that rays starting from the seismic receiver at abscissa (X R ) and reflecting on a picked event emerges at the said at least one source point, with the slowness vector ({right arrow over (p)}) whose component in a direction of the acquisition line is (−p x ); c) determining a travel time (t e (X R )) for the said at least one source point by adding to a value of travel time along one of the said rays a time equal to a product of the slope of the cylindrical wave by the abscissa of the said at least one source point; d) repeating steps b) and c) for all positions of the seismic receivers for which a demigration result is wanted; and e) repeating steps a) to d) for all the values taken by parameter (p x ) for which an event has been picked in corresponding migrated data.