Patent ID: 6278950
Filing Date: 2001-08-21
Classification: G01V

Abstract:
A method for correcting for amplitude variations in a set of seismic data traces where said variations are caused by a shallow subsurface layer containing attenuation anomalies and/or by seismic source and receiver inconsistencies, said method comprising the steps of:a. determining first arrival amplitudes for seismic traces having offsets greater than a predetermined value, said predetermined value being large enough to ensure that said first arrivals pass completely through said shallow layer;b. expressing said amplitude variation for said long-offset first arrivals as a mathematical function of location of said source and receivers, and of location-dependent variables, said variables determining the magnitude of said amplitude variations;c. inverting said mathematical function to solve for said variables; andd. using said variables determined from said first arrival data to correct the amplitudes of all arrivals in said set of seismic traces for said amplitude variations.