Modeling And Removal of Back-scattered Noise From Rough Topography In Land Seismic Data Available to Purchase

Land seismic data is commonly contaminated by coherent and high amplitude back-scattered noise generated from roughness in the surface topography; these events generally obscure the information of most interest from deeper layers. In Colombian foothill areas with rough topography and high lateral velocity variation, this noise has been difficult to attenuate. Conventional methods aimed at this purpose usually yield unsatisfactory results. We present a strategy based in prediction and subtraction of the unwanted waves. Assuming knowledge of the source wavelet and the shallow velocity model we use a finite-element solution of the acoustic wave equation to model the back-scattered noise; this modeled response is then subtracted from the data, resulting in a noticeable attenuation of the noise in the records, in both synthetic and field cases.