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AssigneeSchlumberger Technology Corporation
InventorsJohan Olof Anders Robertsson, Andrew Curtis
Estimating the term…
A system and method of creating a filter for use with locally dense seismic data is disclosed. The method includes obtaining survey geometry characteristics from a locally dense seismic survey. A filter is designed which uses spatial derivatives of the wavefield of order between (1) and the maximum order of spatial derivatives of the wavefield that can be estimated within a group. The filter can be designed so as to separate up/down going components, p/s components, or both up/down and p/s components. Partial derivatives in space and time of the wavefield can be calculated, using, for example, a taylor series expansion as an approximation. The seismic data is filtered by combining estimated near surface material properties, the seismic data, and the calculated partial derivatives.
A method of creating a filter for use with locally dense seismic data comprising the steps of:
A method according to any of the preceding claims wherein each of the densely spaced receivers in the group are spaced apart such that statics in the portion of the wavefield of interest are substantially constant.
A method according to any of the preceding claims wherein each of the densely spaced receivers in the group are spaced apart by about 2 meters or less.
A method according to any of the preceding claims wherein each of the densely spaced receivers in the group are spaced apart by a distance of about one fifth the shortest wavelength of interest or less.
A method according to any of the preceding claims wherein the locally dense seismic survey comprises generating elastic or acoustic waves, and the receivers in a group span less than about the smallest wavelength of said elastic or acoustic waves.
A method according to any of the preceding claims wherein the near surface velocity is essentially isotropic.
A method according to any of the preceding claims wherein the near surface velocity is anisotropic.
Dependencies are inferred from the claim text.