U. S. PATENT ABSTRACTS The following is a list of Abstracts of issued United States Patents during the review period.
6,836,448 INVENTORS: Robertsson, Johan Olof Anders; Curtis, Andrew Robertsson; ASSIGNEE: Schlumberger Technology Corporation; ISSUE DATE: December 28, 2004
System and method for seismic wavefield separation 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 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.