ABSTRACT: Seismic Data Inversion Using Geologic Constraints
VEST, R. T., Vest Exploration Services, Midland, TX
Seismic data inversion has an inherent nonuniqueness problem due to the band limited nature of the seismic data. Using an interative least-squares modeling process with the conjugate gradient method, geologic constraints in the form of interval velocities can be used to vastly improve the solution of the inversion process. Sonic well logs that tie the data, as well as logs located in the vicinity of the data are used to develop constraint windows. These windows consist of bed velocities and maximum and minimum allowable interval velocities. Employing penalty functions ensures that the algorithm will honor all input constraints. The net effect of this process is the elimination of a low-frequency trend, reduced sensitivity to noise and wavelet, and an increase in the resolution of the nversion process. The final inversion, output in interval velocities, will have the same character and feel as the sonic logs in the area.
AAPG Search and Discovery Article #91018©1992 AAPG Southwest Section Meeting, Midland, Texas, April 21-24, 1992 (2009)