Within the geophysical profession, the word static is associated with several diverse topics:
seismic reflection and refraction methods, in which static corrections are normally applied to surface topography and near-surface layers;
magnetotelluric method (MT), in which static shifts are used to adjust the data for resistivity inhomogeneities or topography; and
spontaneous potential (SP) logs, in which the static SP is a measure of the voltage between a thick, clean, water sand and the shale line.
Figures & Tables
Static corrections for seismic reflection surveys
“This reference manual is designed to enable more geophysicists to appreciate static corrections, especially their limitations, their relationship with near-surface geology, and their impact on the quality of final interpreted sections. The book is addressed to those involved in data acquisition (datum static corrections), data processing (datum static and residual static corrections), and interpretation (the impact that unresolved static corrections, especially the long-wavelength or low-spatial-frequency component, have on interpretation of the final section). Simple explanations of the underlying principles are included in an attempt to remove some of the mystique of static corrections. The principles involved are illustrated with simple models, supplemented with many data examples. This book details differences in approaches that must be considered among 2D, 3D, and crooked-line recordings as well as between P-wave and S-wave surveys. Static corrections are shown to be a simplified yet practical approach to modeling the effects of the near surface where a more correct wavefield or raypath-modeled method might not be undertaken efficiently. Chapters cover near-surface topography and geology; computation of datum static corrections; uphole surveys; refraction surveys; static corrections limitations and effect on seismic data processes; residual static corrections; and interpretation aspects. An extensive index and a large list of references are included.”