Using shear waves to predict lateral variability in vertical fracture intensity

Abstract

During the last five years, the use of shear-wave splitting in geophysical exploration has made the transition from research project to very promising field technique. The measurement of the azimuth of the fast shear-wave and analysis of the S-wave splitting (or birefringence) are now commonplace. Furthermore, a very timely practical application is suggested by the recent proposal that reflectivity on post-rotation S1 and S2 data sets should indicate lateral variation of anisotropy. This could be of great value because the determination of lateral variation in fracture intensity in a vertically fractured sedimentary layer is necessary to insure high efficiency in a horizontal drilling program designed to drain the fractures.