Abstract for Geophysical Prospecting, 45, 165-184, 1997.
Azimuthal variation in AVO response for fractured gas sands
by
Colin M. Sayers and James E. Rickett
Schlumberger Cambridge Research, Madingley Rd, Cambridge CB3 0EL, UK
ABSTRACT
Natural fractures in reservoirs play an important role in determining
fluid flow during production, and hence the density and orientation of
fractures is of great interest. In the presence of aligned vertical
fractures, the reflection amplitude at finite offset varies with
azimuth. The effect of natural fractures on the azimuthal AVO response
from a gas-sandstone reservoir. A simple expression
for the difference in P-wave reflection coefficient from the top of the
reservoir parallel and perpendicular to the strike of the fractures is
obtained in terms of the normal and tangential compliances Z