In this paper we obtain a linearized reflection coefficient for quasi-compr
essional waves in fracture-related equivalent media, with respect to fractu
re density and infill material. We study the conditioning number of the inv
erse problem by analysis of eigenvalues and eigenvectors of this reflection
coefficient. This is then used to investigate different acquisition geomet
ries, either with varying azimuth or with varying offset. In the reservoir
context, with fluid fill, only fracture density can be inverted using the P
-wave AVO analysis.