Abstract: Shear wave anisotropy of formation assumes normal correlation with fractures and fracture openings, so there exist intensive shear wave anisotropies in the fractures flled with shale or calcite. To apply this character may recognize qualitatively crack flling extent and evalu-ate carbonate reservoirs. Successful application of this method to Sangtamu horst faulting zones in Tarim basin shows that the high-angle frac-tures flled with shale or calcite appear slight anisotropy, while horizontal fracture, network fracture and conjugated fracture have few the anisotropies. In addition, this study can provide basis for seeking favorable fracture systems in Tarim's carbonate reservoirs.

Key words: acoustic logging, shear wave, anisotropy, fracture, carbonate rock, evaluation