f Anisotropy Effects in a Three-Component 3D VSP

Fractured rocks with a regional trend of faults constitute several hydrocarbon reservoirs. Often, their cracks cannot be observed directly by seismic waves: then, an equivalent medium with an azimuthal anisotropy is the only reliable way for estimating their presence. The crack directions decide the fluid movements in the reservoir: thus, the detection of the anisotropy type allows optimising the depletion wells for oil and gas production.