Physical constraints on c_(13) and Thomsen parameter delta for VTI rocks

摘要

From observation of static mechanic measurement of VTI rock or rock-like VTI materials, we reasoned that one of the three primary Poisson's ratios of real VTI rocks should always be bigger than the other two and they should be generally positive. From these relations we derived strict physical constraints on c_(13) and Thomsen parameter δ. Some of the published data from lab velocity anisotropy measurement are lying outside of the constraints, we analyzed that it is primarily caused by the big uncertainty associated with the diagonal phase velocity measurement. These physical constraints will be useful for our understanding of Thomsen parameter 8 and predicting 8 from non-diagonal measurement.