Joint PP- and PSV-wave amplitudes versus offset and azimuth inversion for fracture compliances in horizontal transversely isotropic media
H. Chen, G. Zhang, T. Chen and X. Yin
Journal name: Geophysical Prospecting
Issue: Vol 66, No 3, March 2018 pp. 561 - 578
Info: Article, PDF ( 5.81Mb )
We propose a robust approach for the joint inversion of PP- and PSV-wave angle gathers along different azimuths for the elastic properties of the homogeneous isotropic host rock and excess compliances due to the presence of fractures. Motivated by the expression of fluid content indicator in fractured reservoirs and the sensitivity of Lam´e impedances to fluid type, we derive PP- and PSV-wave reflection coefficients in terms of Lam´e impedances, density, and fracture compliances for an interface separating two horizontal transversely isotropic media. Following a Bayesian framework, we construct an objective function that includes initial models.We employ the iteratively reweighted least-squares algorithm to solve the inversion problem to estimate unknown parameters (i.e., Lam´e impedances, density, and fracture compliances) from PP- and PSV-wave angle gathers along different azimuths. Synthetic tests reveal that the unknown parameters estimated using the joint inversion approach match true values better than those estimated using a PP-wave amplitude inversion only. A real data test indicates that reasonable results for subsurface fracture detection are obtained from the joint inversion approach.