Due to the lack of stiffness coefficient c12 information in seismic data of VTI (vertical axis symmetry transverse isotropy) media, it is still challenging to obtain the brittleness index of transversely isotropic (BIVTI) directly from seismic data. In this paper, we established the approximate relation c12 by using the rock physics model, and obtained BIVTI directly from seismic data based on the exact reflection coefficient equation. Firstly, we first derive an approximate expression for c12 through shale rock physics analysis. Secondly, we have proposed a method for obtaining BIVTI from seismic data using the Graebner exact reflection coefficient equation. This methoud considers the influence of horizontal slowness and deriving a more accurate Jacobian Matrix. Finally, we established the inversion method using model well tests, demonstrating the method’s superior precision and noise resistance. Compared with the traditional brittleness index, BIVTI obtained by the inversion method can better characterize the reservoir brittleness.

This content is only available via PDF.
You can access this article if you purchase or spend a download.