Study on inversion of permeability for transversely isotropic porous media by dipole fiexural waves in a borehole

The theoretical method and numerical study which inverses the vertical and horizontal permeability of the transversely isotropic porous media has been done in this paper by using the attenuation character of dipole flexural waves in a borehole. For the slow formation, based on behavior analysis of the variance function, the precision of vertical and horizontal permeability is relatively high which is calculated to groups of theoretical simulation data by least squares method, this is related to the sensitivity of horizontal permeability to the attenuation of slow formation is more than which of fast formation. Though the random noise of different intensity is added to simulate the error of the actual data of well logging, the influence of noise still can be offset by superposition averaging of the attenuations which is calculated from multi-channel. For the fast formation, the vertical and horizontal permeability has been also attempted to inverse by the theoretical simulation data. It is also found that although the vertical permeability of fast porous formation is hardly sensitive, the result of horizontal permeability will be impacted if the value of vertical permeability is much more different from the real value.