LI Xiansheng, LIU Xiangjun, LIANG Lixi, et al. Correction methods for acoustic anisotropy of bedding shale[J]. Petroleum Reservoir Evaluation and Development, 2020, 10(5): 49-54. DOI: 10.13809/j.cnki.cn32-1825/te.2020.05.007.
Correction methods for acoustic anisotropy of bedding shale
The physical and mechanical properties of bedding shales show strong anisotropy
which leads to the significant difference in the logging response of the same formation between the vertical wells and the horizontal wells
and bringing the difficulties in regional reservoir evaluation. Based on the numerical simulations
the influence of orientation and density of bedding on the anisotropy of longitudinal wave has been analyzed
and a correction model for longitudinal wave of shale in Longmaxi formation has been built. Then
combined with the indoor compression wave experiment
the rationality of this new model has been analyzed. The results show that
the longitudinal wave anisotropy of shales in Longmaxi formation is obvious
and the coefficient of longitudinal wave is around 1.088 ~ 1.109. The coefficient of longitudinal wave anisotropy has a quadratic polynomial relation with the sine of the bedding angle
and the anisotropic coefficient increases linearly with the increase of bedding density. Application examples show that this new model can reasonably correct the acoustic response of horizontal wells to that of vertical wells.