AVAZ inversion for fluid factor based on fracture anisotropic rock physics theory

The fractured reservoirs show strong anisotropy. When the fracture is filled with different types of fluids, the seismic response characteristics of fractured reservoir are not the same. Starting from the anisotropic rock physics theory, this article introduces the identification factor that can effectively distinguish fracture fluid; studies the relationship of fluid factor to fluid types, saturation and crack aspect ratio; analyzes the seismic response characteristics when the fracture is full of different fluids; and ultimately puts forward the method to estimate the crack fluid factor based on AVAZ inversion. Firstly, the sensitivity of crack fluid factor is analyzed in this paper. Secondly, the features of fluid factor and fractured reservoir's reflection coefficient variation when the fracture is filled with different types of fluids are discussed. At last, well-log data and complex fracture model are used to verify the inversion method. The results show that the method to estimate the crack fluid factor is reasonable and reliable. And the estimation results of the fluid factor can match the true value well when the synthetic seismic traces contain a random noise.