Inversion of carbonate-rock properties based on an acoustoelasticity-squirt flow model

SUMMARY Deep carbonate reservoirs are characterized by complex stress states and pore structures, and frame compressibility is strongly influenced by differential pressure. We have developed a frequency-dependent acoustoelasticity-squirt flow model based on a threshold pressure to describe the frame compressibility. Based on this model, 3-D rock physics templates were created and calibrated with laboratory, well log and seismic data from the Longwangmiao Formation in the Gaoshiti-Moxi area, Sichuan Basin, China. The templates are then used to determine the reservoir properties at the well logging and seismic frequencies. The predicted porosity matches well with the actual porosity log curve, and the results are consistent with gas production reports, with high porosity, crack density and threshold pressure (high-frame compressibility) indicating high reservoir potential.