Estimating Reservoir Properties from 4D Seismic Data

摘要

Method for deriving a reservoir property change data volume from time shifts used to time-align 4D seismic survey data (31). The time alignment is performed on at least one angle stack of 4D data to determine a time-shift data volume (32). When multiple angle stacks are used, the time shifts are corrected to zero offset. A running time window is defined, and within each window the time shifts are best fit to a straight-line function of time (depth), one angle stack at a time (33). The slopes from the straight line fits from different angle stacks are averaged at each voxel in the data volume, which yields a reservoir properties (Δv/v) data volume (34). This data volume may be filtered with a low-pass filter to improve signal-to-noise (35). The resulting data volume may be merged with the 4D data volume to expand its bandwidth (36), or it may be converted into a reservoir saturation and pressure change data volume (38) using a rock-physics model (37).