Time-lapse seismic reservoir monitoring with a local waveform inversion technique

Abstract

The characterization of changes in a producing hydrocarbon reservoir is of importance for both fluid injection strategies and an assessment of the reservoir. In 4D seismic monitoring, a quantitative measure is obtained from changes in the acoustic medium properties, of which the parameter values are extracted from over time acquired seismic data. In this paper, full-waveform inversion is applied to tackling a class of 1.5D time-lapse seismic problems. The local linear inversion concept is at the core of the applied regularized iterative scheme, which aims at locally estimating P-wave velocity parameters from seismic data, and requires a macro velocity model that resembles the low-frequent representation of the true P-wave velocity profile. The comparative inversion results reveal substantial improvement with regard to both kinematics and dynamics after performing three nonlinear iterations. For practical interest, the employment of updated and non-updated background velocity models is addressed.