Dynamic reservoir characterization using 4D multicomponent seismic data and rock physics modeling at Delhi Field, Louisiana.

摘要

Pore pressure and CO₂ saturation changes are important to detect and quantify for maximizing oil recovery in Delhi Field. Delhi Field is a enhanced oil recovery (EOR) project with active monitoring by 4D multicomponent seismic technologies.;Dynamic rock physics modeling integrates the rich dataset of core, well logs, petrographic thin sections and facies providing a link between reservoir and elastic properties. The dynamic modeling in this high porosity sandstone reservoir shows that P-wave velocity is more sensitive to CO₂ saturation while S-wave velocity is more sensitive to pore pressure changes. I use PP and PS seismic data to jointly invert for Vp=Vs ratio and acoustic impedance. This technique has the advantage of adding more information to the non-unique inversion problem. Combining the inversion results from the monitor surveys of June 2010 and August 2011 provides acoustic impedance and Vp=Vs percentage differences. The time-lapse inverted response enables dynamic characterization of the reservoir by fitting the predicted dynamic models (calibrated at the wells).;Dynamic reservoir characterization adds value in this stratigraphic complex reservoir. The results indicate that reservoir heterogeneities and pore pressure gradients control the CO₂ flow within the Paluxy reservoir. Injectors 148-2 and 140-1 showed CO₂ is moving downdip following a distributary channel induced by differential pressure from an updip injector or a barrier caused by a heterogeneity in the reservoir. CO₂ anomalies located above the Paluxy injector 148-2 indicates that CO₂ is moving from the Paluxy up into the Tuscaloosa Formation. My work demonstrates that reservoir monitoring is necessary for reservoir management at Delhi Field.