A Compositional Sim2Seis Workflow for Modelling CO2 Dissolution Effects on 4D Seismic Data

We demonstrate a Sim2Seis workflow to model 4D seismic data from compositional reservoir simulation results involving CO2 injection into subsurface reservoirs. This workflow includes CO2 dissolution effects into the three fluid phases, oil, water and gas. We quantify the magnitude of CO2 dissolution effects on 4D seismic data by comparing with a Sim2Seis workflow that neglects dissolution. The study is applied to two reservoir models with compositional simulations of CO2 storage: a saline aquifer and a depleted gas-condensate reservoir. The study concludes that CO2 dissolution effects on 4D seismic are generally small compared to saturation change effects. However, in certain reservoir settings, it may be enough to affect the conclusions of a 4D seismic feasibility study.