Modeling of the Co2 Geological Storage at the S3 Site (sim-seq Comparative Project)

The Sim-SEQ project coordinated by the Lawrence Berkeley National Laboratory (LBNL) aims at providing a comparative study of different conceptual models with respect to predicting the behavior of CO2 geological storage operations conducted on a reservoir formation, while using the same database for site characterization. The S-3 site has been selected for conducting such a comparative study. All site characterization and operational data for the S-3 site are supplied by the Bureau of Economic Geology (BEG) at the University of Texas at Austin. The site is a depleted oil and gas field, located in the Mississippi Gulf Coast (United States), at which CO2 injection started in November 2009. Being one of the participating modeling teams, BRGM proposed to provide a complete assessment of the field by generating a 3D static earth geological model using the Petrel reservoir geomodeler, and by using an in-house toolbox to convert the 3D mesh of the static model into TOUGH2 and TOUGHREACT formats, before generating a multiphase flow simulation of the CO2 injection. The geological model is constructed based on information provided by several well log data. Horizon surface is rebuilt, and fluvial sandstone-shale facies distribution is generated. Reservoir petrophysical properties are associated to each facies in agreement with the provided data (absolute and relative permeability and capillary pressure), as well as temperature and salinity. Hydrostatic pressure and temperature gradient is recalculated before the simulation of the CO2 injection. Calibration of the model is performed by comparing results from the simulated scenario with observation-well data provided in the project. The geochemistry of the water and the mineralogy description of the rock will serve as perspectives in evaluating the fluid-rock-interaction evolution of the system for the tens-ofyears injection and post-injection period. This paper provides details on the methodology and preliminary results regarding the static geological model and dynamic flow simulation.