NUMERICAL SIMULATION METHODOLOGY FOR EVALUATING REGIONAL CO2 STORAGE IN THE ARCHES PROVINCE OF THE MIDWESTERN UNITED STATES

The Arches Simulation project’s overall objective is to develop a simulation framework for regional geologic CO₂ storage infrastructure along the Arches Province of the Midwestern United States. The Arches Province includes areas in northern Indiana, northern Kentucky, western Ohio, and southern Michigan where Paleozoic rocks form broad arch and platform structures. This province has the potential to accommodate large-scale CO₂ storage in the Mount Simon Sandstone (Cambrian), which has been used for deep well injection for many decades. The Mt. Simon sandstone is the main injection target for CO₂ storage due to its depth, thickness, hydraulic properties, and brine salinity, and because of the existence of the overlying Eau Claire Formation confining layer. In addition, there are many existing CO₂ sources in proximity to the Arches Province, including the Ohio River Valley corridor of coal-fired power plants. This simulation framework is based on a geocellular conceptual model with geostatistically generated porosity and permeability distributions developed for the Mount Simon Sandstone and the overlying Eau Claire Formation (Cambrian) confining layer based on geophysical well logs, deep injection operational data from wells, reservoir test results, and geotechnical core test data. This conceptual model consisting of 50 million cells was upscaled and mapped to a variably spaced, boundary-fitted numerical mesh that preserves the structural surfaces of the geologic layers and variations in the thickness of units. This is particularly important for modeling the pressure distribution in the Arches Province because of the very large structural relief in the area. The numerical mesh was refined in the areas of seven potential regional storage site locations, selected on the basis of GIS analyses that balanced the location of stationary CO₂ sources with existing pipeline networks. CO₂ injection in networks of wells located at each of these seven sites was simulated with the STOMP-CO2 multiphase simulator to evaluate the implications of CO₂ storage on the regional pressure buildup, brine migration and CO₂ plume development.

This work was supported by U.S. Department of Energy National Energy Technology Laboratory award DE-FE0001034 and Ohio Department of Development grant D-10-03.