Product Summary

National Risk Assessment Partnership (NRAP) Testing and Validation: Part 1 NRAP Open-Source Integrated Assessment Model (OPEN-IAM)

The Energy & Environmental Research Center tested and validated the National Risk Assessment Partnership (NRAP) Open-source Integrated Assessment Model (Open-IAM). This report presents the results of these efforts, which were conducted under the PCOR Partnership. The NRAP testing and validation plans of the PCOR Partnership currently include two NRAP tools: i) Open-IAM and ii) Designs for Risk Evaluation and Management (DREAM). The testing and validation of these tools are intended to support their ongoing development. In particular, the testing is assessing the ability of the Open-IAM and DREAM tools to support decision-making for a CO₂ storage project considering compliance with the Safe Drinking Water Act requirements. The testing outputs for each tool will be summarized in a report that documents the specific version of the tool, input files and assumptions, output files, and recommendations for improving the tool. This Open-IAM testing summary report is Part 1 of 2 of Deliverable D10(NRAP Testing and Validation). A second summary report (Part 2 of 2 of Deliverable D10) specific to DREAM will be prepared at a later date. These summary reports for each tool will be consolidated into a single report, Deliverable D10. The Open-IAM version alpha 2.2.0-21.02.12, which required installation of Python version 3.7.6-amd64, was tested. It incorporated a generalized stratigraphy of the primary hydrostratigraphic units for the Williston Basin, North Dakota, and reservoir simulations of pressure and CO₂ saturation designed to reflect a clastic shelf depositional environment with four CO₂ injection wells and a target CO₂ mass injection rate of 4 million metric tons of CO₂ per year. Six Open-IAM components were included in the test program: i) Model Component: outlines model parameters that include simulation name, end time, time step, types of simulation and/or analysis, and output directory; ii) Stratigraphy Component: defines the stratigraphy of the storage complex that includes the thickness of the storage reservoir and overlying hydrostratigraphic units; iii) Lookup Table Reservoir Component: consists of a reduced-order model (ROM), which is based on the interpolation of inputs from a set of lookup tables that are created from the reservoir simulation results for pressure and CO₂ saturation; iv) Multisegmented Wellbore Component: allows the Open-IAM to assign multiple hypothetical leaky wells as potential vertical leakage pathways that connect the storage reservoir to the overlying aquifers in the storage complex; v) FutureGen 2.0 Above Zone Monitoring Interval (AZMI) Component: consists of a ROM, which is recommended for aquifers with depths ranging from 700 to 1600 m and an aquifer thickness ranging from 30 to 90 m, that models the dissipation interval between the storage reservoir and the lowermost underground source of drinking water (USDW) and predicts the size of "impact plumes" according to five metrics (pH, total dissolved solids [TDS], pressure, dissolved CO₂, and temperature) and defines their volume (m³) and dimensions (m) in the x- (length), y-(width), and z-direction (height); and vi) FutureGen 2.0 Aquifer Component: consists of a ROM, which is recommended for aquifers with depths ranging from 100 to 700 m and an aquifer thickness ranging from 30 to 90 m, that models the USDW and predicts the size of "impact plumes" according to four metrics: pH, TDS, pressure, and dissolved CO₂. This report provides step-by-step instructions and input files for reproducing the Open-IAM testing, summarizes the Open-IAM simulation results for brine and CO₂ leakage, and presents key findings to support the ongoing development of the Open-IAM.