Large-Scale CO2 Pipeline Network Optimization Based on a Basin Geospatial Splitting Approach

Abstract

Transport infrastructure for CO2 is the backbone of carbon capture and storage (CCS) technology for mitigating carbon emissions. To facilitate large-scale CCS project deployments, optimal CO2 transport pipeline networks are required to connect multiple CO2 emission sources and subsurface storage sites. However, in large-scale CO2 pipeline network designs, the centroids of geologic storage basins are assumed to represent sink locations. Although this assumption can simplify the optimization process, it might provide non-optimal solutions because some storage basins extend ~100s to ~1000s square miles. To address this situation, we developed a novel geospatial splitting framework that partitions large basins into multiple sub-basins to optimize the transportation of CO2 from the point sources to the storage sites. To determine the number of subregions for each basin, we initially generated multiple reservoir models by varying geological properties such as porosity, permeability, and storage zone thickness. These models were numerically simulated with different CO2 injection rates to compute pressure plumes and estimate pressure interference areas and boundaries. Second, we used K-means clustering and Voronoi polygon algorithms for the geospatial partitioning and definition of the physical boundaries of the new subregions, which are determined based on the ratio of the extent of the pressure plume and the original basin size. Finally, the design of the best pipeline routes was conducted with SimCCS3.0 establishing the annual capture amounts as the target objectives. To demonstrate the value of our workflow, we modeled two scenarios in the Intermountain West region of the U.S. The use of the splitting approach resulted in a total pipeline length decrease of 355 miles and a reduction cost of $2.7 billion in comparison to the model with the original basins. Additionally, simple pipeline networks and small diameters were obtained, revealing that the location of point sinks has a critical impact on CO2 pipeline infrastructure. The workflow is a new optimization feature for the correct design of CO2 pipeline routes, serving as a complementary modeling method for CO2 transport and storage in carbon management strategies.

Keywords: CO2 pipelines optimization, Carbon capture and storage, CO2 sequestration deployment, CO2 transport infrastructure