Challenges of designing, operating, and managing brine extraction at a carbon dioxide storage site

Developing and deploying commercial-scale carbon dioxide (CO₂) storage at a site requires operational strategies to manage pressure and CO₂ plume distribution. In the natural gas storage and oil and gas industries, fluid extraction has been successfully implemented as a strategy to manage pressure and control fluid distribution (i.e., hydrocarbon recovery and natural gas storage efficiency, respectively). The technical challenges of integrating brine extraction at CO₂ storage sites are expected to be similar, if not identical, to those in the natural gas storage and petroleum industries. Major technical challenges of using brine extraction to manage storage in a storage unit include (1) designing and completing the brine extraction wells, (2) locating the brine extraction well, (3) assessing the efficacy of brine extraction, and (4) handling the extracted brine. The design and completion of the brine extraction well include the well type (i.e., vertical or horizontal) and perforated interval. The location of the well is influenced by the timing of extraction operations (i.e., prior or after CO₂ injection starts) and project objectives (i.e., desired directional movement of the CO₂ plume and avoid or minimize CO₂ extraction). The efficacy of brine extraction requires a baseline projection of the pressure and CO₂ plume distribution. Options for handling extracted brine include subsurface disposal, surface disposal, and industrial use. This paper addresses means of overcoming technical challenges that may likely be encountered before or after CO₂ injection starts.