Fit-for-Purpose Brine Extraction Storage Test (BEST) field projects have been initiated to address reservoir pressure management. According to extensive modeling studies, several potential geomechanical and hydrologic impacts of carbon dioxide (CO2) storage are directly related to reservoir pressure changes that accompany the injection of large volumes of fluid into the deep subsurface.
For example, in deep saline reservoirs, pressure increases due to injection can potentially increase the risk of induced seismicity, limit injection rates, or drive vertical brine migration through leakage pathways (e.g., abandoned wells) that could impact sources of drinking water. Modeling has shown that extraction of brine is a promising approach for mitigating these impacts by reducing reservoir pressure increases and their spatial extent. In addition, the technique could also be employed for geosteering, which is to steer the CO2plume or pressure front (e.g., to avoid interaction of a fault with the CO2 plume or pressure increases in the fault).
Research Agenda and Challenges
The common objective of the two active BEST field projects is to develop and validate brine extraction strategies/approaches for managing changes in storage reservoir pressure while incorporating innovative treatment and re-use technologies for the extracted brines. Working at field sites provided by industrial partners, the research involves the injection and extraction of brine from deep saline formations, predictive modeling of the differential pressure plume (differential pressure is defined as the difference in pressure at a point in the reservoir before and after injection begins), and monitoring to validate pressure management approaches. Extracted brines will be utilized as a part of a test bed for brine treatment technologies.
More information on BEST Projects can be found on the Carbon Storage Project Portfolio Page under “Fit-for-Purpose Projects.”