Dr. Charles Hostetler is presenting on Wednesday, February 28th (11:00 am – 11:30 am, Century).
“Pore Space Conflicts: Class VI Injection into Previously Utilized Pore Space”
Class VI projects (involving underground injection control (UIC) wells for the geologic sequestration of carbon dioxide) can have a surprisingly large footprint in terms of the lateral extent of pore space occupied by supercritical carbon dioxide as well as pressure increases in the injection zone. A limited amount of subsurface pore space is available in certain economically important sedimentary basins and there can be difficulties in finding unutilized pore space.
Interactions among neighboring UIC projects can be an important consideration in the scoping and design of Class VI projects. Class VI project design has largely focused on examining the extent of the subsurface supercritical carbon dioxide plume and ensuring access to and control over the pore space physically occupied by the plume. The pressure buildup during injection also influences subsurface pore space. The existence of pressure buildup from neighboring injection projects can be an important limitation in efficiently utilizing pore space resources across multiple projects.
In this study, we examine the factors that affect the injectability of a supercritical carbon dioxide stream near a preexisting Class I (liquid waste) UIC well. We consider the factors that influence the pressure distribution in the injection zone, such as the compressibility of water and supercritical carbon dioxide, the properties of the aquifer materials, and the geometry of the injection zone and injection wells. We conclude by summarizing the general factors that should be considered in project scoping and Area of Review delineation—additional authors: Kacey Garber and Lindsey Hawksworth, SCS Engineers.