Mark Kelley

Ordovician Knox Carbonates and Sandstones of the Eastern Mid-continent: Potential Geologic Carbon Storage Reservoirs and Seals

In response to rising concerns about atmospheric carbon dioxide (CO2) levels and likely regulations on emissions, investigations into geologic carbon storage options across the United States are underway. In the Midwest, Cambrian sandstones are major targets for potential geologic carbon storage. In some localities, the overlying Cambrian–Ordovician Knox Group is also being investigated as a possible target for primary and secondary storage of CO2. The thick dolomitic succession contains intervals that may function as both reservoirs and seals. Gas storage fields in Knox carbonates in Kentucky and Indiana demonstrate that methane can be safely stored in paleotopographic highs along the Knox unconformity surface. Numerous injection wells have also been completed in the Knox Group for brine disposal. More significantly, at least seven class 1 injection wells have used the Knox as all or part of a storage reservoir for industrial wastes. Many of these wells have injected millions of gallons of liquid waste annually into Knox reservoirs. The relative scale of these injection operations can be used to estimate the types and sizes of potential reservoirs within the Knox succession in the Midwest. Specific data on the Knox interval relative to its carbon storage and confining potential are currently being collected from wells drilled as part of U.S. Department of Energy administered carbon storage projects, as well as state-administered carbon storage programs. In this chapter, initial results of carbon storage tests are summarized from the Battelle 1 Duke Energy well, Kentucky Geological Survey 1 Blan well, Battelle-American Electric Power (AEP) 1 Mountaineer well, and Battelle-Ohio Geological Survey 1 CO2 well. The AEP Mountaineer Power Plant will host the nations first commercially integrated carbon capture and geologic storage project, and the storage reservoirs will be in the Knox Group. Because the Knox Group is widespread at depth across much of the Midwest, it will be an important part of sequestration programs as confining interval and reservoir.

Assessment of CO2 injection at the mountaineer power plant site using scalable numerical simulation

Publisher Summary Numerical simulations of carbon dioxide (CO 2 ) injection are conducted as a part of a comprehensive program to assess the potential for geologic sequestration in deep geologic reservoirs at the American Electric Powers (AEPs) Mountaineer Power Plant site in West Virginia. Initial assessments of the site geology indicated two potential injection reservoirs—the Rose Run and Lower Marysville formation. The Rose Run formation is simulated, considering the dolomite confining and interbedding units explicitly, using three geologic conceptual models for intrinsic permeability and porosity: homogeneous, core-sample-stochastic, and wireline stochastic. The Copper Ridge formation is simulated using stochastically generated geology from the wireline and borehole field testing data. The confining layers above and below the Copper Ridge formation are not explicit modeled and are assumed impermeable. Subsequent borehole field testing has identified an additional potential injection reservoir in the Copper Ridge formation. This chapter presents a pilot study to predict CO 2 injection rates over a 20-year injection period and CO 2 distributions over a 100-year injection and redistribution period for two potential brine reservoir—the Rose Run and Copper Ridge formations. Simulations of CO 2 injection and redistribution were conducted for both the single-vertical and double-horizontal injection wells. Single-vertical well simulation scenarios assumed radial symmetry using a two-dimensional radial domain centered on the vertical injection well, extending radially to 8 km. Double-horizontal injection wells assumed planar symmetry, normal to the horizontal well and centered on the vertical well using three-dimensional domains that extended from the vertical well to 8 km.