Active CO₂ reservoir management for sustainable geothermal energy extraction and reduced leakage

Abstract

Subsurface storage space is gaining recognition as a commodity for industrial and energy recovery operations. Geologic carbon dioxide (CO2) sequestration (GCS), wherein supercritical CO2 is injected into subsurface storage space, is under broad development in sedimentary reservoirs – particularly for hydrocarbon production, which uses supercritical CO2 as part of a carbon capture utilization and sequestration (CCUS) scheme. A novel CCUS operation is presented whereby we investigate the staged deployment of a coupled geothermal energy extraction (GEE)‐GCS operation in geothermal sedimentary reservoirs that re‐circulates extracted fluids. We identify sedimentary resources of the continental USA that have significant temperature at depths suitable for GCS. To predict the impact of a GEE‐GCS operation, a reservoir‐scale semi‐analytical model is used to simulate brine and CO2 migration through existing leakage pathways. With the goal of integrating GEE and GCS, a well‐site design exercise is undertaken, where we develop an idealized configuration for CO2 and brine production/reinjection wells. Results show potential geothermal sedimentary reservoirs suitable for GEE deployment exist in the continental USA; however the characteristics of each site should be investigated through a first stage GEE‐operation to determine GCS capacity. Our active CO2 reservoir management simulations demonstrate a decrease in injection and reservoir overpressures, a reduced migration of CO2 within the reservoir during active injection/extraction, and a reduced risk of brine and CO2 migration. With the use of the developed concentric‐ring well pattern, we demonstrate the longevity of thermal productivity from an ideal GEE site, while providing sufficient CO2 storage volume and trapping to act as a sequestration operation. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd

Status of CO2storage in deep saline aquifers with emphasis on modeling approaches and practical simulations

“…[] and Elliot et al . [] also investigated how production wells could be used for geothermal energy, with a focus on well locations and coupled thermal and CO 2 breakthrough considerations.…”

High performance reactive transport simulations examining the effects of thermal, hydraulic, and chemical (THC) gradients on fluid injectivity at carbonate CCUS reservoir scales

“…The presence of background hydraulic head gradients in subsurface aquifers can also determine the effectiveness of supercritical CO 2 storage, particularly by the capillary trapping mechanism (MacMinn et al, 2010). Furthermore, where required, CO 2 -based geothermal energy reservoir operators may also engineer hydraulic head gradients by pumping fluids into or out of the reservoir to manage the flow of CO 2 in the subsurface and its thermal exchange with the reservoir (Buscheck et al, 2011(Buscheck et al, , 2012Elliot et al, 2013).…”

Multifluid geo-energy systems: Using geologic CO2storage for geothermal energy production and grid-scale energy storage in sedimentary basins

“…The system consists of a 125-m-thick reservoir with a permeability of 1 × 10 -13 m 2 , bounded by low-permeability seal units (caprock and bedrock), each with a permeability of 1 × 10 -18 m 2 . Hydrologic properties (Table 1) are similar to previous GCS and multifluid geo-energy studies (Zhou et al, 2008;Buscheck et al, 2013aBuscheck et al, , 2013bBuscheck et al, , 2013cBuscheck et al, , 2014aBuscheck et al, , 2014bBuscheck et al, , 2015Saar et al, 2015;Elliot et al, 2013). Because the reservoir, the caprock, and the bedrock are assumed to be laterally homogeneous, we use a radially symmetric (RZ) model.…”