Increasing CO2-Storage Efficiency through a CO2-Brine Displacement Approach

Abstract

Previous studies have shown that bulk CO 2 injection in deep saline aquifers supplies insufficient aquifer storage efficiency and causes excessive risk due to aquifer pressurization. To avoid pressurization, we propose to produce the same volume of brine as is injected as CO 2 in a CO 2 -brine displacement. Previous work showed that this increases the storage efficiency from 2% to 8%. However, this transforms the CO 2 storage problem into a brine disposal problem. Therefore, we propose to desalinate the native brine and inject the saturated brine into the same aquifer while producing additional brine to maintain voidage balance.A hypothetical case study using documented aquifer properties of the Woodbine aquifer in Texas indicates that the available volume is insufficient volume to store all of the CO 2 being generated by power plants in the vicinity for more than 14 years. However, the CO 2 -brine displacement increases storage efficiency enough to store the CO 2 produced for 84 years at the current rate of coal fired electric power generation. Using the reported brine salinity of the Woodbine aquifer, the energy requirements for CO 2 transport and injection, brine production and transport, desalination, and saturated brine injection are estimated consistent with assumptions about the location of injection and production wells, the desalination unit or units, and whether desalinated water can be used by the power plant or for other uses.While this approach may enable CO 2 storage, the high energy cost ranging from 7.5% to 16% of the total power generation capacity is not insignificant, and comes with significant land use implications for injection and production wells, pipelines, etc. The importance of these results cannot be overstated.

Experimental Study on a Novel Foaming Formula for CO2 Foam Flooding

“…Another advantage of dense CO2 as a displacement fluid is its extremely low solubility in formation water, preventing an excessive amount of the CO2 from being lost when CO2 flooding is performed in water-flooded reservoirs. Moreover, capturing and injecting CO2 into the petroleum-bearing underground will greatly reduce the greenhouse gas (GHG) effect as well as produce oil, which also makes the CO2 flooding a compelling enhanced oil recovery (EOR) strategy [8][9][10].…”

Economic Modelling of CO2 Injection for Enhanced Gas Recovery and Storage: A Reservoir Simulation Study of Operational Parameters

“…First of all, in terms of cost, some capital expenditures associated with drilling, completion and equipment have been extracted based from recent published data (Akinnikawe et al, 2010). The costs originally were produced by Join Association Survey (JAS) and recently been updated and published by Advanced Resource International (ARI).…”