Using pressure and volumetric approaches to estimate CO2 storage capacity in deep saline aquifers
article
Various approaches are used to evaluate the capacity of saline aquifers to store CO2, resulting in a wide range of capacity
estimates for a given aquifer. The two approaches most used are the volumetric “open aquifer” and “closed aquifer” approaches.
We present four full-scale aquifer cases, where CO2 storage capacity is evaluated both volumetrically (with “open” and/or
“closed” approaches) and through flow modeling. These examples show that the “open aquifer” CO2 storage capacity estimation
can strongly exceed the cumulative CO2 injection from the flow model, whereas the “closed aquifer” estimates are a closer
approximation to the flow-model derived capacity.
An analogy to oil recovery mechanisms is presented, where the primary oil recovery mechanism is compared to CO2 aquifer
storage without producing formation water; and the secondary oil recovery mechanism (water flooding) is compared to CO2
aquifer storage performed simultaneously with extraction of water for pressure maintenance. This analogy supports the finding
that the “closed aquifer” approach produces a better estimate of CO2 storage without water extraction, and highlights the need for
any CO2 storage estimate to specify whether it is intended to represent CO2 storage capacity with or without water extraction
estimates for a given aquifer. The two approaches most used are the volumetric “open aquifer” and “closed aquifer” approaches.
We present four full-scale aquifer cases, where CO2 storage capacity is evaluated both volumetrically (with “open” and/or
“closed” approaches) and through flow modeling. These examples show that the “open aquifer” CO2 storage capacity estimation
can strongly exceed the cumulative CO2 injection from the flow model, whereas the “closed aquifer” estimates are a closer
approximation to the flow-model derived capacity.
An analogy to oil recovery mechanisms is presented, where the primary oil recovery mechanism is compared to CO2 aquifer
storage without producing formation water; and the secondary oil recovery mechanism (water flooding) is compared to CO2
aquifer storage performed simultaneously with extraction of water for pressure maintenance. This analogy supports the finding
that the “closed aquifer” approach produces a better estimate of CO2 storage without water extraction, and highlights the need for
any CO2 storage estimate to specify whether it is intended to represent CO2 storage capacity with or without water extraction
TNO Identifier
521796
Source
Energy Procedia, 63, pp. 5294-5304.
Pages
5294-5304