Coupled Dynamic Flow and Geomechanical Simulations for an Integrated Assessment of CO2 Storage Impacts in a Saline Aquifer

Tillner, Elena; Shi, Ji‐Quan; Bacci, Giacomo; Nielsen, Carsten M.; Frykman, Peter; Dalhoff, Finn; Kempka, Thomas

doi:10.1016/j.egypro.2014.11.311

Cited by 38 publications

(11 citation statements)

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“…However, hydraulic properties and the spatial extent of fault damage zones are difficult to detect, and therefore exhibit a high uncertainty in predicting fault fluid flow and potentially resulting shallow freshwater salinisation (Odling et al, 2004;Harris et al, 2003). Further, geomechanical effects are relevant in the assessment of fault fluid flow and several authors have explored the impact of injection-induced pressure buildup on fault zones stability (e.g., Rinaldi et al, 2015;Kempka et al, 2014;Tillner et al, 2014;Magri et al, 2013;Röhmann et al, 2013;Cappa and Rutqvist, 2011;Chin et al, 2000). For this purpose, coupled hydro-mechanical simulations are applied to account for the interaction between hydraulic and mechanical processes, potentially triggering fault slip and dilation resulting in, e.g., new or enhanced leakage pathways for formation fluids.…”

Section: Discussionmentioning

confidence: 99%

Fault damage zone volume and initial salinity distribution determine intensity of shallow aquifer salinisation in subsurface storage

Tillner

Langer

Kempka

et al. 2016

Hydrol. Earth Syst. Sci.

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Abstract. Injection of fluids into deep saline aquifers causes a pore pressure increase in the storage formation, and thus displacement of resident brine. Via hydraulically conductive faults, brine may migrate upwards into shallower aquifers and lead to unwanted salinisation of potable groundwater resources. In the present study, we investigated different scenarios for a potential storage site in the Northeast German Basin using a three-dimensional (3-D) regional-scale model that includes four major fault zones. The focus was on assessing the impact of fault length and the effect of a secondary reservoir above the storage formation, as well as model boundary conditions and initial salinity distribution on the potential salinisation of shallow groundwater resources. We employed numerical simulations of brine injection as a representative fluid.Our simulation results demonstrate that the lateral model boundary settings and the effective fault damage zone volume have the greatest influence on pressure build-up and development within the reservoir, and thus intensity and duration of fluid flow through the faults. Higher vertical pressure gradients for short fault segments or a small effective fault damage zone volume result in the highest salinisation potential due to a larger vertical fault height affected by fluid displacement. Consequently, it has a strong impact on the degree of shallow aquifer salinisation, whether a gradient in salinity exists or the saltwater-freshwater interface lies below the fluid displacement depth in the faults. A small effective fault damage zone volume or low fault permeability further extend the duration of fluid flow, which can persist for several tens to hundreds of years, if the reservoir is laterally confined. Laterally open reservoir boundaries, large effective fault damage zone volumes and intermediate reservoirs significantly reduce vertical brine migration and the potential of freshwater salinisation because the origin depth of displaced brine is located only a few decametres below the shallow aquifer in maximum.The present study demonstrates that the existence of hydraulically conductive faults is not necessarily an exclusion criterion for potential injection sites, because salinisation of shallower aquifers strongly depends on initial salinity distribution, location of hydraulically conductive faults and their effective damage zone volumes as well as geological boundary conditions.

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Section: Discussionmentioning

confidence: 99%

Fault damage zone volume and initial salinity distribution determine intensity of shallow aquifer salinisation in subsurface storage

Tillner

Langer

Kempka

et al. 2016

Hydrol. Earth Syst. Sci.

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“…However, there are many geomechanical issues, which can take place because of pressure buildup in depleted hydrocarbon reservoirs and aquifers which may not be totally eliminated by a combined production. These geomechanical issues have been covered in numerous studies by (i) predictions of the vertical uplift due to the increase in pore pressure (Ferronato et al, 2010;Karimnezhad et al, 2014;Shi and Durucan, 2009;Shi et al, 2013;Tillner et al, 2014;Zhu et al, 2015); (ii) modelling of fault reactivations due to injection (Ferronato et al, 2010;Kim and Hosseini, 2014;Olden et al, 2012;Rutqvist et al, 2007;Tillner et al, 2014;Vidal-Gilbert et al, 2010;Zhang et al, 2015); and (iii) analysis of fractures generation within the reservoir and caprock (Alonso et al, 2012;Chiaramonte et al, 2011;Ferronato et al, 2010;Goodarzi et al, 2011;Kim and Hosseini, 2014;Lynch et al, 2013;Rutqvist et al, 2008;Shi and Durucan, 2009). For instance, Rutqvist et al (2007) proposed a fully coupled numerical analysis to estimate the maximum sustainable injection pressure for the slip tendency of faults in a twophase system considering continuum stress-strain and discrete fault assessments.…”

Section: Geomechanical Effects Related To Co2 Injection 1stress Changesmentioning

confidence: 99%

Integrity analysis of CO 2 storage sites concerning geochemical-geomechanical interactions in saline aquifers

Raza

Gholami

Sarmadivaleh

et al. 2016

Journal of Natural Gas Science and Engineering

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A systematic and careful analysis of changes in the magnitude of geomechanical parameters is essential to mitigate the risk of leakage from CO2 storage sites. However, depending on rocks and storage sites, these changes might be different due to chemical reactions taking place, especially when it comes to saline aquifers. There have only been few studies carried out in the past to evaluate the maximum sustained pressure of rocks being exposed to these chemical interactions. However, more studies are still required to evaluate the strength of the storage medium or seals when different kinds of rocks and fluids (fresh water or brine) are included in the hostile environment of a storage site. In this paper, attempts were made to evaluate changes in the variation of geomechanical parameters of the Berea sandstone during and after the injection of supercritical CO2 in a short period of time. The results obtained indicated that the presence of brine in the pore space during injection enhances the severity of geochemical reactions, causing reductions in the magnitudes of elastic parameters including shear modulus. Having a good look into the SEM images of the sample before and after exposure to scCO2 indicated that these changes can be attributed to the dissolution/fracturing of calcite and clays in the matrix of the sample. Although findings were provided based on the pulse measurements tests, more studies are required to have a deeper understanding as to how geochemical reactions may cause difficulties during and after injection into a storage site.

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“…9,10 Many coupled fluid flow and geomechanical studies have been done in the past decade to simulate the vertical ground movement, caprock fracturing, and fault reactivation in aquifers upon CO 2 injection. [11][12][13][14][15][16][17][18] There have also been many numerical 2,19-21 and experimental 22-26 studies addressing the time-dependent geomechanical integrity of sandstone aquifers. Likewise, there are also some experimental research works studying the mineral-CO 2 -brine chemical reactions in carbonate.…”

Section: Introductionmentioning

confidence: 99%

Impact of geochemical and geomechanical changes on CO₂ sequestration potential in sandstone and limestone aquifers

et al. 2019

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CO2 storage in different geological formations has been recognized as one of the promising mitigation approaches to reduce the emission of CO2 into the atmosphere. There are many complex hydro‐chemo‐mechanical interactions (effective stress changes, water acidification, and mineral dissolution) that may take place in a storage site during or after injection, reducing the integrity of formations in the short or long term. Although there have been several studies carried out in the past to assess the feasibility of sandstones and limestone formations as a safe CO2 storage site, the effect of hydrological, mechanical, and chemical processes on the storage site integrity has not been deeply addressed. The aim of this study is to couple thermo‐hydro‐chemo‐mechanical processes upon CO2 injection and assess their impact on the key storage aspects of quartz‐rich sandstone and calcite‐rich limestone. A numerical model was built to simulate CO2 flooding into a saline aquifer with sandstone and limestone composition for 500 years. The results obtained indicated that geochemical activity and CO2 dissolution are significantly higher in limestone and may increase the porosity by ∼16%. During injection, a decrease in the reservoir strength was observed in both rock types upon exposure to CO2. A remarkable variation in the geomechanical characteristics was also revealed in the sandstone after injection. However, ground displacements (subsidence) of 0.0017 and 0.033 m were, respectively, observed in sandstone and limestone aquifers, at the end of 500 years. It is recommended to consider a high‐strength reservoir for carbon capture and storage (CCS) projects in order to reduce the likelihood of compaction. It was also found that both rock types have a good storage capacity, injectivity, and trapping potentials (the structural and dissolution trappings) to capture and hold CO2 in place. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

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Coupled Dynamic Flow and Geomechanical Simulations for an Integrated Assessment of CO2 Storage Impacts in a Saline Aquifer

Cited by 38 publications

References 20 publications

Fault damage zone volume and initial salinity distribution determine intensity of shallow aquifer salinisation in subsurface storage

Fault damage zone volume and initial salinity distribution determine intensity of shallow aquifer salinisation in subsurface storage

Integrity analysis of CO 2 storage sites concerning geochemical-geomechanical interactions in saline aquifers

Impact of geochemical and geomechanical changes on CO₂ sequestration potential in sandstone and limestone aquifers

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Coupled Dynamic Flow and Geomechanical Simulations for an Integrated Assessment of CO2 Storage Impacts in a Saline Aquifer

Cited by 38 publications

References 20 publications

Fault damage zone volume and initial salinity distribution determine intensity of shallow aquifer salinisation in subsurface storage

Fault damage zone volume and initial salinity distribution determine intensity of shallow aquifer salinisation in subsurface storage

Integrity analysis of CO 2 storage sites concerning geochemical-geomechanical interactions in saline aquifers

Impact of geochemical and geomechanical changes on CO2 sequestration potential in sandstone and limestone aquifers

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Impact of geochemical and geomechanical changes on CO₂ sequestration potential in sandstone and limestone aquifers