Geo-Mechanical Weakening of Limestone Due to Supercritical CO2 Injection

Zhang, Yihuai; Sarmadivaleh, Mohammad; Lebedev, Maxim; Barifcani, Ahmed; Rezaee, Reza; Testamanti, M. Nadia; Iglauer, Stefan

doi:10.4043/26470-ms

Cited by 18 publications

(4 citation statements)

References 15 publications

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“…Two Savonnieres limestone cores were obtained from a quarry in the North-East of France (Lorraine region). Savonnieres limestone is a widely used standard carbonate rock used in many published studies of petrophysical and flow properties [27][28][29][30][31] . The XRD results of the rock show that the cores are almost entirely composed of calcite (>99%).…”

Section: Methodsmentioning

confidence: 99%

Pore Structure Changes Occur During CO2 Injection into Carbonate Reservoirs

Seyyedi

Mahmud

Verrall

et al. 2020

Sci Rep

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observations and modeling studies have shown that during co 2 injection into underground carbonate reservoirs, the dissolution of co 2 into formation water forms acidic brine, leading to fluid-rock interactions that can significantly impact the hydraulic properties of the host formation. However, the impacts of these interactions on the pore structure and macroscopic flow properties of host rock are poorly characterized both for the near-wellbore region and deeper into the reservoir. Little attention has been given to the influence of pressure drop from the near-wellbore region to reservoir body on disturbing the ionic equilibrium in the co 2-saturated brine and consequent mineral precipitation. In this paper, we present the results of a novel experimental procedure designed to address these issues in carbonate reservoirs. We injected CO 2-saturated brine into a composite core made of two matching grainstone carbonate core plugs with a tight disk placed between them to create a pressure profile of around 250 psi resembling that prevailing in reservoirs during CO 2 injection. We investigated the impacts of fluid-rock interactions at pore and continuum scale using medical X-ray CT, nuclear magnetic resonance, and scanning electron microscopy. We found that strong calcite dissolution occurs near to the injection point, which leads to an increase in primary intergranular porosity and permeability of the near injection region, and ultimately to wormhole formation. The strong heterogeneous dissolution of calcite grains leads to the formation of intra-granular micro-pores. At later stages of the dissolution, the internal regions of ooids become accessible to the carbonated brine, leading to the formation of moldic porosity. At distances far from the injection point, we observed minimal or no change in pore structure, pore roughness, pore populations, and rock hydraulic properties. The pressure drop of 250 psi slightly disturbed the chemical equilibrium of the system, which led to minor precipitation of sub-micron sized calcite crystals but due to the large pore throats of the rock, these deposits had no measurable impact on rock permeability. The trial illustrates that the new procedure is valuable for investigating fluid-rock interactions by reproducing the geochemical consequences of relatively steep pore pressure gradients during co 2 injection. Capturing CO 2 from large industrial sources and storing it in geological formations, such as saline aquifers, and depleted oil and gas fields, has become widely accepted as a viable solution for reducing high CO 2 levels in the atmosphere 1-3. Among underground formations, carbonate reservoirs are attractive CO 2 sequestration options, as the majority of the world's oil reserves (60%) are held in these types of rocks (especially in the Middle East), making them a primary storage target when combined with enhanced oil recovery (EOR) operations 4. Furthermore, since these reservoirs could hold the hydrocarbons for millions of years, it can be assumed that they can hold the CO ...

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Section: Methodsmentioning

confidence: 99%

Pore Structure Changes Occur During CO2 Injection into Carbonate Reservoirs

Seyyedi

Mahmud

Verrall

et al. 2020

Sci Rep

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“…Civan reported that particle bridging can only occur if the ratio (β) of the pore throat to particle diameter is less than 7. − As a result, the permeability can decreases if β < 7 ,,,,,, or increase if β > 7, ,,,, owing to changes in the pore throat size as a result of fine migration. Changes in permeability are thus often expected when clay minerals are present in the sample.…”

Section: Resultsmentioning

confidence: 99%

Permeability Evolution in Sandstone Due to CO₂ Injection

Al-Yaseri¹,

Zhang²,

Ghasemiziarani³

et al. 2017

Energy Fuels

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Permeability variation is one of the key factors influencing the injectivity of CO 2 in CO 2 sequestration projects. Despite the research carried out on the subject, the results are highly inconsistent. In this study, the injection of brine (5 wt % NaCl + 1 wt % KCl), CO 2 -saturated (live) brine, and supercritical CO 2 was performed on three homogeneous Berea sandstone plugs with a low clay content and two Bandera Gray sandstone plugs with a high clay content at reservoir conditions (10 MPa and 323 K). Porosity and permeability of the samples were measured using nuclear magnetic resonance (T 2 relaxation time), and a dynamic (during flooding) permeability measurement technique, respectively, at different injection rates and injection durations. The mercury intrusion test was also performed on each sample to further evaluate its pore throat size distributions.From the results of this study, it was revealed that the CO 2 injection rate is unlikely to affect the permeability significantly. It was also shown that the permeability can be influenced depending upon sandstone pore throat size distribution and the distribution/ structure of the clay minerals in the sample.

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“…There have also been many numerical and experimental 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 . However, minor attention has been given to the impact of changes in the strength of calcite‐rich limestone and quartz‐rich sandstone upon CO 2 injection.…”

Section: Introductionmentioning

confidence: 99%

“…Likewise, there are also some experimental research works studying the mineral-CO 2 -brine chemical reactions in carbonate. [27][28][29][30][31] However, minor attention has been given to the impact of changes in the strength of calcite-rich limestone and quartz-rich sandstone upon CO 2 injection. The aim of this study is to propose a numerical model where the thermo-hydro-chemo-mechanical processes could be coupled to evaluate the feasibility of sandstone and carbonate aquifers as potential CO 2 sequestration sites.…”

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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Geo-Mechanical Weakening of Limestone Due to Supercritical CO2 Injection

Cited by 18 publications

References 15 publications

Pore Structure Changes Occur During CO2 Injection into Carbonate Reservoirs

Pore Structure Changes Occur During CO2 Injection into Carbonate Reservoirs

Permeability Evolution in Sandstone Due to CO₂ Injection

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

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Geo-Mechanical Weakening of Limestone Due to Supercritical CO2 Injection

Cited by 18 publications

References 15 publications

Pore Structure Changes Occur During CO2 Injection into Carbonate Reservoirs

Pore Structure Changes Occur During CO2 Injection into Carbonate Reservoirs

Permeability Evolution in Sandstone Due to CO2 Injection

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

Contact Info

Product

Resources

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Permeability Evolution in Sandstone Due to CO₂ Injection

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