Mechanism of plagioclase dissolution in acid solution at 25°C

Oxburgh, Rachel; Drever, James I.; Sun, Yan-Ting

doi:10.1016/0016-7037(94)90496-0

Cited by 110 publications

(60 citation statements)

References 21 publications

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“…However, diagenetic reactions may be observed in the longer term or at slightly elevated pressure and temperature conditions [e.g., see Hangx and Spiers, 2009;Karner and Schreiber, 1993;Tenthorey and Fitz Gerald, 2006] For a typical reservoir injected with CO 2 (T = 50-100°C, pH 3-5), containing ∼5% plagioclase feldspar and 15% porosity, literature data [Oelkers and Schott, 1995;Oxburgh et al, 1994] imply that dissolutioncontrolled reaction of plagioclase feldspar will take ∼100-1000 years. Transformation of plagioclase within sandstone to form calcite and kaolinite will result in a solid volume increase of 35%, relative to the initial plagioclase volume.…”

Section: Discussionmentioning

confidence: 99%

“…As outlined in Appendix A, under the experimental conditions employed (T = 20-100°C, s eff = 36 MPa, d = 25-275 mm), dissolution and pressure solution mechanisms would result in an expected strain rate of <10 −9 s −1 , according to the dissolution kinetics data of Oxburgh et al [1994] and the pressure solution model of Spiers et al [2004]. Such rates are more than an order of magnitude slower than the slowest creep strain rates observed in the experiments, so that dissolution and/or pressure solution processes are unlikely to have been significant compaction creep mechanisms.…”

Section: Mechanisms Of Compaction Creep In Wet Feldspar Experiments Wmentioning

confidence: 99%

“…[83] Now using equation (A3) together with dissolution rate data (k s ) for quartz and feldspar at pH 3-11 and at 20°C and 80°C (see Table A1) [Brady and Walther, 1990;Oelkers and Schott, 1995;Oxburgh et al, 1994], we can calculate strain rates generated by dissolution-controlled pressure solution under our experimental conditions. For quartz (d = 425 mm, s e = 37 MPa, 8 = 36.9%), strain rates induced by dissolution-controlled pressure solution are predicted to be on the order of 10 −12 to 10 −14 s −1 , while those for feldspar (d = 120 mm, s e = 36 MPa, 8 = 31.6%) are predicted to be on the order of 10 −9 to 10 −11 s −1 .…”

Section: Appendix Amentioning

confidence: 99%

“…Quartz dissolution rate data are from Brady and Walther [1990], and the molar volume of quartz is taken to be 2.3 × 10 −5 m 3 /mol. b Dissolution rate data for bytownite are from Oxburgh et al [1994], and the molar volume of feldspar is taken to be 1.0 × 10 −4 m 3 /mol. c The activation energy for feldspar was taken from Oelkers and Schott [1995] and yielded 18.4 kJ/mol.…”

Section: Appendix Amentioning

confidence: 99%

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Creep of simulated reservoir sands and coupled chemical‐mechanical effects of CO₂ injection

2010

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[1] Geological storage of CO 2 in clastic reservoirs and aquifers is expected to have a variety of coupled chemical-mechanical effects. To investigate the effects of CO 2 injection on creep phenomena, we performed uniaxial compaction experiments on granular aggregates of quartz and feldspar under both wet and dry control conditions. The experiments were performed in constant stress mode. Grain size, temperature, CO 2 partial pressure, and effective stress were varied in order to determine their individual effect. Pore fluid pH was varied by the injection of CO 2 and by addition of acidic and alkaline additives. Pore fluid salinity was increased by the addition of NaCl. Wet samples showed instantaneous compaction upon load application, followed by time-dependent creep. From the mechanical data and microstructures, the main compaction mechanism was inferred to be chemically enhanced microcracking in both quartz and feldspar, with subcritical crack growth, i.e., stress corrosion cracking, controlling deformation in the creep stage. The injection of CO 2 and the concomitant acidification of the pore fluid inhibited microcracking in both the quartz and feldspar samples in line with known effects of pH on stress corrosion cracking. We infer that the injection of CO 2 into quartz-and plagioclase-bearing sandstones will inhibit grain scale microcracking process and that related geomechanical effects, such as reservoir compaction and surface subsidence, will be negligible compared with the poroelastic response.

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Section: Discussionmentioning

confidence: 99%

Section: Mechanisms Of Compaction Creep In Wet Feldspar Experiments Wmentioning

confidence: 99%

Section: Appendix Amentioning

confidence: 99%

Section: Appendix Amentioning

confidence: 99%

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Creep of simulated reservoir sands and coupled chemical‐mechanical effects of CO₂ injection

2010

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“…This is most often caused by precipitation of secondary minerals or by preferential leaching of more reactive species in the primary mineral. The composition of the fluid coexisting with minerals undergoing dissolution will also affect the nonstoichiometric release of components (Amrhein and Suarez, 1988;Casey et al, 1988;Nesbitt and Muir, 1988;Hellmann et al, 1989Hellmann et al, , 1990Inskeep et al, 1991;Nesbitt et al, 1991;Amrhein and Suarez, 1992;Alekseyev et al, 1993;Casey et al, 1993;Oxburgh et al, 1994;Stillings and Brantley, 1995;Gout et al, 1997;. The relatively acidic conditions (low aNa + /aH + ) that characterized the starting fluid for the experiments, for example, initiated albite dissolution in the boehmite field of stability.…”

Section: Article In Pressmentioning

confidence: 99%

A Novel Approach to Experimental Studies of Mineral Dissolution Kinetics

Chen¹

2008

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Currently, DOE is conducting pilot CO 2 injection tests to evaluate the concept of geological sequestration. The injected CO 2 is expected to react with the host rocks and these reactions can potentially alter the porosity, permeability, and mechanical properties of the host or cap rocks. Reactions can also result in precipitation of carbonate-containing minerals that favorably and permanently trap CO 2 underground. Many numerical models have been used to predict these reactions for the carbon sequestration program. However, a firm experimental basis for predicting silicate reaction kinetics in CO 2 injected geological formations is urgently needed to assure the reliability of the geochemical models used for the assessments of carbon sequestration strategies. The funded experimental and theoretical study attempts to resolve this outstanding scientific issue by novel experimental design and theoretical interpretation of silicate dissolution rates at conditions pertinent to geological carbon sequestration.In this four year research grant (three years plus a one year no cost extension), seven (7) laboratory experiments of CO 2 -rock-water interactions were carried out. An experimental design allowed the collection of water samples during experiments in situ and thus prevented back reactions. Analysis of the in situ samples delineated the temporal evolution of aqueous chemistry because of CO 2 -rock-water interactions. The solid products of the experiments were retrieved at the end of the experimental run, and analyzed with a suite of advanced analytical and electron microscopic techniques (i.e., atomic resolution transmission electron microscopy (TEM), scanning electron microscopy (SEM), electron microprobe, X-ray diffraction, X-ray photoelectron spectroscopy (XPS)). As a result, the research project probably has produced one of the best data sets for CO 2 -rock-water interactions in terms of both aqueous solution chemistry and solid characterization. Three experiments were performed using the Navajo sandstone. Navajo sandstone is geologically equivalent to the Nugget sandstone, which is a target formation for a regional partnership injection project. Our experiments provided the experimental data on the potential CO 2 -rock-water interactions that are likely to occur in the aquifer. Geochemical modeling was performed to interpret the experimental results.Our single mineral (feldspar) experiments addressed a basic research need. i.e., the coupled nature of dissolution and precipitation reactions, which has universal implication to the reaction kinetics as it applied to CO 2 sequestration. Our whole rock experiments (Navajo sandstone) addressed the applied research component, e.g., reacting Navajo sandstone with brine and CO 2 has direct relevance on the activities of a number of regional partnerships.The following are the major findings from this project:1. The project generated a large amount of experimental data that is central to evaluating CO 2 -water-rcok interactions and providing ground truth to pred...

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Plagioclase weathering in the groundwater system of a sandy, silicate aquifer

Kim

2002

Hydrological Processes

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Abstract:The weathering rate of plagioclase was estimated in the groundwater system of a sandy, silicate aquifer formed after the Wisconsin Glacial Stage. The study area is an isthmus lying between Crystal and Big Muskellunge Lakes in northern Wisconsin, USA. Plagioclase occupies 3% of the quartz and K-feldspar dominated sediments. Groundwater in the study area is recharged in part by precipitation through the isthmus soils and in part by seepage from Crystal Lake, which is of low ionic strength and chemically in steady state. Water analysis revealed that the chemistry of groundwater recharged from Crystal Lake is regulated by mineral dissolution reactions. The rate constant for plagioclase was estimated using mass balances for sodium concentrations along a groundwater flowline from Crystal Lake. For this calculation, various kinds of hydrological/mineralogical information were used: groundwater flow path from oxygen isotope analysis, groundwater travel times from flow modelling, mineral composition from microprobe analysis and surface area of minerals from BET (Brunauer-Emmett-Teller) analysis. The overall range of the estimation was less than an order of magnitude (3Ð5 ð 10 16 to 3Ð4 ð 10 15 mol/m 2 /s). The result is up to three orders of magnitude slower than the previous field estimates, which applied geometric methods in measuring mineral surface areas. However, this result is somewhat higher than the estimates reported by other BET area-based studies, which were undertaken on soil profiles having different hydrological conditions. This rate difference is interpreted as a result of higher mineral reactivity owing to younger sediment age. The rate difference is smaller when this result is compared with the estimates from the soils of similar age, indicating that the differences in hydrological condition are not sufficient to explain the weathering rate discrepancy between the laboratory and field studies, which is up to five orders of magnitude.

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Mechanism of plagioclase dissolution in acid solution at 25°C

Cited by 110 publications

References 21 publications

Creep of simulated reservoir sands and coupled chemical‐mechanical effects of CO₂ injection

Creep of simulated reservoir sands and coupled chemical‐mechanical effects of CO₂ injection

A Novel Approach to Experimental Studies of Mineral Dissolution Kinetics

Plagioclase weathering in the groundwater system of a sandy, silicate aquifer

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Mechanism of plagioclase dissolution in acid solution at 25°C

Cited by 110 publications

References 21 publications

Creep of simulated reservoir sands and coupled chemical‐mechanical effects of CO2 injection

Creep of simulated reservoir sands and coupled chemical‐mechanical effects of CO2 injection

A Novel Approach to Experimental Studies of Mineral Dissolution Kinetics

Plagioclase weathering in the groundwater system of a sandy, silicate aquifer

Contact Info

Product

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About

Creep of simulated reservoir sands and coupled chemical‐mechanical effects of CO₂ injection

Creep of simulated reservoir sands and coupled chemical‐mechanical effects of CO₂ injection