The pore solution phase of carbonated cement pastes

Anstice, D.J.; Page, Christopher; Page, M.M.

doi:10.1016/j.cemconres.2004.06.041

Cited by 162 publications

(92 citation statements)

References 8 publications

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“…Moreover, once the calcium hydroxide is depleted, these ions can compete with the hydrated calcium silicates (tobermorites) (27), thereby altering the structure of the slurry, as established by other authors (28).…”

Section: Discussionmentioning

confidence: 99%

“…La interacción del ión magnesio con los componentes de la pasta de cemento implica una serie de procesos que suponen fundamentalmente la precipitación de brucita (MH) sobre la pasta (25) En aquellos ensayos con presencia de CO 2 como único gas agrio, los valores de pH y concentración de calcio indican que el ataque de los iones carbonato y bicarbonato se produce preferentemente sobre la portlandita, observándose por DRX la generación de calcita y/o aragonito, hecho reportado anteriormente en escasos trabajos (26). Asimismo, una vez agotado el hidróxido de calcio, los referidos iones podrían competir con los silicatos de calcio del gel hidratado del cemento (27), siendo la estructura del cemento alterada, tal y como se ha establecido por otros autores (28).…”

Section: Discussionunclassified

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Ataque del anhídrido carbónico y el ácido sulfhídrico sobre pastas de cemento API clase H expuestas a aguas de formación salinas

Márquez¹,

Sánchez²,

Martín-del-Río³

et al. 2010

Mater. construcc.

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RESUMENSe simuló la acción agresiva de los denominados iones fundamentales (sulfato, cloruro y magnesio) y los gases agrios presentes en el gas natural (CO 2 y H 2 S) sobre un cemento API clase H utilizado en pozos gasíferos a presión y temperatura elevadas, al objeto de observar sus alteraciones fisicoquímicas por la acción combinada de tales gases y las aguas de formación. Se prepararon varias probetas del material cementante para su inmersión en disoluciones neutras, conteniendo los iones fundamentales en concentraciones fijas, dentro de reactores tipo Parr. Se analizaron durante más de dos meses una serie de disoluciones en contacto con el cemento utilizado; así como, mediante DRX, la evolución de la mineralogía de dicho material entre los 14 y los 60 días. Los principales efectos de ambos gases, en conjunto o por separado, sobre la durabilidad del cemento fueron, respectivamente, la formación de carbonato cálcico y la lixiviación de algunos componentes.Palabras clave: cementos para pozos de petróleo, durabilidad, pasta de cemento, difracción de rayos X, fases cristalinas. SUMMARYThis paper discusses the attack of the major ions (sulfate, chloride, and magnesium) and sour gases, present in natural gas (CO 2 y SH 2 ), on API class H cement, the type used in gas wells under high pressure and temperature. The effects of these chemical agents on this cement was simulated to study the physicochemical changes due to the action of sour gases and formation water. Cement specimens were immersed in neutral solutions containing fixed concentrations of the major ions inside Parr reactors. These solutions were analysed and XRD analyses were conducted for over two months to identify mineralogical variations from 14 to 60 days. The objective of this research was to determine the effects of the joint attack of major ions and sour gases on cement pastes. The main effects of both gases, jointly or separately, on cement durability were, respectively, the carbonation process and the leaching of some components.Keywords: petroleum wells cemen, durability, cement slurries, XRD , crystalline phases. INTRODUCCIÓNLos denominados gases agrios, anhídrido carbónico y ácido sulfhídrico, significativamente presentes en la mayoría de yacimientos de gas y petróleo (1), pueden provocar importantes cambios fisicoquímicos sobre el cemento colocado entre el revestidor de un pozo y las formaciones rocosas (2); dicho material cementante se deteriora con el tiempo al ser atacado por ambos gases, sobre todo en presencia de ciertos iones (sulfato, cloruro o magnesio) contenidos en concentraciones que superan los 40.000 ppm en las aguas de formación en contacto con el cemento (3). Las concentraciones del ácido sulfhídrico y anhídrido carbónico en el gas natural suelen arrojar valores no superiores al 10% y 30% molar, respectivamente (4). Los gases agrios se disuelven en medio acuoso produciendo una serie de iones (sulfuro, carbonato, etc.) que afectan significativamente a la durabilidad del cemento en los pozos de gas y petróleo, influyendo sobre l...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionunclassified

Ataque del anhídrido carbónico y el ácido sulfhídrico sobre pastas de cemento API clase H expuestas a aguas de formación salinas

Márquez¹,

Sánchez²,

Martín-del-Río³

et al. 2010

Mater. construcc.

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“…(2) Influences of other ions and pH on potentiometric response to chloride: Ions such as Ca 4 2− may exist in concrete in different concentrations depending on the raw materials used and service environments such as marine, de-icing salts and sulfate attack [26]. For the fully carbonated concretes, the pH value of the pore solution decreases to as low as 7.5 [27].…”

Section: Measurement Methodsmentioning

confidence: 99%

“…For the fully carbonated concretes, the pH value of the pore solution decreases to as low as 7.5 [27]. Therefore, four series solutions were prepared: distilled water (O), saturated Ca(OH) 2 solution (A), synthetic concrete pore solution (B) and synthetic concrete pore solution plus 0.1 M concentration of SO 4 2− (C), and then 0.1 M and 1.0 M concentrations of chloride ions were added using NaCl, KCl and CaCl 2 respectively. Potential readings of the sensor in these solutions were tested.…”

Section: Measurement Methodsmentioning

confidence: 99%

“…Therefore, monitoring of free chloride content is one of the most important methods to prevent and control premature deterioration of concretes in chloride environments. Two types of methods have been used for such a purpose: the leaching method [3], based on the interaction of concrete with water and analysis of the leachate; the pore-pressing technique [4], based on the application of high pressure to a sample of the concrete or mortar allowing extraction of a small portion of liquid that can be analyzed. These two procedures, although well-established, are both destructive and time-consuming, and require periodical sampling from the structure of concern.…”

Section: Introductionmentioning

confidence: 99%

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Fabrication and Performance of All-Solid-State Chloride Sensors in Synthetic Concrete Pore Solutions

Gao

Zhang

Yang

et al. 2010

Sensors

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Abstract:One type of all-solid-state chloride sensor was fabricated using a MnO 2 electrode and a Ag/AgCl electrode. The potentiometric response of the sensor to chloride in synthetic concrete pore solutions was systematically studied, and the polarization performance was also evaluated. The results show a good linear relationship between the potential reading of the sensor and the logarithm of chloride activity (concentration ranges from 0.05 to 5.0 M), and the potential value remains stable with increasing immersion time. ions have little influence on the potentiometric response of the sensor to chloride, but the pH has a significant influence on the potential value of the sensor at low chloride concentration. The potential reading of the sensor increases linearly with the solution temperature over the range from 5 to 45 C. Meanwhile, an excellent polarization behavior is proven by galvanostatic and potentiodynamic tests. All of the results reveal that the developed sensor has a great potential for monitoring chloride ions in concrete environments.

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