SPE Projects, Facilities & Construction
Volume 6, Number 4, December 2011, pp. 158-165

SPE-132403-PA

Estimation of Potential Precipitation From an Equilibrated Calcium Carbonate Aqueous Phase Using Simple Predictive Tool

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DOI  More information 10.2118/132403-PA http://dx.doi.org/10.2118/132403-PA

Citation

  • Bahadori, A. 2011. Estimation of Potential Precipitation From an Equilibrated Calcium Carbonate Aqueous Phase Using Simple Predictive Tool. SPE Proj Fac & Const  6 (4): 158-165. SPE-132403-PA. http://dx.doi.org/10.2118/132403-PA.

Discipline Categories

  • 4.6.4 Scale

Keywords

  • Calcium carbonate, Scale, Saturation index, CO2 Sequestration, Carbon dioxide

Summary

Carbon dioxide (CO2) sequestration in saline aquifers has been proposed as one of the most practical options for reducing CO2 emissions into the atmosphere. Massive CO2 injection into an aquifer would alter the geochemical equilibrium between the rock-forming minerals and the formation water. In this work, a novel and simple predictive tool is presented to estimate the formation of calcium carbonate (CaCO3) scaling as a function of pH, temperature, ionic strength of the solution, calcium cation concentration, bicarbonate anion concentration, and CO2 mole fraction when the water mixture is saturated with a gas containing CO2 to evaluate the effect of solution conditions on the tendency and extent of precipitation. The proposed simple method covers concentrations of calcium cation or bicarbonate anion in the range of 10 to 10 000 mg/L, with temperature ranging between 5 and 90°C, total ionic strength ranging between 0.1 and 3.6, and pH values ranging between 5.5 and 8. The predicted values are found to be in good agreement with the reported data, with average absolute deviations being less than 2.6%. The proposed tool is superior because of its accuracy and clear numerical background based on the Vandermonde matrix, wherein the relevant coefficients can be retuned quickly if more data become available in the future. The simple predictive tool proposed in the paper can be of immense practical value for engineers and researchers to have a quick check on the formation of calcium carbonate scaling when the water mixture is saturated with a gas containing CO2 at various conditions without opting for any experimental measurements. In particular, process engineers would find the proposed method to be user friendly, involving no complex expressions and presenting transparent calculations.

© 2011. Society of Petroleum Engineers

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History

  • Original manuscript received: 6 August 2010
  • Meeting paper published: 6 June 2010
  • Revised manuscript received: 5 January 2011
  • Manuscript approved: 4 April 2011
  • Published online: 10 November 2011
  • Version of record: 16 December 2011