Modeling the Thermodynamic Properties of Common Minerals at High Temperature, Pressure and Salinity with Complex Ions
- 30 May 2012
- conference paper
- conference paper
- Published by Society of Petroleum Engineers (SPE) in All Days
Abstract
The ultra-high temperature (150–250°C), pressure (1,000–2,000 bar, 15,000 to 30,000 psi) and TDS (>300,000 mg/L) in deepwater oil and gas production pose significant challenges to scaling control due to limited knowledge of mineral solubility, kinetics and inhibitor efficiency at these extreme conditions. Prediction of thermodynamic properties of common minerals is currently limited by lack of experimental data and inadequate understanding of modeling parameters. In this study, a new apparatus was built to test scale formation and inhibition at high temperatures and pressures. Solubilities of two common minerals, barite and calcite, were tested at temperature up to 250°C, pressure up to 1,500 bar (22,000 psi) and ionic strength up to 6m in solutions with elevated concentrations of mixed electrolytes (e.g., calcium, magnesium, sulfate and carbonate) representing the maximum range of interferences expected (95%CI) in oil and gas wells. As an attempt towards experimentally determining mineral solubility at high temperature, pressure and salinity, not only does this study contribute to the extremely limited data base, but it also provides a reliable approach for evaluating and adjusting model predictions at extreme conditions. Predictions by a thermodynamic model based on Pitzer's ion interaction theory were evaluated using experimental data. The dependence of Pitzer's coefficients for ion activity coefficients on temperature and pressure was examined and incorporated into the scale prediction model, whose prediction is consistent with both experimental and literature data at all conditions tested.Keywords
This publication has 17 references indexed in Scilit:
- Solubility of Barite up to 250 °C and 1500 bar in up to 6 m NaCl SolutionIndustrial & Engineering Chemistry Research, 2012
- Coupled phase and aqueous species equilibrium of the H2O–CO2–NaCl–CaCO3 system from 0 to 250°C, 1 to 1000bar with NaCl concentrations up to saturation of haliteGeochimica et Cosmochimica Acta, 2008
- The speciation equilibrium coupling with phase equilibrium in the H2O–CO2–NaCl system from 0 to 250 °C, from 0 to 1000 bar, and from 0 to 5 molality of NaClChemical Geology, 2007
- A thermodynamic model for the solubility of barite and celestite in electrolyte solutions and seawater to 200°C and to 1 kbarChemical Geology, 1999
- The carbonic acid system and calcite solubility in aqueous Na-K-Ca-Mg-Cl-SO4 solutions from 0 to 90°CGeochimica et Cosmochimica Acta, 1993
- Revised Chemical Equilibrium Data for Major Water—Mineral Reactions and Their LimitationsPublished by American Chemical Society (ACS) ,1990
- The prediction of mineral solubilities in natural waters: A chemical equilibrium model for the Na-K-Ca-Cl-SO4-H2O system to high concentration from 0 to 250°CGeochimica et Cosmochimica Acta, 1989
- The prediction of mineral solubilities in natural waters: The Na-K-Mg-Ca-H-Cl-SO4-OH-HCO3-CO3-CO2-H2O system to high ionic strengths at 25°CGeochimica et Cosmochimica Acta, 1984
- Thermodynamics of electrolytes. 12. Dielectric properties of water and Debye-Hueckel parameters to 350.degree.C and 1 kbarThe Journal of Physical Chemistry, 1979
- Thermodynamics of electrolytes. I. Theoretical basis and general equationsThe Journal of Physical Chemistry, 1973