{"title":"CH4-CO2-H2O-NaCl 四元系统的 SAFT2 状态方程及其在枯竭气藏二氧化碳封存中的应用","authors":"","doi":"10.1016/j.chemgeo.2024.122328","DOIUrl":null,"url":null,"abstract":"<div><p>Understanding the phase equilibria and physical-chemical characteristics of the CH<sub>4</sub>–CO<sub>2</sub>–H<sub>2</sub>O–NaCl quaternary system is important for evaluating costs and risks for the storage of CO<sub>2</sub> in depleted natural gas reservoirs as well as fluid inclusion studies. In this study, phase equilibria and thermodynamic properties of this system were investigated through the utilization of a statistical association fluid theory-based (SAFT) equation of state (EOS) at temperatures from 298 to 513 K (25–240 °C), pressures up to 600 bar (60 MPa) and concentration of NaCl up to 6 mol/kgH<sub>2</sub>O. The model parameters were obtained from the fitting of available experimental data of subsystems (i.e., CH<sub>4</sub>–H<sub>2</sub>O, CH<sub>4</sub>–CO<sub>2</sub>, and CH<sub>4</sub>–H<sub>2</sub>O–NaCl) that were judged to be reliable and incorporation of available parameters for the subsystems (i.e., pure component, CO<sub>2</sub>–H<sub>2</sub>O, and CO<sub>2</sub>–H<sub>2</sub>O–NaCl). Using the SAFT EOS developed in this study, we predicted the solubility of (CH<sub>4</sub> + CO<sub>2</sub>) gas mixtures in pure H<sub>2</sub>O and compared it with the available experimental data and the predicted values from four popular numerical simulators. The results indicate that our model can provide reliable predictions for the CH<sub>4</sub>–CO<sub>2</sub>–H<sub>2</sub>O ternary system. Subsequently, we further predicted the phase equilibria and density of the CH<sub>4</sub>–CO<sub>2</sub>–H<sub>2</sub>O–NaCl system with NaCl varying from 0 to 6 mol/kgH<sub>2</sub>O. We also employed the SAFT EOS to predict the solubility of CO<sub>2</sub> and CH<sub>4</sub> in the water-alternating-gas process for CO<sub>2</sub>-enhanced oil recovery, demonstrating good agreement with the simulation results obtained through the Peng-Robinson EOS for predicting the CO<sub>2</sub> and CH<sub>4</sub> solubility. These predicted thermodynamic properties and phase behaviors in the CH<sub>4</sub>–CO<sub>2</sub>–H<sub>2</sub>O–NaCl system provide quantitative insights into the implications of CO<sub>2</sub> storage in depleted oil and gas reservoirs.</p></div>","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":null,"pages":null},"PeriodicalIF":3.6000,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S000925412400408X/pdfft?md5=ae02dd4fe6421eedf31fc9a79aff1f72&pid=1-s2.0-S000925412400408X-main.pdf","citationCount":"0","resultStr":"{\"title\":\"SAFT2 equation of state for the CH4–CO2–H2O–NaCl quaternary system with applications to CO2 storage in depleted gas reservoirs\",\"authors\":\"\",\"doi\":\"10.1016/j.chemgeo.2024.122328\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Understanding the phase equilibria and physical-chemical characteristics of the CH<sub>4</sub>–CO<sub>2</sub>–H<sub>2</sub>O–NaCl quaternary system is important for evaluating costs and risks for the storage of CO<sub>2</sub> in depleted natural gas reservoirs as well as fluid inclusion studies. In this study, phase equilibria and thermodynamic properties of this system were investigated through the utilization of a statistical association fluid theory-based (SAFT) equation of state (EOS) at temperatures from 298 to 513 K (25–240 °C), pressures up to 600 bar (60 MPa) and concentration of NaCl up to 6 mol/kgH<sub>2</sub>O. The model parameters were obtained from the fitting of available experimental data of subsystems (i.e., CH<sub>4</sub>–H<sub>2</sub>O, CH<sub>4</sub>–CO<sub>2</sub>, and CH<sub>4</sub>–H<sub>2</sub>O–NaCl) that were judged to be reliable and incorporation of available parameters for the subsystems (i.e., pure component, CO<sub>2</sub>–H<sub>2</sub>O, and CO<sub>2</sub>–H<sub>2</sub>O–NaCl). Using the SAFT EOS developed in this study, we predicted the solubility of (CH<sub>4</sub> + CO<sub>2</sub>) gas mixtures in pure H<sub>2</sub>O and compared it with the available experimental data and the predicted values from four popular numerical simulators. The results indicate that our model can provide reliable predictions for the CH<sub>4</sub>–CO<sub>2</sub>–H<sub>2</sub>O ternary system. Subsequently, we further predicted the phase equilibria and density of the CH<sub>4</sub>–CO<sub>2</sub>–H<sub>2</sub>O–NaCl system with NaCl varying from 0 to 6 mol/kgH<sub>2</sub>O. We also employed the SAFT EOS to predict the solubility of CO<sub>2</sub> and CH<sub>4</sub> in the water-alternating-gas process for CO<sub>2</sub>-enhanced oil recovery, demonstrating good agreement with the simulation results obtained through the Peng-Robinson EOS for predicting the CO<sub>2</sub> and CH<sub>4</sub> solubility. These predicted thermodynamic properties and phase behaviors in the CH<sub>4</sub>–CO<sub>2</sub>–H<sub>2</sub>O–NaCl system provide quantitative insights into the implications of CO<sub>2</sub> storage in depleted oil and gas reservoirs.</p></div>\",\"PeriodicalId\":9847,\"journal\":{\"name\":\"Chemical Geology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.6000,\"publicationDate\":\"2024-08-12\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S000925412400408X/pdfft?md5=ae02dd4fe6421eedf31fc9a79aff1f72&pid=1-s2.0-S000925412400408X-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Chemical Geology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S000925412400408X\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Geology","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S000925412400408X","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
SAFT2 equation of state for the CH4–CO2–H2O–NaCl quaternary system with applications to CO2 storage in depleted gas reservoirs
Understanding the phase equilibria and physical-chemical characteristics of the CH4–CO2–H2O–NaCl quaternary system is important for evaluating costs and risks for the storage of CO2 in depleted natural gas reservoirs as well as fluid inclusion studies. In this study, phase equilibria and thermodynamic properties of this system were investigated through the utilization of a statistical association fluid theory-based (SAFT) equation of state (EOS) at temperatures from 298 to 513 K (25–240 °C), pressures up to 600 bar (60 MPa) and concentration of NaCl up to 6 mol/kgH2O. The model parameters were obtained from the fitting of available experimental data of subsystems (i.e., CH4–H2O, CH4–CO2, and CH4–H2O–NaCl) that were judged to be reliable and incorporation of available parameters for the subsystems (i.e., pure component, CO2–H2O, and CO2–H2O–NaCl). Using the SAFT EOS developed in this study, we predicted the solubility of (CH4 + CO2) gas mixtures in pure H2O and compared it with the available experimental data and the predicted values from four popular numerical simulators. The results indicate that our model can provide reliable predictions for the CH4–CO2–H2O ternary system. Subsequently, we further predicted the phase equilibria and density of the CH4–CO2–H2O–NaCl system with NaCl varying from 0 to 6 mol/kgH2O. We also employed the SAFT EOS to predict the solubility of CO2 and CH4 in the water-alternating-gas process for CO2-enhanced oil recovery, demonstrating good agreement with the simulation results obtained through the Peng-Robinson EOS for predicting the CO2 and CH4 solubility. These predicted thermodynamic properties and phase behaviors in the CH4–CO2–H2O–NaCl system provide quantitative insights into the implications of CO2 storage in depleted oil and gas reservoirs.
期刊介绍:
Chemical Geology is an international journal that publishes original research papers on isotopic and elemental geochemistry, geochronology and cosmochemistry.
The Journal focuses on chemical processes in igneous, metamorphic, and sedimentary petrology, low- and high-temperature aqueous solutions, biogeochemistry, the environment and cosmochemistry.
Papers that are field, experimentally, or computationally based are appropriate if they are of broad international interest. The Journal generally does not publish papers that are primarily of regional or local interest, or which are primarily focused on remediation and applied geochemistry.
The Journal also welcomes innovative papers dealing with significant analytical advances that are of wide interest in the community and extend significantly beyond the scope of what would be included in the methods section of a standard research paper.