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Measurement and Modeling of Fluid-Fluid Miscibility in Multicomponent Hydrocarbon Systems Subhash C

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Measurement and Modeling of Fluid-Fluid Miscibility in Multicomponent Hydrocarbon Systems Subhash C Louisiana State University LSU Digital Commons LSU Doctoral Dissertations Graduate School 2005 Measurement and modeling of fluid-fluid miscibility in multicomponent hydrocarbon systems Subhash C. Ayirala Louisiana State University and Agricultural and Mechanical College, [email protected] Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_dissertations Part of the Petroleum Engineering Commons Recommended Citation Ayirala, Subhash C., "Measurement and modeling of fluid-fluid miscibility in multicomponent hydrocarbon systems" (2005). LSU Doctoral Dissertations. 943. https://digitalcommons.lsu.edu/gradschool_dissertations/943 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Doctoral Dissertations by an authorized graduate school editor of LSU Digital Commons. For more information, please [email protected]. MEASUREMENT AND MODELING OF FLUID-FLUID MISCIBILITY IN MULTICOMPONENT HYDROCARBON SYSTEMS A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the Requirements for the degree of Doctor of Philosophy in The Department of Petroleum Engineering by Subhash C. Ayirala B.Tech in Chemical Engineering, Sri Venkateswara Univeristy, Tirupati, India, 1996 M.Tech in Chemical Engineering, Indian Institute of Technology, Kharagpur, India, 1998 M.S. in Petroleum Engineering, Louisiana State University, 2002 August 2005 DEDICATION This work is dedicated to my wife, Kruthi; my parents; my brother, Dhanuj and my beloved sisters, Hema, Suma and Siri. ii ACKNOWLEDGEMENTS I am deeply indebted to my mentor and advisor Dr. Dandina N. Rao for his able guidance, motivation and moral support throughout this work. It is very fortunate to work with Dr. Rao on an exciting project in Enhanced Oil Recovery. I am thankful to Dr. Anuj Gupta, Dr. Karsten E. Thompson, Dr. Edward B. Overton and Dr. Donald Dean Adrian for serving as members on the examination committee. I am also thankful to Dr. Brij B. Maini, professor, University of Calgary for his valuable suggestions and comments given to improve the quality of this dissertation. The financial support of this project by the U.S Department of Energy under Award No. DE-FC26-02NT-15323 is greatly appreciated. I express my sincere thanks to Dr. Jerry Casteel of NPTO/DOE for his support and encouragement. I also thank Dr. Jong Lee of Petro-Canada and Dr. David Fong and Dr. Frank McIntyre of Husky Oil for helpful technical discussions. I would like to express my sincere thanks to my friends Madhav Kulkarni, Daryl Sequiera and Wei Xu for providing technical help during this project whenever needed. I am also greatly indebted to all the faculty members, staff and graduate students in the Petroleum Engineering Department for their help and friendship offered during my stay at LSU. Finally I express my profound gratitude to my wife, parents, brother and sisters, who always served as the source of inspiration to finish this project. iii TABLE OF CONTENTS DEDICATION………………………………………………………………………………………ii ACKNOWLEDGEMENTS………………………………………………………………………. iii LIST OF TABLES…………………………………………………………………………………..vii LIST OF FIGURES………………………………………………………………………………... x ABSTRACT……………………………………………………………………………………….. xiv 1. INTRODUCTION…………………………………………….………….….……...……….… 1 1.1 Problem Statement………………….…………………………….………….….…………. 1 1.2 Objectives.………………………………..….....…………………..………………………. 4 1.3 Methodology………………………..……….………....…………………………………… 5 2. LITERATURE REVIEW………………………………………….………….……...…….…. 8 2.1. Current EOR Scenario in United States…………….…………….….……….……………. 8 2.2. Definition of Fluid-Fluid Miscibility…………..………………………………………………… 9 2.3. Need for Fluid-Fluid Miscibility in Gas Injection EOR………….…………………..……. 10 2.4. Experimental Techniques to Determine Gas-Oil Miscibility…………..………….………. 11 2.4.1. Slim-Tube Displacement Test………………………..…………………….…..…… 12 2.4.2. Rising Bubble Apparatus…………………………………….……………...……… 14 2.4.3. Pressure Composition (P-X) Diagrams…………………………..………………….. 14 2.4.4. The New Vanishing Interfacial Tension (VIT) Technique…………………….…… 15 2.5. Mass Transfer Effects in Gas-Oil Miscibility Development………………………….…… 16 2.6. Computational Models to Determine Gas-Oil Miscibility……………………….…………. 17 2.6.1. EOS Models……………………………………………………….……………..….. 18 2.6.2. Analytical Models…………………………………….………………..………....… 20 2.7. Interfacial Tension……………………………………………………………………..…... 22 2.7.1. Role of Interfacial Tension in Fluid-Fluid Phase Equilibria………………………… 22 2.7.2. IFT Measurement Techniques………………………………………….……..……. 25 2.7.2.1. Capillary Rise Technique………………………………………………….… 26 2.7.2.2. Drop Weight Method………………………………………………………… 28 2.7.2.3. Ring Method…………………………………………………………………. 29 2.7.2.4. Wilhelmy Plate Apparatus……………………………………………….….. 30 2.7.2.5. Pendent Drop Method…………………………………………………….…. 31 2.7.2.6. Sessile Drop Method………………………………………………………… 34 2.7.2.7. Spinning Drop Method…………………………………………………..….. 35 2.7.3. IFT Predictive Models……………………………………………………………….. 36 2.7.3.1. Parachor Model………………………………………………………………. 36 2.7.3.2. Corresponding States Theory……………………………………………….. 43 2.7.3.3. Thermodynamic Correlations…………………………………………….….. 45 2.7.3.4. Gradient Theory……………………………………………………………... 47 3. EXPERIMENTAL APPARATUS AND PROCEDURES……………………………………. iv 3. EXPERIMENTAL APPARATUS AND PROCEDURES……………………………………. 52 3.1. Standard Ternary Liquid System……………………………………………….……..…… 53 3.1.1. Reagents………………………………………………………………..……….…… 53 3.1.2. Experimental Setup and Procedure………………………………………………….. 53 3.2. Standard Gas-Oil Systems……………………………………………………..…………… 58 3.2.1. Reagents……………………………………………………………..……………… 58 3.2.2. Experimental Setup and Procedure………………………………………………….. 58 4. RESULTS AND DISCUSSION………………………………………………………………… 63 4.1. IFT Measurements in a Standard Ternary Liquid System…………………….…………… 64 4.1.1. Solubility and Miscibility…………………………………………………..……….. 64 4.1.2. Solvent-Oil Ratio Effects on IFT……………………………………………………. 66 4.1.3. IFT Measurements Using Capillary Rise Technique…………………………….….. 72 4.1.4. Correlation of Solubility and Miscibility with IFT…………………………………. 75 4.1.5. Determination of VIT Miscibility……………………………………………..……. 77 4.2. IFT Measurements in Standard Gas-Oil Systems……………………………………….…. 78 4.2.1. Bubble Point Pressure Estimation of Synthetic Live Oil……………………………. 78 4.2.2. Density Meter Calibration and Density Measurements of Pure Fluids……………… 79 o 4.2.3. IFT Measurements in n-Decane-CO2 System at 100 F………………………….…. 82 o 4.2.4. IFT Measurements in Synthetic Live Oil-CO2 System at 160 F…………………... 86 4.2.5. Effect of Gas-Oil Ratio on Dynamic Interfacial Tension………………………..…. 90 4.3. Comparison of VIT Experiments of RKR and Terra Nova Reservoir Fluids with EOS Model Computations……………………………………….……………………..….……. 94 4.3.1 EOS Tuning………………………………………………………………………..… 94 4.3.2 Gas-Oil Miscibility Determination Using EOS Model………………………….…. 98 4.3.3 Reality Check………………………………………………………………………. 106 4.4 Application of Parachor IFT Model to Predict Fluid-Fluid Miscibility………………..….. 109 4.4.1 Gas-Oil IFT Calculations……………………………………………………………109 4.4.2 Gas-Oil Miscibility Calculations……………………………………………..……. 112 4.4.3 Mass Transfer Effects on Fluid-Fluid Miscibility………………………………… 114 4.5 Newly Proposed Mechanistic Parachor Model for Prediction of Dynamic IFT and Miscibility in Multicomponent Hydrocarbon Systems…………………………………..… 115 4.5.1 Background on Development of Proposed Mechanistic Parachor Model…………. 116 4.5.2 Application of the Proposed Mechanistic Model to Crude Oil-Gas Systems……… 120 4.5.3 Application of the Proposed Mechanistic Model to Crude Oil Systems………..…. 136 4.5.4 Sensitivity Studies on Proposed Mechanistic Parachor Model…………………..… 140 4.5.5 Generalized Regression Models for Mechanistic Model Exponent Prediction……. 143 4.5.6 Validation of the Generalized Regression Models for Mechanistic Model Exponent Prediction…………………………………………………………….……147 4.5.7 Prediction of Dynamic Gas-Oil Miscibility Using the Mechanistic Model………... 150 4.6 Modeling of Dynamic Gas-Oil Interfacial Tension and Miscibility in Standard Gas-Oil Systems at Elevated Pressures and Temperatures……………….………………………… 152 o 4.6.1 n-Decane-CO2 System at 100 F…………………………………………………….152 o 4.6.2 Synthetic Live Oil-CO2 System at 160 F……………………………….………… 154 4.7 Relationship between Developed Miscibility in Gas Injection EOR Projects and Laboratory Gas-Oil Interfacial Tension Measurements…………………….…….………….159 v 5. CONCLUSIONS AND RECOMMENDATIONS……………………….…………………… 168 5.1. Summary of Conclusions……………………………………………………….……………168 5.2. Recommendations for Future Work…………………………………………...……………. 176 REFERENCES CITED…………….…………………………..………………...……………….. 178 VITA……………………………………………………………………………………………….. 190 vi LIST OF TABLES 1. Optimum Weight Factors for Proper EOS Tuning……………….………………………………….. 19 2. Effect of Pressure on Parachors of Crude Cuts………………….…………………….…………….. 42 3. Summary of Parachor Characteristics………………………………………….……....……………. 43 4. Solubility of Benzene in Water at Various Ethanol Enrichments………………………….……….. 65 5. Measured Benzene Interfacial Tensions in Non-Equilibrated Aqueous Ethanol at Various Ethanol Enrichments and Feed Compositions…………………….……………………………………….…. 67 6. Measured Benzene IFT’s in Pre-Equilibrated Aqueous Ethanol at 30% and 40% Ethanol Enrichments and Various Feed Compositions…………………………………….………………… 71 7. Benzene IFT’s in Pre-Equilibrated Aqueous Ethanol at Ethanol Enrichments Above 40%………… 73 8. Measured Equilibrium
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