Unsaturated water movement through paraho retorted oil shale at Anvil Points, Colorado Item Type Thesis-Reproduction (electronic); text Authors Freshley, Mark David. Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 01/10/2021 17:40:16 Link to Item http://hdl.handle.net/10150/191767 UNSATURATED WATER MOVEMENT THROUGH PARAHO RETORTED OIL SHALE AT ANVIL POINTS, COLORADO by Mark David Freshley A Thesis Submitted to the Faculty of the DEPARTMENT OF HYDROLOGY AND WATER RESOURCES In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE WITH A MAJOR IN HYDROLOGY In the Graduate College THE UNIVERSITY OF ARIZONA 1982 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of re- quirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his judg- ment the proposed use of the material is in the interests of scholar- ship. In all other instances, however, permission must be obtained from the author. SIGNED: D. APPROVAL BY THESIS DIRECTOR This thesis has been approved on the date shown below: DANIEL D. EVANS Date-' Professor of Hydrology ACKNOWLEDGMENTS Completion of this thesis would not have been possible without the involvement of many individuals. The encouragement and guidance of Dr. Daniel D. Evans is especially appreciated. Drs. Shlomo P. Neuman and Thomas Maddock III served on my thesis committee, and I thank them for their useful comments and suggestions during review and defense of the manuscript. I wish to thank Dr. Stanley N. Davis for the inval- uable opportunity to serve as a teaching assistant in his hydrogeology class for 11/2 years. The experience taught me how to think on my feet. Support of research conducted for this thesis was provided by Battelle Pacific Northwest Laboratory (PNL). Support and guidance has been given by Dr. R. E. Wildung and Mr. J. M. Zachara of the Ecological Sciences Department. Interaction and discussion with personnel of the Geosciences and Engineering Department has been most useful, notably Mr. Frederick W. Bond, Dr. Glendon W. Gee, Dr. Sumant K. Gupta, Mr. Charles R. Cole, Dr. C. S. Simmons, Mr. Stuart M. Brown, and Mr. A. F. Gasperino. I also wish to thank June Fabryka-Martin for her editorial comments; Anna McKew for typing the final draft; Ann Cotgageorge for her assistance in drafting the figures; and other fellow students and staff at PNL for their friendship. Lastly, I wish to express gratitude to my parents and family for their support and encouragement which made the sometimes trying pursuit of education bearable. TABLE OF CONTENTS Page LIST OF TABLES vi LIST OF ILLUSTRATIONS vii ABSTRACT INTRODUCTION 1 ASPECTS OF OIL-SHALE PROCESSING AND SPENT-SHALE DISPOSAL . • • 7 Geology of Green River Oil Shale 8 Geologic History of the Green River Formation 8 Mineralogy of Green River Oil Shale 9 Mining and Crushing 11 Above-Ground Retorting Processes 12 Paraho Direct-Heating Mode Process 13 Description of Retorted Oil Shale 15 Physical Characteristics 15 Chemical Characteristics 16 Spent-Shale Disposal 20 Description of the Anvil Points Site 24 UNSATURATED-ZONE MODELING 26 State of Water in Unsaturated Soils 26 The Governing Flow Equation 28 Description of Unsaturated Flow Parameters 30 Soil-Moisture Characteristics 30 Unsaturated Hydraulic Conductivity 31 Initial and Boundary Conditions 35 Potential Evapotranspiration 37 Actual Evapotranspiration 40 Estimation of the Sink Term 41 Assumptions for the Flow Model 45 DATA COLLECTION AND ANALYSIS 48 Description of Model Cases 49 Existing Disposal Pile 49 Transient Disposal Pile 49 Revegetated Disposal Pile 51 Model Nodal Structure 51 iv TABLE OF CONTENTS--Continued Page Material Hydraulic Properties 51 Moisture Characteristics 51 Hydraulic Conductivity Relationships 53 Initial Conditions 55 Boundary Conditions 57 Precipitation 58 Potential Evapotranspiration 59 Components of the Sink Term 59 MODELING RESULTS 64 Existing Pile Case 64 Transient Pile Cases 67 Plant Simulation 78 Discussion 78 SENSITIVTY ANALYSIS 85 Theory 85 Calculation of Sensitivity 87 Results 93 Discussion 101 SUMMARY AND CONCLUSIONS 108 Recommendations for Future Research 110 APPENDIX A: MOISTURE FLOW EQUATION IN FINITE DIFFERENCE FORM 113 APPENDIX B: POLYNOMIAL DESCRIPTION OF HYDRAULIC PROPERTIES . 117 APPENDIX C: COMPUTER PROGRAM EXTEND 118 LITERATURE CITED 120 LIST OF TABLES Table Page 1. Particle size analyses of retorted shale, prior to and following compaction 17 2. Chemical analysis of unsieved spent shale 19 3. Chemical analysis of percolate water from a lysimeter at Anvil Points, Colorado 21 4. Comparison of particle-size distributions for the Nihill channery loam and the Gilat loam 52 5. Summary of saturated hydraulic conductivities 55 6. Summary of initial moisture content and saturated porosity for each material used in the transient pile scenario . 57 7. Growing days required for cheatgrass roots to reach various depths 62 8. Annual water balance summary for the existing pile simulation 64 9. Relative sensitivity of annual drainage and surface evapo- ration to parameters not related to simulation of plants . 95 10. Relative sensitivity of annual drainage, surface evaporation and transpiration to parameters used for plant simulation . 96 vi LIST OF ILLUSTRATIONS Figure Page 1. Distribution of oil shale in the Green River formation, Colorado, Utah and Wyoming 2 2. Average chemical composition of Green River oil shale for samples from Rifle, Colorado 10 3. Schematic of the Paraho direct-heating mode retort . 14 4. Cooling rate for Paraho retorted oil shale at 1 m depth measured with a thermocouple probe 18 5. Conceptual design for a typical head-of-canyon spent shale disposal pile 23 6. Examples of moisture characteristic curves for clay, sandy loam and sand 32 7. Examples of hydraulic conductivity curves for clay, sandy loam and sand 33 8. Actual transpiration as a ratio to potential transpiration plotted against available water depletion 42 9. General shape of the dimensionless coefficient a (9) as a function of water content 44 10. Schematic of the existing spent-shale disposal pile . 50 11. Schematic of the transient spent-shale disposal pile . 50 12. Moisture characteristic curves for the Nihill soil and spent shale compacted to 1.2 and 1.5 g/cm3 54 13. Hydraulic conductivity relationships for the Nihill soil and spent shale compacted to 1.2 and 1.5 g/cm3 56 14. Cumulative rainfall for 1979 near Anvil Points, Colorado 60 15. Potential evapotranspiration (PET) for 1979 as calculated by the Penman method 61 16. Hourly distribution of potential evapotranspiration . 61 vii viii LIST OF - ILLUSTRATIONS—Continued Figure Page 17. Distribution of moisture in the upper 150 cm for the existing pile simulation on days 1 and 365 65 18. Water content versus time at depths 5, 15, and 25 cm for the existing pile simulation 66 19. Water content versus time during year 1 at depths 0.2, 0.5, and 6.0 m for the initially dry profile 68 20. Water content versus time during year 1 at depths 0.2, 0.5, and 6.0 m for the initially wet profile 69 21. Distribution of moisture in the initially dry profile on days 1, 90, 180, and 365 of year 1 70 22. Distribution of moisture in the initially wet profile on days 1, 90, 180, and 365 of year 1 71 23. Distribution of moisture in the initially dry profile at the end of years 6, 10, 20, and 30 72 24. Distribution of moisture in the initially wet profile at the end of years 6, 10, 15, and 30 73 25. Cumulative drainage with time in the initially dry profile at depths 10, 20, 30, 40, and 55 m for year 10 . 74 26. Cumulative drainage with time in the initially wet profile at depths 10, 20, 30, 40, and 55 m for year 10 . 75 27. Cumulative drainage with time in the initially dry profile at depths 10, 20, 30, 40, and 55 m for year 30 . 76 28. Cumulative drainage with time in the initially wet profile at depths 10, 20, 30, 40, and 55 m for year 30 . 77 29. Annual drainage past the base of the profile for the 30-year transient pile simulation from both dry and wet initial conditions 79 30. Distribution of moisture in the profile for simulation of year 6 with plants 80 31. Distribution of moisture in the profile for simulation of year 6 without plants 81 ix LIST OF ILLUSTRATIONS--Continued Figure Page 32. Total water storage to a depth of 10 m for simulation of year 6 with and without plants 83 33. Schematic of the profile for sensitivity 88 34. Distribution of precipitation from days 120 to 150 of simulation 90 35. Distribution of potential evapotranspiration (PET) from days 120 to 150 of simulation 90 36. Root growth rates for the original and perturbed sensit- ivity cases 92 37. Rooting density with depth to 80 cm for the original and perturbed sensitivity cases 94 38. Relative sensitivity of suction head versus depth on days 120 and 150 for perturbations of hydraulic conductivity (K ) of the soil cover . 97 s 39. Relative sensitivity of suction head versus depth on days 120 and 150 for perturbations of hydraulic conductivity (X ) of spent shale compacted to 1.2 g/cm3 98 s 40.