MINERALOGICAL ASSOCIATION OF CANADA SHORT COURSE HANDBOOK VOLUME 7, MAY 1981 EDITED BY: F.J. LONGSTAFFE CLAYS AND THE RESOURCE GEOLOGIST A short course sponsored by the Mineralogical Association of Canada and held Immediately following their 1981 Annual Meeting, at the University of Calgary, Calgary, Alberta, May 14th-16th. THE AUTHORS: W.R. Almon Davies, Almon and Associates, Inc. Houston, Texas J.R. Boles Department of Geological Sciences University of California Santa Barbara, California G.W. Brindley Department of Geosciences and Materials Research Laboratory Pennsylvania State University University Park, Pennsylvania D.K. Davies Davies, Almon and Associates, Inc. Houston, Texas J. Hower Department of Geology University of Illinois at Urbana-Champaign Urbana, Illinois I.E. Hutcheon Department of Geology and Geophysics University of Calgary Calgary, Alberta UB/TIB Hannover 89. 101 774 745 "i Denver, Colorado ^ ^ ^ ^ ^ ; *****************************> w.im»»mljla*********
T A B L E OF C O N T E N T S ZOS3 (?) CHAPTER 1 STRUCTURES AND CHEMICAL COMPOSITIONS OF CLAY MINERALS G - w - Brindley 1 ^ Basic Structures of Clay Minerals 2 Tetrahedral and Octahedral Sheets 2 The Prototype Layer Structures L 4 Classification of Layer Silicates related to Clay Minerals... 4 Structures and Compositions of 1:1 Type Layer Silicates 7 Kaolinite-Group Minerals 7 Serpentine-Group Minerals 7 Structures and Compositions of 2:1 Type Layer Silicates 8 Pyrophyllite and Talc 8 Smectites 8 Vermiculites 12 Micas (Illites) 13 Chlorites 14 Sepiolites, Falygorskites 15 Interstratifled Layer Silicates 17 References 19 CHAPTER 2 X-RAY IDENTIFICATION (WITH ANCILLARY TECHNIQUES) OF CLAY MINERALS G.W. Brindley 22 22 Sample Preparation 23 Oriented Samples 24 Random Samples 24 Identification based on Oriented Sample Da a 25 Minerals with Long Basal Spacings, >20 A t 25 Non-Swelling Minerals with Layer Spacings, 7-15 A 28 Swelling Minerals with Predominantly One Type of Layer 28 Minerals with Randomly Mixed Layers 30 Identification based on Random Sample Data 31 Polytypic Varieties 31 b- Parameter Measurements 33 Concluding Remarks 34 Acknowledgment 35 References 35 CHAPTER 3 X-RAY DIFFRACTION IDENTIFICATION OF MIXED-LAYER CLAY MINERALS J. Hower 39 ^g Diagenetic mixed-layer clay minerals!.!!!!!!! 40 iv
"(001)" diffraction profiles of mixed layer clay minerals 41 IUite/Smectite 41 Chlorite/Smectite 52 Conclusions 55 Acknowledgments 57 References 58 CHAPTER 4 SHALE DIAGENESIS J. Hower 60 60 Burial depth-dependent mineralogical variations in shale 61 Interpretations of shale diagenesis 67 The reaction 67 Diagenetic/detrital character of shale chemistry and mineralogy 72 Factors controlling diagenetic reaction extent 73 Implications of shale diagenesis to petroleum generation and migration 76 References 77 CHAPTER 5 FORMATION DAMAGE AND THE CRYSTAL CHEMISTRY OF CLAYS W.R. Almon & D.K. Davies 81 Abstract 81 82 Clay Composition and Reservoir Management 87 Kaolinite Family 87 Smectite and Mixed Layer Smectite/Illite Family 90 Illite 92 Chlorite 93 Occurrence in Sandstone Pores 95 Role of Bulk Analysis 95 Recommended Analytical Program 99 Conclusions 100 References 102 CHAPTER 6 CLASSIFICATION AND DIAGENESIS OF CLAY MINERALS IN TIGHT GAS SANDSTONES: CASE STUDIES IN WHICH CLAY MINERAL PROPERTIES ARE CRUCIAL TO DRILLING FLUID SELECTION, FORMATION EVALUATION, AND COMPLETION TECHNIQUES J.B. Thomas 104 104 Tight Gas Sandstones 109
Empirical Relationships Summary Acknowledgments References j-^ J CHAPTER 7 DEPOSITIONAL ENVIRONMENT AND DIAGENESIS OF PERMIAN ROTLIEGENDES SANDSTONES IN THE DUTCH SECTOR OF THE SOUTHERN NORTH SEA W - R - Almon 119 Depositional Environment and Geologic History 119 Petrology 122 Diagenesis and Depositional Environment 130 Wadi Sediments 130 Aeolian Sediments 131 Diagenetic Mineralogy 132 Dolomite 132 Iron Oxide 132 Illite 133 Kaolinite Pore Fills 134 Kaolinization of Feldspar 136 Quartz 137 Anhydrite 138 Siderite 138 Paragenetic Sequence 138 Areal Aspects of Diagenesis 139 Chemical Conditions during Diagenesis 142 Source of Diagenetic Materials 145 Conclusions 146 Acknowledgments 146 References 147 CHAPTER 8 CLAY DIAGENESIS AND EFFECTS ON SANDSTONE CEMENTATION (CASE HISTORIES FROM THE GULF COAST TERTIARY) J.R. Boles 148 148 The Gulf Coast Tertiary 148 Wilcox (Eocene) - South Texas 149 Temperature - Pressure Data 149 Shale Petrology!...!'.'. 151 Detrital Sandstone Petrology 151 Diagenetic Sandstone Petrology 153 Importance of Clay Diagenesis to Cementation 157 Reaction Timing " # 153 Reaction of Calcite to Ankerite [. 159 Volume of Cements Produced!..!!!!!!!!! 159 Summary of Diagenetic Mineral Distributions.!!!!!".!!!!!!!! 160 vi 11!)
Frio (Oligocene) - South Texas 160 Mass Transfer between Shales and Sandstones 166 References 166 CHAPTER 9 APPLICATIONS OF THERMODYNAMICS TO CLAY MINERALS AND AUTHIGENIC MINERAL EQUILIBRIA I. Hutcheon 169 169 Thermodynamics and Mineral Authigenesis 170 Theoretical Considerations 172 Units 173 G as a Function of Pressure (Solids, Liquids) 173 G as a Function of Composition (Solids, Liquids): The Equilibrium Constant (K) 173 G as a Function of Temperature (T) 175 Consequences of Equilibrium 176 Applications of Thermodynamics 177 Simple Solubility of Solids 177 Equilibria between Solids and Aqueous Species: Compositional Evolution of Interstitial Water 178 Interpretation of Calculated Phase Diagrams 180 Equilibria between Solids and Gaseous Species: CO2 Contents of Diagenetic Fluids 184 "Artificial" Diagenesis: Cold Lake Tar Sand 188 Summary 191 References 191 INDEX 194 vii