Metallurgy and Corrosion Control in Oil and Gas Production

Robert Heidersbach, PhD, is the President of Dr. Rust, Inc., a consulting firm that specializes in corrosion, metallurgy, and materials consulting for a variety of international clients, including oil and gas production, military hardware, construction, litigation, and failure analysis. He was previously a faculty member in ocean engineering at the University of Rhode Island, chemical engineering at Oklahoma State, and metallurgy and materials engineering at California Polytechnic State University.

• Preface xiii1 Introduction to Oilfield Metallurgy and Corrosion Control 1Costs, 1Safety, 2Environmental Damage, 2Corrosion Control, 3References, 32 Chemistry of Corrosion 5Electrochemistry of Corrosion, 5Electrochemical Reactions, 5Electrolyte Conductivity, 6Faraday’s Law of Electrolysis, 6Electrode Potentials and Current, 6Corrosion Rate Expressions, 10pH, 10Passivity, 11Potential‐pH (Pourbaix) Diagrams, 11Summary, 12References, 123 Corrosive Environments 15External Environments, 16Atmospheric Corrosion, 17Water as a Corrosive Environment, 18Soils as Corrosive Environments, 20Corrosion Under Insulation, 21Internal Environments, 24Crude Oil, 24Natural Gas, 25Oxygen, 26Carbon Dioxide, 26Hydrogen Sulfide, 29Organic Acids, 32Scale, 33Microbially Influenced Corrosion (MIC), 36Mercury, 41Hydrates, 41Fluid Flow Effects on Corrosion, 41Summary, 41References, 424 Materials 47Metallurgy Fundamentals, 47Crystal Structure, 47Material Defects, Inclusions, and Precipitates, 48Strengthening Methods, 50Mechanical Properties, 51Forming Methods, 60Castings, 60Wrought Metal Products, 60Welding, 61Clad Metals, 65Additive Manufacturing, 65Materials Specifications, 65API – The American Petroleum Institute, 66AISI – The American Iron and Steel Institute, 66ASTM International (Formerly the American Society for Testing and Materials), 66ASME – The American Society of Mechanical Engineers, 67SAE International (Formerly the Society of Automotive Engineers), 67UNS – The Universal Numbering System, 67NACE – The Corrosion Society (Formerly the National Association of Corrosion Engineers), 68Other Organizations, 68Use of Materials Specifications, 68Carbon Steels, Cast Irons, and Low‐Alloy Steels, 69Classifications of Carbon Steels, 71Alloying Elements and Their Influence on Properties of Steel, 72Strengthening Methods for Carbon Steels, 74Quench and Tempered (Q&T) Steels, 75Carbon Equivalents and Weldability, 76Cleanliness of Steel, 76Cast Irons, 76Corrosion‐Resistant Alloys (CRAs), 77Iron–Nickel Alloys, 77Stainless Steels, 78Nickel‐based Alloys, 83Cobalt‐based Alloys, 84Titanium Alloys, 84Copper Alloys, 86Aluminum Alloys, 89Additional Considerations with CRAs, 91Polymers, Elastomers, and Composites, 93Materials Selection Guidelines, 97References, 975 Forms of Corrosion 101Introduction, 101General Corrosion, 102Galvanic Corrosion, 104Galvanic Coupling of Two or More Metals, 104Area Ratio, 105Metallurgically Induced Galvanic Corrosion, 107Environmentally Induced Galvanic Corrosion, 109Polarity Reversal, 111Conductivity of the Electrolyte, 111Control of Galvanic Corrosion, 111Pitting Corrosion, 112Occluded Cell Corrosion, 113Pitting Corrosion Geometry and Stress Concentration, 114Pitting Initiation, 115Pitting Resistance Equivalent Numbers (PRENs), 115Pitting Statistics, 116Prevention of Pitting Corrosion, 117Crevice Corrosion, 117Corrosion Under Pipe Supports (CUPS), 119Pack Rust, 120Crevice Corrosion Mechanisms, 121Alloy Selection, 121Filiform Corrosion, 122Intergranular Corrosion, 123Stainless Steels, 123Corrosion Parallel to Forming Directions, 124Aluminum, 124Other Alloys, 125Dealloying, 125Mechanism, 125Selective Phase Attack, 126Susceptible Alloys, 126Control, 126Erosion Corrosion, 127Mechanism, 127Velocity Effects and ANSI/API RP14E, 128Materials, 130Cavitation, 130Areas of Concern, 131Erosion and Erosion‐corrosion Control, 133Environmentally Assisted Cracking, 134Stress Corrosion Cracking (SCC), 135Hydrogen Embrittlement and H2S‐related Cracking, 139Liquid Metal Embrittlement (LME), 143Corrosion Fatigue, 143Other Forms of Corrosion Important to Oilfield Operations, 145Oxygen Attack, 145Sweet Corrosion, 145Sour Corrosion, 145Mesa Corrosion, 145Top‐of‐Line (TOL) Corrosion, 145Channeling Corrosion, 146Grooving Corrosion: Selective Seam Corrosion, 148Wireline Corrosion, 148Additional Forms of Corrosion Found in Oil and Gas Operations, 148Additional Comments, 152References, 1536 Corrosion Control 159Protective Coatings, 159Paint Components, 159Coating Systems, 160Corrosion Protection by Paint Films, 160Desirable Properties of Protective Coating Systems, 161Developments in Coatings Technology, 162Surface Preparation, 162Purposes of Various Coatings, 166Generic Binder Classifications, 167Coatings Suitable for Various Service Environments or Applications, 169Coatings Inspection, 169Areas of Concern and Inspection Concentration, 174Linings, Wraps, Greases, and Waxes, 176Coatings Failures, 180Metallic Coatings, 189Useful Publications, 192Water Treatment and Corrosion Inhibition, 192Oil Production Techniques, 193Water Analysis, 193Gas Stripping and Vacuum Deaeration, 194Corrosion Inhibitors, 194Cathodic Protection, 199How Cathodic Protection Works, 201Types of Cathodic Protection, 203Cathodic Protection Criteria, 214Inspection and Monitoring, 216Cathodic Protection Design, 220Additional Topics Related to Cathodic Protection, 224Summary of Cathodic Protection, 227Standards for Cathodic Protection, 227References, 2287 Inspection, Monitoring, and Testing 233Inspection, 235Visual Inspection (VT), 235Penetrant Testing (PT), 236Magnetic Particle Inspection (MT), 237Ultrasonic Inspection (UT), 237Radiography (RT), 238Eddy Current Inspection, 240Magnetic Flux Leakage (MFL) Inspection, 241Positive Material Identification (PMI), 242Thermography, 242Additional Remarks About Inspection, 243Monitoring, 244Monitoring Probes, 244Electrochemical Corrosion Rate Monitoring Techniques, 250Hydrogen Probes, 253Sand Monitoring, 254Fluid Analysis, 255Naturally Occurring Radioactive Materials (NORM), 257Additional Comments on Monitoring, 258Testing, 258Hydrostatic Testing, 258Laboratory and Field Trial Testing, 260References, 2628 Oilfield Equipment 265Drilling and Exploration, 265Drill Pipe, 265Tool Joints, 268Blowout Preventers (BOPs), 268Wells and Wellhead Equipment, 269History of Production, 270Downhole Corrosive Environments, 271Annular Spaces, 275Types of Wells, 275Tubing, Casing, and Capillary Tubing, 277Corrosion Inhibitors for Tubing and Casing in Production Wells, 280Internally Coated Tubing for Oilfield Wells, 283Wireline, 285Coiled Tubing, 285Material and Corrosion Concerns with Artificial Lift Systems, 286Facilities and Surface Equipment, 291Piping, 291Storage Tanks, 293Heat Exchangers, 297Other Equipment, 301Bolting, Studs, and Fasteners, 301Problems with Bolted Connections, 306International Bolting Standards, 307Flares, 312Corrosion Under Insulation, 312Pipelines and Flowlines, 319Pipeline Problems and Failures, 319Forms of Corrosion Important in Pipelines and Flowlines, 321Repairs and Derating Due to Corrosion, 323Casings for Road and Railway Crossings, 323Pipeline and Flowline Materials, 324Pipeline Hydrotesting, 326Seawater Injection Pipelines/Flowlines, 327External Corrosion of Pipelines, 327Internal Corrosion of Pipelines, 330Inspection, Condition Assessment, and Testing, 332Offshore and Marine Applications, 336Offshore Pipelines, 336Offshore Structures, 337References, 342Index