Gas Dehydration Field Manual

Part 1 Hydrate Prediction and Prevention    Objectives    Overview         Dew Point         Dew Point Depression         Why Dehydrate?    Water Content of Gas         Introduction         Partial Pressure and Fugacity         Empirical Plots         Sour Gas Correlations         Effect of Nitrogen and Heavy Ends         Example 1-1: Calculation of Water Content in a Sour Gas Stream         Applications         Amount of Water Condensed    Gas Hydrates         What Are Gas Hydrates?         Why Is Hydrate Control Necessary?         What Conditions Are Necessary to Promote Hydrate Formation?         How Do We Prevent or Control Hydrates?    Prediction of Operating Temperature and Pressure         Wellhead Conditions         Flowline Conditions         Calculation of Temperature and Pressure at the Wellhead         Calculation of Flowline Downstream Temperature    Temperature Drop Determination         Overview         Temperature Drop Correlation         Example 1-2: Determine the Temperature Drop across a Choke    Hydrate Prediction Correlations         Overview         Vapor-Solid Equilibrium Constants         Pressure-Temperature Curves         Equations of State Calculations         Vapor-Solid Equilibrium Constants         Example 1-3: Determination of Hydrate Formation Temperature Using Vapor-Solid Constants         Pressure-Temperature Curves         Example 1-4: Determine the Hydrate Formation Temperature Using Pressure-Temperature Correlations    Hydrate Prevention         Overview         Adding Heat         Temperature Control         Chemical Injection         Comparison of Hydrate Prevention Methods         Summary of Hydrate Prevention Methods    Hydrate Inhibition         Hammerschmidt Equation         Determination of Total Inhibitor Required         Procedure for Determining Inhibitor Requirements         Example 1-5: Determining the Amount of Methanol Required in a Wet Gas Stream    ExercisesPart 2 Dehydration Considerations    Overview    Adsorption         Process Overview         Principles of Adsorption         Process Reversal         Mass Transfer Zone (MTZ)         Principles of Operation         Effect of Process Variables         Example 2-1: Determination of Pressure Drop through a Dry Bed Desiccant Dehydration Tower         Equipment         Inlet Gas Cleaning Equipment         Adsorber Tower         Insufficient Gas Distribution         Inadequate Insulation         Improper Bed Supports         Pressurization         Regeneration Gas Exchangers, Heaters, and Coolers         Regeneration Gas Separator         Control Valves         Expander Plant Molecular Sieve Applications    Desiccant Performance         General Conditions         Moisture Analyzer         Effect of Contaminants in Inlet Feed Stream         Effect of Regeneration Gases Rich in Heavy Hydrocarbons         Effect of Methanol in the Inlet Gas Stream         Useful Life         Effect of Insufficient Reactivation         Effect of High Reactivation Temperature         Areas Requiring Engineering Attention         Example 2-2: Preliminary Solid Bed Desiccant Design    Absorption         Process Overview         Principles of Absorption    Glycol Dehydration         Principles of Operation         Gas System         Glycol System         Effect of Operating Variables    System Design         Sizing Considerations         Inlet Microfiber Filter Separator         Glycol Gas Contactor         Contactor Diameter         Tray Design         Tray Spacing         Glycol Circulation Rate         Lean Glycol Concentration         Glycol-Glycol Preheater         Glycol-Gas Cooler         Glycol-Glycol Heat Exchanger         Gas-Glycol-Condensate Separator         Reconcentrator         Heat Duty         Fire Tube Sizing         Reflux Condenser         Stripping Still Column         Diameter Size         Packing         Amount of Stripping Gas         Filters         Glycol Pumps         Still Emissions    Mercury Considerations         Mercury         Treatment    Special Glycol Dehydration Systems         General Considerations         Drizo (wt.-2) Process         Cold Finger Condenser Process    Systems Utilizing Glycol-Gas Powered Pumps    Systems Utilizing Electric Driven Pumps         Example 2-3: Glycol Dehydration    Nonregenerable Dehydrator    Nonregenerable Dehydrator         Overview         Calcium Chloride Unit    Physical Properties of Common GlycolsPart 3 Glycol Maintenance, Care, and Troubleshooting    Preventive Maintenance         Scheduled Preventive Maintenance         Five Steps to a Successful Preventive Maintenance Program         Record-Keeping         Mechanical Maintenance         Glycol Care         Corrosion Control         Communication         General Considerations         Oxidation         Thermal Decomposition         pH Control         Salt Contamination         Hydrocarbons         Sludge         Foaming    Analysis and Control of Glycol         General Considerations         Visual Inspection         Chemical Analysis         Chemical Analysis Interpretation    Troubleshooting         General Considerations         High Dew Points         Glycol Loss from the Contactor         Glycol Loss from the Reconcentrator         Glycol Loss—Glycol Hydrocarbon Separator         Glycol Loss—Miscellaneous         Three-Step Approach to Troubleshooting         Glycol System Cleaning    Eliminating Operating Problems         General Considerations         Inlet Scrubber/Microfiber Filter Separator         Absorber         Glycol-Gas Heat Exchanger         Lean Glycol Storage Tank or Accumulator         Stripper or Still Column    Improving Glycol Filtration         General Considerations    Use of Carbon Purification         General ConsiderationsReferencesIndex