JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Course Objectives

This course is designed to introduce a basic study of natural gas hydrates and

coal bed methane and their properties. The student will be imparted the knowledge of:

• Overview of NGH and classification of NGH, Hydrate formation by using different methods, inhibiting hydrate formation, Different physical and chemical properties of NGH, Deacting with hydrates using heat and pressure,
• Overview of scenario of CBM, The geology of coal, Basic principles of sorption and isotherms and Reservoir characterization of CBM.

Course Outcomes

After successful completion of the course the students will be able to:

• Have good knowledge in dealing with NGH, Model different hydrate formation using both hand calculations and computer methods, understand different properties of NGH, Design line heaters foe effective transportation, have knowledge of different equilibriums of liquid water and solids with natural gas and Understand the challenges of NGH.
• Master the fundamentals of coal bed methane, construct different isotherms, evaluate different logs for CBM reservoirs and Make reservoir analysis.

UNIT - I

Introduction: Overview of natural gas hydrates- Natural gas- Water molecule- Hydrates- Water and natural gas- Free-Water- Heavy water- Units. Hydrate types and formers: Type I hydrates- Type II hydrates- Size of the guest molecule- n-Butane- Other hydrocarbons and non-hydrocarbon molecules- Chemical properties of potential guests- Liquid hydrate formers- Type H hydrates- Hydrate forming conditions- Pressure-Temperature- Composition- Other hydrate formers- Mixtures- Examples. Hydrate formation hand calculation methods: Gas gravity method- K-Factor method- Baillie-Wichert method- Comments on these methods- Examples.

UNIT - II

Hydrate formation computer methods: Phase equilibrium- Van der Waals and Platteeuw- Parrish and Prausnitz-Ng and Robinson methods- Calculations- Commercial software packages- Accuracy of these programs- Dehydration- Examples. Inhibiting hydrate formation with chemicals: Freezing point depression- Hammer schmidt equation- Nielsen-Bucklin equation- New method- Brine solutions- Comment on the simple methods- Advanced calculation methods- Inhibitor vaporization- Comment on injection rates- Kinetic inhibitors- Examples. Combating hydrates using heat and pressure: Use of heat- Heat loss from a buried pipeline- Line heater deign- Two-Phase heater transfer- Depressurization- Melting a plug with heat- Examples.

UNIT - III

Physical properties of hydrates: Molar mass - Density- Enthalpy of fusion- Heat capacity- Thermal conductivity- Mechanical properties- Volume of gas in hydrate- Ice versus hydrate- Examples. Water content of natural gas: Equilibrium with liquid water- Equilibrium with solids- Examples. Dehydration Prcesses : TEG and Molecular Sieves dehydration Processes.

UNIT - IV

Introduction: Overview of coal bed methane (CBM) in India – CBM vs Conventional Reservoirs. Geological influences on coat formation of coals – Coal chemistry – Significance of rank – Cleat system and natural fracturing.

UNIT - V

Sorption: Principles of Adsorption-The Isotherm construction-CH4 retention by coal seams-CH4 content determination in coal seams-The isotherm for recovery prediction-Model of the micro-pores-coal sorption of other molecular species. Reservoir Analysis: Coal as a reservoir-Permeability-Porosity-Gas Flow-Reserve Analysis-Well spacing and drainage area-Enhanced recovery.

TEXT BOOKS:

• 1. Natural Gas Hydrates: A Guide for Engineers, John J. Carroll, Gulf Professional Publishers, 2003.
• 2. Coal Bed Methane: Principles and Practice, R. E. Rogers, 3rd Edition, Prentice Hall, 1994.

REFERENCE BOOKS:

• 1. Natural Gas Hydrates in Flow Assurance, E. Dendy Sloan, C. Koh, A. K. Sum, A. L. Ballard, J. Creek, M. Eaton, N. McMullen, T. Palermo, G. Shoup and L. Talley, Elsevier, 2010.
• 2. Clathrate Hydrates of Natural Gases, E. Dendy Sloan, Jr., C. Koh, 3rdEdition, CRC Press, 2007.
• 3. Coal Bed Methane, Robert A. Lamarre, American Association of Petroleum Geologists, 2008.