Jawaharlal Nehru Technological University Hyderabad B.Tech III PETROLEUM PRODUCTION ENGINEERING AND DESIGN Previous Question Paper (November/December - 2020 - R15)

Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane, along with varying amounts of other higher alkanes and small percentages of nitrogen, carbon dioxide, hydrogen sulfide, or helium. It is formed deep beneath the earth's surface through the decomposition of organic matter over millions of years.

The major components include:

• Methane (CH₄): Typically 70% to 90% by volume.
• Ethane (C₂H₆), Propane (C₃H₈), and Butane (C₄H₁₀): Known as Natural Gas Liquids (NGLs).
• Impurities: Nitrogen, Carbon Dioxide, and trace amounts of Hydrogen Sulfide.

Its importance and applications are significant due to its clean-burning nature and high energy density. It is widely used for power generation, as a domestic fuel for cooking and heating, as a feedstock in the petrochemical industry for producing fertilizers and plastics, and as a cleaner alternative fuel for transportation (CNG).

Natural gas is characterized by its high calorific value, low carbon content, and absence of sulfur and particulate matter, making it an environmentally friendly fuel. It is colorless, odorless (mercaptans are added for safety detection), and lighter than air.

In India, natural gas is sourced from both onshore and offshore fields. Major sources include:

• Offshore Basins: The Mumbai High basin is the largest producer, followed by the Krishna-Godavari (KG) basin and the Cauvery basin.
• Onshore Basins: Significant production occurs in the Assam-Arakan belt, the Cambay basin in Gujarat, and the Rajasthan basin.

These resources are managed primarily by public sector undertakings like ONGC and OIL, alongside private players operating under the New Exploration Licensing Policy (NELP) and Open Acreage Licensing Policy (OALP).