Natural Gas

Composition and Formation

• Primary Component: Methane (CH4), with smaller quantities of other hydrocarbons.
• Formation:
  • Originated millions of years ago from dead organisms sunk to ocean floors.
  • Buried under sedimentary rock, undergoing transformation under intense heat and pressure to convert into gas.
• Location: Found in underground rock formations called reservoirs with porous rocks that trap gas.

Types of Natural Gas

• Dry Gas: Contains mostly methane.
• Wet Gas: Contains methane along with other compounds like ethane and butane.
  • Natural Gas Liquids (NGLs): Separated for individual sale and use in products like refrigerants and plastics.

Extraction and Processing

• Conventional Extraction: Through drilling wells.
• Unconventional Gas: Includes shale gas, tight gas, sour gas, and coal bed methane with specific extraction techniques.
• Associated Gas: Found with oil and now captured instead of flared.

Processing Steps

1. Oil and Condensate Removal: Separate oil and heavier hydrocarbons.
2. Water Removal: Purifying the gas.
3. NGL Separation: Extracting additional valuable liquids.
4. Sulfur and CO2 Removal: Further purification to achieve pipeline quality.

Transportation

• Transported through pipelines (gathering lines and feeders) to distribution centers or stored in underground reservoirs.
• Liquefied Natural Gas (LNG): Gas is liquefied for shipping across oceans.

Uses

• Domestic and Industrial Heating: Major use for natural gas.
• Electricity Generation: Emits approximately half the carbon emissions of coal.
• Fuel: Compressed natural gas for vehicles.
• Industrial Feedstock: Used in fertilizers, hydrogen fuel cells, and other processes.

Environmental Impact

• Emissions: Fewer greenhouse gases and pollutants than other fossil fuels.
• Methane Emissions: Methane is a potent greenhouse gas with 24 times the impact of CO2.
  • Escaping methane during extraction/transport contributes to climate change.
  • Leaks pose significant risks due to toxicity and explosiveness.

Recent Developments

• Technological advances, particularly in the US, have increased development due to horizontal drilling and hydraulic fracturing.