Natural Gas 101

Summary

Natural gas, primarily methane, is formed from the remains of ancient organisms buried under layers of sediment and subjected to heat and pressure. Extracted from underground reservoirs, it can be categorized as dry or wet gas. Wet gas contains additional hydrocarbons, which can be sold as separate products. Natural gas is used for heating, electricity generation, and as a fuel for vehicles. While it produces fewer greenhouse gases compared to coal, its extraction can lead to methane leaks, a potent greenhouse gas. Advances in drilling technologies have led to increased natural gas development, though environmental concerns persist.

Takeaways

• 😀 Natural gas is primarily composed of methane (CH4) and formed millions of years ago from dead organisms under heat and pressure.
• 😀 Natural gas is trapped underground in reservoirs by impermeable rock, which acts as a cap rock, keeping it stored until extraction.
• 😀 There are two main types of natural gas: dry gas (mostly methane) and wet gas (contains additional compounds like ethane and butane).
• 😀 Natural gas liquids (NGLs), such as ethane and butane, are extracted from wet gas and can be used in various industries, including refrigerants and plastics production.
• 😀 Conventional natural gas is extracted through drilling wells, while unconventional forms like shale gas and tight gas require specialized extraction techniques.
• 😀 Associated gas is found alongside oil in reservoirs and was once flared but is now captured and used for various purposes.
• 😀 After extraction, natural gas is processed to remove impurities, oil, water, and other liquids to achieve pipeline-quality dry natural gas.
• 😀 Natural gas is transported via pipelines to distribution centers or stored in underground reservoirs. In some cases, it is liquefied (LNG) for shipping.
• 😀 The primary uses of natural gas include domestic heating, electricity generation, vehicle fuel, and as a feedstock in chemical processes.
• 😀 Natural gas development, especially in the U.S., has increased due to advances in horizontal drilling and hydraulic fracturing techniques.
• 😀 While natural gas emits fewer greenhouse gases compared to other fossil fuels, it still contributes to CO2 emissions, and methane leaks from extraction and transportation pose significant climate change risks.

Q & A

What is natural gas primarily composed of?

Natural gas is primarily composed of methane (CH4), with smaller quantities of other hydrocarbons.

How was natural gas formed?

Natural gas was formed millions of years ago when dead organisms sank to the bottom of the ocean, where they were buried under sedimentary rock and subjected to intense heat and pressure. This process transformed the organisms into gas over millions of years.

Where is natural gas typically found?

Natural gas is typically found in underground rocks called reservoirs, where it is trapped by impermeable rock known as cap rock.

What is the difference between dry and wet natural gas?

Dry natural gas consists mostly of methane, while wet natural gas contains methane along with other compounds such as ethane and butane. The additional hydrocarbons in wet gas can be separated and sold as Natural Gas Liquids (NGLs).

What are Natural Gas Liquids (NGLs) and how are they used?

Natural Gas Liquids (NGLs) are compounds like ethane and butane found in wet natural gas. They can be separated and sold for various uses, such as in refrigerants and to produce products like plastics.

What are the key extraction techniques for unconventional natural gas?

Unconventional natural gas, such as shale gas, tight gas, sour gas, and coal bed methane, requires specific extraction techniques, such as hydraulic fracturing and horizontal drilling.

What is Associated gas and how was it treated in the past?

Associated gas is natural gas found in reservoirs alongside oil. In the past, it was often flared or burned as a waste product, but nowadays it is captured and used.

What are the main steps in processing natural gas after extraction?

After extraction, natural gas undergoes four main processing steps: oil and condensate removal, water removal, separation of Natural Gas Liquids, and sulfur and carbon dioxide removal.

How is natural gas transported after processing?

Processed natural gas is transported through pipelines called feeders to distribution centers or stored in underground reservoirs for later use. In some cases, it is liquefied and shipped in large tankers as Liquefied Natural Gas (LNG).

What are the environmental benefits and concerns associated with natural gas?

Natural gas produces fewer greenhouse gas emissions and air pollutants compared to other fossil fuels. It emits about half the carbon emissions of coal when used for electricity generation. However, methane is a potent greenhouse gas, and natural gas leaks during extraction and transportation can contribute to climate change.