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Natural-Gas Processing

Natural-gas processing is a series of industrial procedures aimed at purifying raw natural gas to produce pipeline-quality dry natural gas. This involves the removal of various contaminants such as solids, water, carbon dioxide (CO2), hydrogen sulfide (H2S), mercury, and higher molecular mass hydrocarbons, commonly referred to as natural-gas condensate.

Natural-gas processing begins either underground or at the wellhead where raw gas is initially extracted. When natural gas is produced alongside crude oil (associated gas), it is separated from oil and processed. In contrast, non-associated gas wells produce natural gas independently from oil, and in some cases, can deliver dry gas directly to pipelines or gas plants without further separation. This direct input into the supply chain underscores the efficiency of non-associated gas production.

Key Processes in Natural-Gas Processing

  1. Separation: The first step involves separating natural gas from oil, water, and condensate. Devices such as gravity separators are commonly used.

  2. Removal of Impurities: Impurities such as CO2 and H2S are detrimental to gas quality and are removed through processes like amine gas treating.

  3. Dehydration: Water is removed to prevent pipeline corrosion and hydrate formation. Methods include glycol dehydration and molecular sieves.

  4. Fractionation: Heavy hydrocarbons in the gas are separated using a process called fractionation. This involves distillation to condense and remove heavier hydrocarbons from the gas stream.

  5. Mercury Removal: Trace mercury is sometimes present and can be removed using activated carbon beds or other chemical methods.

Natural Gas Condensate

Natural-gas condensate is a valuable by-product of natural-gas processing, consisting of hydrocarbons that are gaseous at reservoir conditions but condense into liquid form at surface conditions. This condensate is collected and can be processed further into various commercial products.

Sour Gas Processing

Sour gas, rich in H2S and CO2, requires specialized treatment to ensure safety and environmental compliance. This is primarily done through acid gas removal units which often incorporate amine treating processes.

Global Perspective

Natural-gas processing is a critical component in the global energy landscape, with facilities such as the Filyos Natural-gas Processing Plant underlining the expansion of infrastructure to meet growing energy demands. Additionally, innovations such as floating liquefied natural gas units enable processing in remote locations, unlocking new gas reserves.

Related Topics

This intricate network of processes ensures that natural gas continues to be a vital component of the global energy supply, meeting both industrial and residential energy needs efficiently and sustainably.