Working Gas: The Volume of Natural Gas Available for Withdrawal

An in-depth exploration of working gas in the context of natural gas storage, including its definition, measurement, and industrial significance.

Working gas refers to the volume of natural gas stored in an underground reservoir that is available for withdrawal. This term is mainly used in the context of natural gas storage and is an essential measure for energy companies, utilities, and policymakers.

Definition and Measurement

Working Gas \( W_g \) can be defined as:

$$ W_g = T_g - C_g $$

where:

• \( T_g \) is the total gas in storage.
• \( C_g \) is the base or cushion gas, which is the gas volume that remains in the reservoir to maintain adequate pressure and stability.

Types of Natural Gas Storage

• Depleted Oil and Gas Reservoirs

  • Utilize former oil and gas fields.
  • Typically low-cost storage option.

• Aquifers

  • Underground, water-bearing formations converted to natural gas storage.
  • Require additional investment for conversion and maintenance.

• Salt Caverns

  • Hollowed-out salt formations.
  • High deliverability rates but usually smaller capacity.

Applicability in Industry

• Seasonal Demand
  • Helps in managing seasonal demand fluctuations.
• Energy Security
  • Acts as a buffer to ensure energy security during supply disruptions.
• Market Stability
  • Contributes to the balancing of supply and demand, stabilizing market prices.

Historical Context

The concept of storing working gas evolved in response to the need for reliable fuel supplies and the ability to meet peak demand periods. The development of gas storage facilities began in the mid-20th century, largely driven by the increasing importance of natural gas in the energy mix.

Examples

• United States:

  • Extensive use of depleted oil and gas reservoirs.
  • Strategic locations provide critical supply to major consumption areas, especially in winter.

• Europe:

  • Significant storage in salt caverns and depleted reservoirs.
  • Ensures supply for both industrial and residential consumers.

Special Considerations

• Regulatory Environment:
  • Varies by country, influencing the development and operation of storage facilities.
• Technological Advances:
  • Innovations in storage and extraction technologies can impact the efficiency and cost of maintaining working gas volumes.

Related Terms

• Base Gas: Also known as cushion gas; the non-withdrawable part of the total gas volume in storage.
• Total Gas: The sum of working gas and base gas in storage.

FAQs

How is working gas different from base gas?

Working gas is the volume available for withdrawal, while base gas remains in the reservoir to maintain pressure and stability.

Why is working gas important?

It ensures reliable supply during peak demand periods and contributes to market stability and energy security.

How is working gas measured?

Typically measured in billion cubic feet (BCF) or trillion cubic meters (TCM), depending on the scale of storage.

References

• Energy Information Administration (EIA). (2023). “Natural Gas Storage.”
• American Gas Association (AGA). (2022). “Understanding Gas Storage.”

Summary

Working gas is a critical component in the management and stability of natural gas supplies. By storing gas that is readily available for withdrawal, the energy industry can effectively manage seasonal demand fluctuations, ensure energy security, and maintain market stability. Understanding the dynamics of working gas is essential for stakeholders across the natural gas sector—from policymakers and energy companies to consumers and investors.