Gas Pipeline System

The U.S. natural gas pipeline network stretches over 3 million miles, making it one of the largest infrastructure systems on Earth. Gas flows from wellhead to burner tip through a series of increasingly smaller pipes, each segment designed for a different pressure and purpose.

The system has four tiers. Gathering lines (2-8 inch diameter, low pressure) collect gas from individual wells and move it to processing plants, where impurities (water, CO2, hydrogen sulfide) are removed. Transmission pipelines (20-42 inch diameter, 30-80 bar pressure) carry processed gas over hundreds or thousands of miles. Compressor stations every 60-100 miles re-pressurize the gas to overcome friction losses, consuming 3-5% of throughput as fuel. Underground storage (depleted reservoirs, salt caverns, aquifers) buffers seasonal demand swings: injecting gas in summer when demand is low, withdrawing in winter when heating demand peaks. Distribution mains (2-24 inch, low pressure) deliver gas to homes and businesses in local networks.

Trace a molecule. Gas leaves a Permian Basin well, enters a gathering line, reaches a processing plant in West Texas, enters a 36-inch transmission line at 70 bar, passes through 8 compressor stations over 1,200 miles, enters storage in Louisiana, and is withdrawn in January to heat a home in Atlanta via a 4-inch distribution main.

Quantify the compressor fuel cost. A pipeline moves 1 billion cubic feet per day. At 3-5% fuel consumption, 30-50 million cubic feet per day powers the compressors.

Why can't the pipeline simply start at higher pressure to avoid compressor stations?

Friction limits. Gas loses pressure continuously through pipe friction. No initial pressure is high enough to push gas 1,000+ miles without recompression. Compressor stations are the pipeline equivalent of repeater stations on a fiber optic cable.

The gas pipeline system is the energy system behind the energy system, delivering the fuel that powers 43% of U.S. electricity.

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