By Vic Hughes - February 20, 2021

How would your family, and a hundred thousand other families, like to be stuck in your cars for days at minus 16 degrees?

The death toll would be huge. It almost happened in New England in 1989.

And in Texas this week.

I was part of the 1989 Freeze and have some hopefully interesting insights.

In 1989, the weather just before Christmas was terrible. Cold temperature records were set from Texas to New England.

That year, I was responsible for a midcontinent gas gathering system that normally produced about 500 million cubic feet (MMCFD) of natural gas a day. That could supply up to 2 million New England homes. During the 1989 Freeze, we produced 30 MMCFD, roughly a 95% decline. Similar results were happening throughout the Oil Patch. Supply cratered.

Meanwhile, demand for natural gas was exploding, almost literally (more on that below). While the midcontinent temperatures were low enough to freeze gas wells, New England had dangerous arctic temperatures of minus 16 degrees. This created huge natural gas demand for home heating in a major New England town.

The city ultimately weathered that crisis through luck.

Several years later, I was fortunate enough to get to know some of the city's gas utility personnel who were operating the gas grid during the Freeze. They gave me invaluable insights into what really happened. (I promised the operators I would not name the city.)

Your city gas company takes gas from high-pressure interstate and intrastate gas pipelines. The gas then moves to customers through its lower-pressured gas distribution pipes. The gas pressure decrease as it as moves to the customers. Normally the utilities' inlet gas pressure is more than enough for them to supply gas safely.

With 1989 gas production down dramatically and demand exploding, the high-pressure gas system could not supply enough gas to meet demand. This resulted in decreasing line pressures in the high-pressure supply system, lowering the gas utilities' inlet gas pressure.

The utility's inlet pressures were so low, and dropping, that soon the distribution system pressures would be below atmospheric pressure. Air could then flow into the gas pipelines. Typically, back-flow valves stop that. Since many of the furnaces were old and converted from prior fuels (oil, coal), proper valving was a big problem.

Oxygen in natural pipelines is incredibly dangerous. Whole city blocks could be destroyed in an air/gas explosion.

To maintain safe gas pressures, the operators wanted to shed load with localized gas shutoffs. Since all non-critical gas loads had already been shutoff, only critical loads were left. This included houses and hospitals. To save the gas grid, the operators had to cutoff gas to a very large number of customers.

Whose gas to shut off?

Before options were presented to senior management (this call was getting kicked way upstairs), the operators tried to figure out what would happen to the areas that lost gas. Here's what they came up with . . .

[SNIP]