独家优惠奖金 100% 高达 1 BTC + 180 免费旋转

Reading the Natural Gas Pipeline Tea Leaves

A quick and dirty look at pipeline operations using only public sources

The next map (below) image is those pipelines with the addition of fossil plants in Texas. Gas plants are those red stars, coal plants are the black circles, and the white circles are oil (although this is not considering plant capacity or availability in any way). In some states (like New York), lots of gas plants are behind the systems of Local Distribution Companies (LDCs) and do not have access to these trunkline systems. In most places, power plants are sited such that they can get direct access to gas at the lowest rates on these bulk transfer pipelines. Also, unlike the north east, Texas is not really supposed to face gas constraints the way NY/NE can in the winter because there is just dramatically more pipeline capacity.

This third map is power plants and transmission lines as an additional reference for “where are things”. Red lines are 345 kV lines, black lines are the 100kV classes and below, blue is lines in the 200–300 kV range, and the rare purple on there at the far eastern edge is 500kV. The higher kV, the more capacity a line has, i.e., can move more power, higher limits on what power plants can put on them before they melt.

Folks in our slack were talking about specific infrastructure regions of potential interest, and the first area mentioned was Laredo to Beaumont, which sort of follows an arc a bit north of the gulf from the south western border of Texas to a bit east of Houston, which is represented on the maps above by that particularly thick bundle of natural gas pipelines in southern Texas. To take a closer look I’m going to zoom in on that section and layer in a bit more natural gas infrastructure.

There are two potentially critical pieces here, storage and compressor stations. Storage in case production falls off for some reason and compressor stations because they’re needed to keep up pressure on the system. This is a pretty critical distinction when it comes to gas vs liquid pipelines, the need for regular compressor stations to keep everything running. One compressor station is not the end of the world (although if it’s at the end of a pipeline that power plant or residential system might only get a trickle), but lose more than one and the system becomes dramatically less useful very quickly. And that’s just on the pressure side, natural gas is still very flammable and any part of the system being compromised can be super dangerous for continued operations.

The other (yes, there’s more) thing here is that Texas is producing a huge amount of the gas it’s consuming, so we need to think about where wells are located too, since those can also freeze and fail (and did!).

All of that aside, let’s layer in storage, compressor stations, and gas wells on top of that bundle of pipelines.

The small yellow dots are the wells (filtered to “gas” and “gas or oil” wells) and you can see how concentrated they are at the start of the arc mentioned above, around Laredo. This is why that area is important. You also notice an increase in the red triangles (compressor stations) as we leave the well-heavy area because demand is increasing and there are less well heads feeding onto the system and keeping pressure up that way. Finally, we have more storage (green diamonds) moving away from production as well because it’s more valuable to have the gas closer to demand, and the storage tends to be exhausted wells, which, you guessed it, were exhausted first because they’re closer to where the people are (and they’re not frac-ed wells, but we won’t get into that). One other thing I added to the above is pipeline names, which are just randomly labeled by some unknowable don’t overlap algorithm in QGIS, so not entirely useful, but this does begin to get at the business information case for all of this preamble.

So this data, these pieces of information are not necessarily simple to link together already, but with a little domain knowledge you can get going. This was all step one of my personal “how to know things about a pipeline” process. Now that we’ve gotten the GIS data, we can end the prelude and start getting into the actually business critical information (yes, this was all prelude).

1. Acquire natural gas pipeline shapefiles from either the EIA or homeland security’s GIS repositories.

2. Use those to align visually (or in code, if you want to go all Neo on it geopandas is a nice tool) with the area of interest.

3. Once you’ve identified the area you want and the overlapping pipelines get the operator names.

4. Start googling.

As I mentioned at the beginning, these interstate pipelines have associated public informational postings, and when you don’t know the ultimate parent company of a pipeline or their website before hand, that’s exactly what you search for “pipeline name informational postings”.

Returning to the map, let’s find a pipeline. First I’ll remove the wells since they’re kind of a hassle, then thicken up the pipelines a little and make the names bigger. When I click on one it turns pink-ish, so you can really make out how extensive an individual network is against the blue of everything else.

You might also notice my pipeline map doesn’t match their pipeline map and that’s because I dissolved the pipeline segments by owner-operator, and they might define the specific bits a bit differently in their internal pipeline classifications (also I dissolved on operator, not pipeline name).

So now we get into really trying to track down specific things about these pipelines. First, let’s go with the notices, and the critical ones in particular. Critical is what we care about here because they’re basically notices of “hey, important thing is happening on this system and it’s going to affect gas deliveries” major outages, force majeure events, and similar will show up here. Unfortunately I can’t show any references from last year as this pipeline only shows notices within 90 days of the current date (although you might be able to coax the site to take a different date by intercepting some information it’s passing to the table retrieval but that’s a different topic). We can see that there is one notice related to the current cold weather situation.

Clicking on it returns the following current pipeline rules which are in place until further notice:

And what you have there is a whole lot of jargon. To interpret this you need to know what firm contracts on this pipeline typically are (and in fact what the heck is a firm contract? are there non-firm contracts?), what’s a balancing agreement? What’s a transportation agreement? Does all this balancing talk mean pipeline deliveries aren’t normally enforced strictly on a day-to-day basis? (yup). But most of this is out of the scope of my small primer here, suffice it to say, these notices indicate a heightened need to make sure the system balanced in real-time (or close to it, daily), and that everyone strictly adheres to their stated contractual values. While the gas pipeline system has a higher tolerance for mismatching receipt/delivery than the electric system’s generation/load, it still does need to be balanced, and the storage on the pipeline itself is not necessarily enough alone during tougher stretches of time with high demand and possible supply disruptions.

If I select a totally different pipeline form their Interstate list (El Paso), and go to critical notices we can find one that is a bit more typical.

Clicking on the first one of these we return:

There are a couple of useful pieces of information here:

But where are those constraints? Well, El Paso has a map on their homepage with segments and a red highlighting for active constraints.

Unsurprisingly, some of those segments are in Texas, although not all, and not all parts of their Texas network are currently under constraints at all. How can we know the impact of those constraints and how the relate to business as usual? Well, it’s time to turn to locations and capacity. By navigating to the Capacity options on the left sidebar (sticking with El Paso), you can select “operationally available” and then point or segment. let’s stick with segment since we saw some in the above critical notice. This is where you begin to get hard data on pipeline operations as the design, operating, scheduled, and available capacity on the pipeline are displayed for each point or segment.

These different capacities have a whole breakdown unto themselves:

If you actually read those you might have puzzled over bits about “opposite of physical flows”, well, you can “ship” gas up and downstream on the pipes contractually, so the concept of “flow” gets pretty weird really fast. They do have an overall direction, but contractually the gas can sometimes go in a kind of loop within the same pipeline depending on the location of receipt and delivery points for a specific shipping contract.

There is also a “Cycle Selection” box, best available would the most forward in time scheduling cycle for the date we select. Intraday 3 is the final cycle of the day and the “true-up” cycle, so that’s the one I would prefer to use for any day that’s reached the end of its scheduling passes. Downloading the Excel for for the day and filtering on one of the segments (L2000) from the critical notice we can see that it has a design capacity of 597k Million BTUs but is scheduled at 0 and has 0 capacity.

Now we finally begin to return to the world of electricity.

That L2000 segment is out in western Texas (and unfortunately I guess not a place we’re super concerned about for the purposes of this storm but it’s way too late for me to go back and cherry-pick something else), but there are still some gas plants out there (snippet of map attached, El Paso pipeline highlighted in pink).

This time we’re going to download capacity by point and filter it down to the segment, L2000 (ID 940). And also compare it to the customer list as well as the map of power plants to try and cross reference some information. On the map there is a plant called “Permian Basin” right off of an El Paso pipeline. The plant is owned by Luminant, and if we search Luminant in the list of customers it returns a point on the L2000 segment, in the Texas-Permian location. This point has a capacity of a few hundred thousand MMBTUs is delivering 124k to the point today, and has an operating capacity of nearly double its design at the moment. This indicates that lots and lots of gas is being made available on the system right now, possibly to prepare for the storm. You can also back calculate the delivery amount into a rough calculation of “hey, is this a power plant or not?”

The plant data embedded in the GIS file lists this plant as having 366MW winter capacity, although the total capacity is 865MW on Luminant’s website, and is comprised of 5 CTs and two retired STs. The CTs are a bit over 30 years old at the youngest, so let’s give them a heat rate of 10. This means they would require 10 MMBtu’s of gas for every MWh of production. 124,000 MMBtu / (10*366) = 33 hours of max production, so the capacity is probably higher than that 366 value. 124,000 MMBtu / (10*865) = 14 hours of max production. So it could have ran at portion of the day flat out, or at some capacity between the 366 and 865 values all day. Either way, these back-of-the-envelope calculations do make a case for this point being one delivering to a power plant, and we got pretty far into the weeds of estimating their today fuel delivery all from public sources.

Hopefully this brief primer is helpful for someone else looking to interpret the natural gas system. As you can see there are multiple important points to be concerned about if the weather takes a turn, from wells, to compressors, to the power plants themselves. So far this storm doesn’t look remotely as severe as Uri was last year and that’s great.

Add a comment

What is your view?

Send

Related posts:

Minimize Food and Vegetable Degradation During Transportation With IoT

Retailers are grappling with the challenge to keep fruits and vegetables fresh until it reaches the consumer. Once the farm produce is harvested it starts emitting ethylene and other gases that…