Shall We Gather At The River - Distinguishing Gas Gathering Pipelines From Transmission And Why It Matters

U.S. natural gas production continues to increase, with more growth expected at least through the middle of this decade to feed new LNG export capacity coming online along the Gulf Coast. Production growth will require new infrastructure, but long-distance transmission lines have become increasingly difficult to build due to entrenched environmental opposition. Meanwhile, gathering pipes have grown in size and length, blurring the lines between gathering and transmission. In today’s RBN blog, we’ll discuss what separates gathering systems from transmission pipelines, why those differences matter, and how those systems are continuing to evolve. 

America’s gas production has more than doubled since the start of the Shale Revolution, from about 50 Bcf/d in 2005 to around 104 Bcf/d in 2023. That rise in output began in gas-focused regions like the Barnett, Marcellus and Haynesville, but as more producers shifted to liquids-rich basins, an increasing proportion was produced as associated gas from crude oil-focused wells in places like the Permian, Bakken and Eagle Ford. Those oil-focused wells have become increasingly gassy over time and come with a lot of NGLs. All this has fueled a spate of new gas processing and related assets across the major shale growth basins, with production continuing to set records. As we have blogged about frequently, the U.S. will still need to add a lot of infrastructure — including gathering systems, gas processing capacity and transmission pipelines — to handle all that gas and associated NGLs. We recently covered the gas processing buildout in OMG. We also did a full series last year about the buildout of NGL pipeline infrastructure (see Get Ready) and another series about the pipelines that are increasingly taking gas to the Gulf Coast to help feed new export-driven LNG liquefaction facilities (see Gotta Get Over). Today we focus on gas gathering and transmission networks and we’ll start with a look at the basic functions of each.

Natural gas gathering systems (dashed black oval in Figure 1 below) collect raw, unprocessed supplies from production sites, usually to a central location, often for compression, before most volumes are shunted toward processing and treatment sites. If the gas does not need processing or treating, it gets directed to transmission networks. The gas is usually separated from water and other impurities right at the wellhead. For more treatment, the gathering line carries the gas to the processing plant. We’ve blogged about gathering a lot. A year ago, in Straighten Up and Fly Right, we discussed how rural gas gathering pipelines have increasingly come under federal safety regulations, adding more than 400,000 miles of onshore pipes to the oversight of the Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) starting this year.