Marcellus Shale

While Marcellus Shale may be most abundant in Pennsylvania, Marcellus Shale gas extraction will increase pipeline infrastructure expansion nationally.  Regardless of your opinion on unconventional natural gas extraction, even if drilling of Marcellus stopped today, an existing pipeline infrastructure exists, has been transparent fuels for decades and existing Marcellus wells require more pipelines to transport Marcellus gas to customers. Pipelines exist and are new infrastructure is eminent.

Much of the Nation’s pipeline infrastructure is more than fifty years old. Factors such as pipeline materials, fuel being transported and geography determine life expectancy of a pipeline, but generally pipelines have a 50 year life expectancy.  This factor alone presents safety concern from citizens when new infrastructure to transport Marcellus and Tar Sands appear to take precedence over replacing aging infrastructure exist.  

PSC is located in Chester County, Southeast Pennsylvania and is a prime example of a non-drilling location directly impacted by pipeline infrastructure needed to move Marcellus gas to markets.  With over 700 linear miles of natural gas pipeline beneath 760 square miles of our land and watersheds, this concentration of infrastructure is expanding in an already overly burdened geography.  

Drilling may not be in your back yard, but pipelines and the infrastructure of processing plants, compressor stations, valves, pig launchers, city gates and distribution lines being built to move Marcellus Shale fuel to market connect communities globally in the interest of pipeline safety.     

Marcellus Shale Gas Pipelines: Not All Natural Gas is the Same

One important distinction is that between conventional and unconventional gas resources. According to Canadian Association of Petroleum Producers, natural gas comes from both “conventional” (easier to produce) and “unconventional” (deeper, more difficult to produce) geological formations. The key difference between conventional and unconventional natural gas is the manner, ease and cost associated with extracting the resource. In 2005, unconventional gas represented 44% of U.S. lower-48 onshore production. In the context of pipeline infrastructure, transporting Marcellus and Utica shale unconventional gases requires additional pipelines but also expanded categories of pipelines.

Another important distinction is dry vs wet gas. Natural gas is comprised of hydocarbons; predominantly methane. Dry, or ‘cold’ gas, is almost pure methane, by nature or by having had most of the other commonly associated hydrocarbons removed. When other hydrocarbons, referred to as NGLs or natural gas liquids (ethane, butane, pentane, etc) are present, the natural gas is 'wet' - or ‘hot’. Since wet gas requires processing, the infrastructure in wet gas is more complex, requiring additional land use. Ethane, prevalent in Western Pennsylvania wet gas is the fodder for Cracker plants, which make plastics.

Sour gas is another category to consider, in all natural gas and oils. Sour gas contains significant amounts (5.7 milligrams of per cubic meter) of hydrogen sulfide (H2S). The threshold varies by area and agency as do the terms sour gas and acid gas. However, sour gas is specifically contains hydrogen sulfide in significant amounts and acid gas contains significant amounts of acidic gases such as carbon dioxide (CO2) or hydrogen sulfide. Hydrogen sulfide is toxic and damages pipelines and other equipment handling sour gas whenever water is present. This damage is referred to as sulfide stress cracking. Natural gas from some wells have been known to contain 90% hydrogen sulfide.

As with wet gas, sour natural gas must be treated to remove impurities to acceptable levels. In oil or natural gas processing plants, the removal of organosulfur compounds and hydrogen sulfide is referred to as "sweetening".

Wet, Dry, Sour; transporting Marcellus and Utica shale unconventional gases requires additional pipeline infrastructure and has expanded the volumes, categories and traditional definitions of pipelines.  Safety and siting regulation of these new Marcellus pipeline classifications is under question by communities affected by their appearance in their landscapes. Traditionally referenced types pipelines and Marcellus Shale pipelines are included on this discussion.