Natural gas in Pennsylvania

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There has been much talk about the “wet” natural gas in the southwestern portion of Pennsylvania and the “dry” gas here in northeastern Pennsylvania. While they are both located beneath the Appalachian Mountains, albeit different regions, their contradicting names seem to signal a great difference between the two and how they are used.
So, what are these differences?
“Wet gas contains additional hydrocarbons when it is extracted from the Marcellus Shale,” Range Resources spokesperson Mark Windle said. “These hydrocarbons typically consist of propane, butane and ethane, which must be separated from the natural gas, or methane, before it is put into a distribution pipeline.”
Range Resources has primarily drilled in the wet gas region of the Marcellus Shale, but the company has also drilled in dry gas regions of the play.
“Wet gas is treated and processed by basically heating and cooling it repeatedly at different temperatures until the hydrocarbons are separated from the natural gas,” Windle said. “The processing facility we use from Mark West Energy Partners is designed to drop out these hydrocarbons at different temperatures and capture them. It’s actually quite a fast-moving process.
“The dry gas in northeastern Pennsylvania, on the other hand, requires very little treatment, if any, before it is ready for distribution.”
“In southwestern Pennsylvania, the gas is ‘less cooked’, or not as mature,” he continued. “The gas in northeastern Pennsylvania is more mature and therefore is dry.”
Operationally, however, extracting wet gas and dry gas do not hold many differences.
“Here at Range, we have a Zero Vapor Protocol when drilling for wet gas,” Windle said. “When wet gas is extracted, it releases vapors that can be flammable. These vapors are captured, recovered and cycled back into our pipelines by using vapor recovery units. Any vapors that were unrecoverable are safely burned off in vapor destruction units.
“The protocol is enforced for both employee and environmental safety. Obviously, flammable vapors could get ignited by a simple spark, and these vapors may also be a potential environmental hazard if they are allowed to escape. These vapors are not present in dry gas areas and so this protocol is not required.”
While dry gas is typically ready to be put on the market relatively quickly, the hydrocarbons contained in wet gas make this type of natural gas more viable economically.
“Those additional hydrocarbons — propane, butane and ethane — can be sold once they are separated from the natural gas, giving it an economic advantage over dry gas, especially with natural gas prices currently being low,” Windle said. “For example, much of the propane used in southwestern Pennsylvania is supplied from the wet gas of the Marcellus Shale.”
While propane is used for heating purposes, butane is typically used in products such as lighters and ethane is used for the development of plastics. According to Windle, the demand for ethane is beginning to rise as it is used as a cheaper yet equally effective alternative to the oil-based byproduct that is typically used in the development of these plastics.
Even though wet gas may hold these advantages, Windle said that dry gas will remain economic, especially when the price of the gas rises again.
“A higher price would make dry gas better,” he said. “That way, more methane can put onto the market and it will remain economical.”
Johnny Williams can be reached at (570) 265-1639; email: [email protected].