Marcellus Shale and Natural Gas Production in New York
Marcellus Shale is a Devonian-age rock formation deposited over 350 million years ago in a shallow inland sea located where the present day Appalachian Mountains now stand.
The shale contains organic matter that has been compressed and heated deep within the Earth creating hydrocarbons which include significant quantities of natural gas.
Natural gas in shale occurs in fractures, in the pore spaces between individual mineral grains and chemically adsorbed onto organic matter
To produce commercial amounts of natural gas from such fine grained rock, higher permeability flow paths must be created into the formation.
This is done using a technique called hydraulic fracturing, commonly referred to as “hydrofracking” or “fracking.”
A hydrofrack is where water under high pressure forms fractures in the rock, which provide pathways for gas to move to the well.
The estimate of recoverable gas from the Marcellus Shale is estimated to over 363 Tcf.
The United States uses about 19 Tcf of natural gas per year, so the Marcellus gas resource may be large enough to supply the needs of the entire nation for nearly two decades.
Concerns about Developing Natural Gas Wells in Marcellus Shale
Large amounts of water are required for the stimulation of a Marcellus Shale gas well.
Fluids recovered from the well, including both the liquids used for the hydrofrack and any produced formation brines, must be safely handled, stored, treated and disposed of properly.
Three important environmental concerns related to Marcellus Shale gas production are:
Supplying the large amounts of water needed without impacting local water resources
Avoiding degradation of small watersheds from increased erosion and sediment as large quantities of equipment and supplies are moved about on unpaved rural roads
Determining the proper methods for the safe disposal of the large volumes of spent and recovered fluids from the wells