Drilling 101

drilling mud pit

What is different about the Marcellus?

There has been gas drilling in NYS for over 100 years in conventional gas plays. But a new drilling process, called “high-volume hydraulic fracturing,” has made the huge natural gas reserve in the Marcellus Shale recoverable. Drilling will most often be done horizontally in the Marcellus Shale.

Extent of Formation
Unlike other gas formations, the Marcellus is vast and continuous. Although it varies in depth and thickness, the Marcellus underlies the entire southern half of the state (and extends under PA, WV, and eastern OH) (1) Marcellus development in NY is expected to begin in the Southern Tier, along the Millennium Pipeline (which runs from Corning to Rockland County), and to radiate North from there.

Hydraulic Fracturing (also known as hydrofracking)
Unlike in conventional gas reserves, the gas in the Marcellus is trapped and dispersed throughout the shale in tiny pores, and must be released in a process called hydraulic fracturing, or fracking. In each fracking, 2-9 million gallons of water mixed with sand and chemicals are forced through the well into the formation at high pressure to fracture, or crack, the shale. Roughly half the fracking fluid remains in the ground. The rest of it (1,000,000 to 4,000,000 gallons) comes up out of the well and is considered industrial waste and must be disposed of. Each well may be fracked up to ten times during its productive life. (2)

Water Usage
Fracking requires large quantities of fresh water. Fracking the Marcellus will require many billions of gallons of water over the next 15 years. This water can be withdrawn from lakes, rivers, streams, wetlands, ponds, and wells. Because the water becomes contaminated, it may never be returned to the watershed. (3)

Fracking Fluids
Most of the recent advances in fluid technology for shale gas recovery are owned by Halliburton. The gas industry describes fracking fluids as being “like soap and oil.” However, because Halliburton classifies the fracking fluids as proprietary, nobody knows for sure what is in them. Samples from well blowouts and fluids pits in Colorado, Wyoming and New Mexico found fluids to contain diesel fuel and more than 200 different kinds of chemicals, over 95% of which have adverse side effects including brain damage, birth defects and cancer. (4)

Fluids Disposal
The produced water from the Marcellus Shale is toxic waste. In addition to the added chemicals, the water picks up hydrocarbons, heavy metals like arsenic, and radioactivity from the shale. (5) Billions of gallons of waste water will be produced in our area alone and will need to be trucked to a final disposal site. The most common method of disposal will be Deep Well Injection Disposal, where the waste is forced underground at high pressure into dry gas wells. (6)

Well Life
Marcellus wells are long lived. They will remain active for decades, up to 40 years. (7)

40 acre spacing

Well Spacing
Marcellus wells can be spaced in 40-acre units or 16 wells per square mile. An average town could contain up to 1,500 wells. (8) The photograph above is of the Jonah field in the Rockies; this is what 40 acre spacing gas development looks like.

Well Pad Size
When hydrofracked and drilled horizontally, Marcellus wells require large, industrial pad sites. Depending on how many well heads it contains, a pad will range from 5-15 acres.

Like all natural gas production, Marcellus wells have temporary noise pollution from drilling and fracking that will last about a month per well. In addition, compressor stations will be needed for every 100 or so wells, to bring the gas pressure in gathering lines up to that of larger pipelines. Compressor stations are permanent, extremely noisy, and run day and night.

big truck little road

All gas development creates traffic in rural areas. The large scale of development planned for the Marcellus, and the fact that it must be fracked, translates to dramatic increases in traffic compared to that generated by drilling conventional wells. One well service company, Gas Field Specialists, uses tanker trucks that can carry 5,460 gallons of fluid. If one well requires 2 million gallons of water for one fracking, that’s 366  tanker trucks hauling fresh water and 183 tanker trucks hauling waste water, for a total of 549 tanker truck trips per well, per fracking. For the average fracking, which may take 3.5 million gallons, that is 960 tanker truck trips.  In Pensylvania, the DEP estimates that one horizontal Marcellus well requires 1,000 truck trips during drilling and fracking.

two flares, farm, and new well

Air Pollution
Each well site emits air pollution. In addition to pollution from diesel generators, drill rigs, trucks and other equipment, condensate tanks and the flaring of wells are significant sources of VOC’s and nitrogen oxide, which react with sunlight to form ozone. Proposed Marcellus Shale drilling in New York will be high density. In high-density drilling areas in Colorado and Wyoming, rural communities that were once pristine now have ozone levels higher than Los Angeles. Ozone can cause a range of respiratory health problems and lung disease.(9)

(1) Pennsylvania Geology, The Marcellus Shale-An Old “New” Gas Reservoir in Pennsylvania, Vol. 38, NO.1, 2008
(3) Calculations based on water withdrawal rates by companies operating in Pennsylvania. Susquehanna River Basin Commission, Bucknell University, September 11, 2008 http://www.srbc.net/programs/projreviewmarcellus.htm
(4)Analysis of Chemicals Used in Natural Gas Production: Colorado, Theo Colborn, PhD, February 6, 2008
(6)Draft Scoping Document for Horizontal Drilling and High Volume Hydraulic Fracturing to Develop Shale and Other Low Permeability Gas Reservoirs, New York Sate Department of Environmental Conservation, 2008
(7) Industry Sources
(8)Draft Scoping Document for Horizontal Drilling and High Volume Hydraulic Fracturing to Develop Shale and Other Low Permeability Gas Reservoirs, New York Sate Department of Environmental Conservation, 2008
(9)Draft Oil and Gas Ozone Reduction Strategy, Regional Air Quality Counsel of Colorado, presented at April 10, 2008 meeting


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