Well, at least I didn't know them until I listened to David Yoxtheimer, from Penn State's Marcellus Center for Outreach and Research. http://www.marcellus.psu.edu He spoke at the Upper Delaware Council meeting on Dec. 7, 2017.
1. There are two major shale formations in the northeast, the Marcellus and Utica shales. The Utica shale occurs beneath the Marcellus shale by several thousand feet, and that shale is mostly drilled in Ohio. The Utica shale formation might be bigger than Marcellus, containing upwards of 800 trillion cubic feet of recoverable gas compared to nearly 500 trillion cubic feet of recoverable gas in the Marcellus.
2. The Marcellus shale formation currently produces 20 billion cubic feet of gas daily, while the Utica shale produces 5 billion cubic feet per day which is about a third of all natural gas produced in the U.S.
3. Most gas in eastern Pennsylvania is known as dry gas because it consists primarily of methane. In western Pennsylvania, where the deposits didn't get "cooked" as much, the shale contains a mix of oil and natural gas liquids, along with the methane.
4. It is estimated that over 350,000 oil and gas wells have been drilled in Pennsylvania since Col. Drake's oil well in 1859. (Fascinating story -http://www.pbs.org/wg…/theymadeamerica/whomade/drake_hi.html ) The majority of these wells are not mapped and were never properly sealed, and therefore represent a potential hazard of venting methane or contaminating aquifers.
5. There are approximately 16,000 shale wells in Pennsylvania, West Virginia, and Ohio, that are drilled into the Marcellus or Utica formations, including nearly 11,000 in Pennsylvania alone.
6. For every one thousand feet of shale that is hydraulically fractured, approximately 1.5 million gallons of water is used, or 1,500 gallons per foot of shale.
7. For every gallon of fluid used to fracture a well greater than one pound of sand is used as a proppant to keep fractures open, which equates to nearly a ton of sand per foot of the shale well that is being fractured.
8. For every gallon of water used to fracture a well an approximate range of 1 to 2 thousand cubic feet of gas are produced over a well's productive life.
9. The average amount of water used to fracture a Marcellus well in Pennsylvania is 7 million gallons, of which approximately 5% returns initially and 50% may return ultimately as brine as the hydrocarbons are produced. The remainder of the fluids stay bound in the relatively dry shale.
10. A several-acre well pad typically contains 6-10 wells, which have the capacity to produce gas from two or more square miles of the shale formation.