Facts of Myths of the Marcellus Shale: A Scientific Perspective

Transcription

1 Facts of Myths of the Marcellus Shale: A Scientific Perspective

2 What is natural gas? Methane (CH 4 ; 70-98%), ethane, hexane, propane Trapped in organic sedimentary rock Devonian to Pennsylvanian in age (400 mya-250 mya)

3 Proven reserves, fossil fuels Oil 50 years World consumption = 30 billion barrels year New discovery = 5 billion barrels year Natural gas 52 years Coal 115 years -Harrison Caruthers March 24, 2017 Submitted as coursework for PH241, Stanford University, Winter BP (2016). BP Statistical Review of World Energy 2016

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8 How is shale gas different? feet deep Horizontal drilling Hydraulic fracturing

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19 Marcellus Shale Environmental Threats 1. Water use 2. Hydraulic fracturing groundwater contamination 3. fracturing fluid spills 4. fracturing fluid disposal (bromide problem) 5. gas migration 6. air pollution 7. fragmentation of forests

20 How much is 1 million gallons of water? Relative to your use (and mine) Greenville Water Treatment plant average flow = 900,000 g/d. Capacity = two million g/d conventional treatment Pennsylvania, statewide, total withdrawals for public water supply (drinking water) = 1550 Million g d Pennsylvania, statewide, withdrawals for all uses = 9610 Million g Source: USGS, 1995, Estimated Water Withdrawals and Use in Pennsylvania, 1995

21 How much is 1 million gallons of water? Supply Greenville water storage: five storage tanks that hold approximately three million gallons of water Shenango River average flow at Transfer (2/12-1/13), g every second; 1 million gallons every 3.33 minutes Clarion River at summer baseflow, 1 million gallons every 1 min 40 sec., at high flow, 1 million gallons every 6 seconds Allegheny River a summer baseflow, 1 million gallons every 20 seconds, at high flow, 1 million gallons every 2 seconds Total River Flow, Ohio River, = 320 Billion g d= 320,000,000,000 g d

22 Hydraulic Fracturing: Does it contaminate your water? Very, very rare, with just one possible example: Pavillion Wyoming High concentration of gas wells in small area (> 100) Shallow gas ~ 2000 feet, fracturing as shallow as 1200 feet Deep ground water (up to 732 feet) Very, very poor casing practices, including unlined bore holes

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24 Fracturing Fluid - spills Bradford Co., Jan 12 Bradford Co., April 2011 Lycoming Co., Nov 2010 Summary: it happens. A relatively localized issue.

25 Fracturing Fluid - Disposal Prior to April 2011, some portion of fracturing fluid treated at sewage treatment plants and discharged to surface waters Since April 2011, zero discharge of fracturing fluid to surface waters of PA Current practice relies on recycling and deep injection wells Water purification systems are coming online

26 The Bromide Problem Bromide is a harmless salt, but reacts with chlorine and organic compounds in water treatment to form THM s, trihalomethanes, a carcinogen Water treatment plants can switch to using chloramine as a disinfectant Chloramine is more persistent, more toxic to fish and plants

27 Gas Migration Elevated methane in shallow ground water can be due to leaks from well casing Dimmock PA Can be remediated with good casing practices Important note: most water wells in Pennsylvania have some natural methane, and some have a lot of natural methane, so the presence of methane, by itself, does not implicate gas drilling. Need isotopic analysis of methane composition

28 Sources: Air Pollution Gas leakage associated with well finishing and routine operations Emissions associated with desiel engines and generators (NOx and particulates) Solution: Stricter regulations

29 Forest Fragmentation Erodible road surfaces Altered metapopulation and metacommunity dynamics Increased invasibility to exotic species Increased human pressures

30 Shale Gas environmental advantages ½ carbon footprint of coal Very, very low sulfur dioxide (.04% of coal) low NOx (20% of coal) low soot no mercury less disturbance to landscape than coal mining

31 The danger of not considering the big picture: If hydraulic fracturing were banned and shale gas not extracted: mercury emissions will increase mountaintop removal will increase NOx and SO2 emissions will increase Soot will increase SMOG will increase

32 Is natural Gas is unregulated? DEP conducts over 1000 inspections per year Pennsylvania has strict water quality laws relative to other states Public is defensive regarding water quality issues

33 Recent developments, 2012 Price of gas has plummeted to $2.00 TCF New drilling has slowed considerably Act 13 passed EPA clean air regs agreed upon EPA conducting hydraulic fracturing study Shell Oil constructing plastics plant near Pitt. Massive shift in electric generation from coal to natural gas

34 Emerging technologies Fischer Tropsch process Conversion of natural gas into synthetic petroleum products, including diesel fuel Commercially viable use of stranded gas Automobile fuel Home refueling stations Micro electric generation facilities-gas turbines

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36 Why all the irrationality? Beats me? Lack of information to provide context? Political bias, ideology?