Transcript Hydraulic Fracturing is also used for
Hydraulic Fracturing, Horizontal Wells & Unconventional Oil/Gas Resources Robert A. Bauer E. Donald McKay Rend Lake College July 30, 2013
Hydraulic Fracturing is also used for: Coal Bed Methane recovery Disposal wells in bedrock Underground Gas Storage Water wells In stiff soil for remediation of contamination Hard rock underground mining Geothermal wells for energy production
Hydraulic Fracturing In Oil/Gas wells First experiment – 1947 Commercial operations – 1949 Massive hydraulic fracturing – 1970/1980s Estimated > 1 million hydraulically fractured sections of horizontal wells in U.S. & > 2 million in world.
Horizontal Wells in U.S.
First horizontal well – 1930’s Common by late 1970’s ~40 thousand in U.S. over past 60 years
Concerns:
Fracturing Fluid Water Use Where are Unconventional Resources – Shale oil/gas Seismicity Groundwater Contamination
Vertical Oil/Gas well Horizontal Oil/Gas well
Surface casing & cement down to brine waters Water Well
Surface casing & cement Intermediate casing & cement Production casing & cement
Production casing Intermediate casing Surface casing Example of steel casings & production casing
Truthland
Example of each casing cemented
Truthland
Perforation of casing for production .
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Shaped charges shoot holes through casing to open it for conventional Oil/Gas production.
limestone or sandstone
If Hydraulically Fractured .
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Pressurized water, sand, and chemicals open & extend fractures
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Hydraulic Fracturing in vertical wells
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First used in 1947 Millions of vertical wells have been fractured in U.S.
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Routine use of low volume fracturing fluids – 8,000 to 12,000 gallons of water in IL.
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Recently 1 million gallons used in vertical well in Illinois Basin – in Indiana
Over 180,000 oil wells drilled in Illinois. Records past 30 years show over 20,000 have been hydraulically fractured, virtually all in vertical wells in conventional reservoirs.
Oil & Gas Fields in Illinois Basin in Green
Horizontal Wells for Shale Oil/Gas shale Natural joints & fractures Organic rich layer shale
Joints in shale layer
All wells are not hydraulically fractured There are horizontal wells producing “naturally” in IL Perforate casing & start hydraulic fracturing
Pressurized water & sand forced into fractures opens and extends them Sand in fractures keeps them open – “props” them open
Hydraulic fracturing performed in separate stages 3 2 1 Over 300 horizontal wells in Illinois According to records up to 640,000 gallons used in one horizontal well
Micro-seismic monitoring shows extent of fracturing process
North
2,000 Feet Map View of events for a single stage. Cross-Section View of 5,000 ft horizontal well
(From esgsolutions.com)
Concerns:
Fracturing Fluid Water Use Where are Unconventional Resources Seismicity Groundwater Contamination
Example Hydraulic Fracturing Fluids
[Fayetteville Shale (Arkansas) horizontal well]
Typical Additives Used in Fracturing Fluid Additive Type Friction reducer Purpose Reduces friction between fluid and pipe Consequence of Not Using Significantly increases surface pressure and frac pump engine emissions Biocide Eliminates bacteria in the water that produce corrosive byproducts Increased risk of H2S generation by sulfate reducing bacteria and increasing corrosion Scale Inhibitor Prevents mineral deposits in the pipes Blocking of fractures and plugging the plumbing Oxygen scavenger Removes oxygen from the water to protect the pipe from corrosion Pipe corrosion sharply increased Diluted Acid Dissolves cement and minerals in perforations and helps initiate fractures Higher treating pressures and more pump emissions
(from fracfocus.org)
Water Use U.S. experience ~2 to 5 million gallons per well Avg water use in IL per DAY in Millions of gallons 2 million gallons is water used in Champaign County in about 1.5 hours
USGS 2005
North Dakota – Bakken Formation estimated 2,000 wells per year
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~11 million gallons a day 2% of Ag or 0.6% of Public supply or 0.08% of Power use in ILL Illinois - per DAY in Million gallons
USGS 2005
Flowback Waters About 5% to 50% of fracturing fluid flows back out of the well. Many chemicals are consumed or adsorbed by the rock and not returned. Usually contains dissolved minerals and formation waters which are salty - i.e. brine with trace amounts of toxic metals and radioactive isotopes.
Management of the flowback waters Treated and disposed in deep disposal wells Treated & Used in hydraulic fracturing in other wells In Penn. some using pipes to carry to next well & reuse in Penn. was up to 90% in 2012 North Dakota – Gov. urged companies to install piping systems Illinois regulations require storage in tanks at drill site and testing of water.
Concerns:
Fracturing Fluid Water Use Where are Unconventional Resources Seismicity Groundwater Contamination
Energy Information Agency
Speculative or Uncertain Model at this time Shaded area general shale oil boundary Orange – shale mature & intense oil generation Highest maturity area
Concerns:
Fracturing Fluid Water Use Where are Unconventional Resources Seismicity Groundwater Contamination
Seismic Risk from Hydraulic Fracturing Hydraulic fracturing produces micro-seismic events of magnitude -2.0 to -4.0
Only detectable by sensitive instruments in deep
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boreholes.
Not felt at surface Do not cause damage Estimated > 1 million hydraulically fractured sections in horizontal wells in U.S. and no felt seismic events
Earthquake Magnitude -4 -3 -2 -1 0 1 ~ start of being felt 2 3 4 ~ start of damage 5 6 Natural earthquake damage
Earthquake Magnitude -4 -3 -2 -1 0 1 ~Smallest earthquakes detected in Illinois by seismograph stations 2 3 4 Largest recorded earthquakes in Illinois 5 6
Earthquake Magnitude -4 Hydraulic Fracturing -3 -2 -1 0 1 1 million times less energy released 2 ~ start of being felt 3 4 ~ start of damage 5 6 31 billion times less energy released
Earthquake Magnitude -4 Hydraulic Fracturing -3 -2 -1 0 1 ~ start of being felt 2 3 4 ~ start of damage 5 One Cherry Bomb One M80
Earthquake Magnitude -4 Hydraulic Fracturing -3 -2 -1 0 1 ~ start of being felt 2 3 4 ~ start of damage 5 6 Small Apple falling 3 feet & hitting floor
Induced Seismicity Potential in Energy Technologies - National Research Council report 2012: Current process of hydraulic fracturing a well does not pose a high risk for inducing FELT seismic events.
Only TWO felt earthquakes reported in the world attributed to hydraulic fracturing in horizontal wells. Blackpool, England in April 2011 - Magnitude 2.3 earthquake. Pressure went out along a bedding plane and intersected an apparently unstable fault which was reactivated by the increase in fluid pressure.
Northeast British Columbia, Canada One magnitude 3.8 felt by workers 38 events recorded from 2009-2011 (mag 2.2 to 3.8) Occurred during hydraulic fracturing in wells in fault zone More than 8,000 high-volume hydraulic fracturing completions in NE BC with no felt seismicity.
Will hydraulic fracturing trigger our natural earthquakes?
Hydraulic fracturing many miles above our natural earthquakes!
Hydraulic fracturing only increases pressures for several hours to part of day.
Felt Reports from hydraulic fracturing in Vertical Wells -4 Hydraulic Fracturing -3 -2 -1 0 1 ~ start of being felt 2 3 4 ~ start of damage 5 6 1979 2011 Oklahoma 1984-1994 29 events British Columbia, Canada
Concerns:
Fracturing Fluid Water Use Where are Unconventional Resources Seismicity Groundwater Contamination
Dimock, Penn.
USEPA Study Community concerned about methane in water and possible contamination from gas wells/drilling in area.
USEPA sampled wells & at faucets at 64 homes Each sample analyzed for 195 constituents 5 wells - Coliform (3), Barium (2) & Arsenic (2) above the USEPA and Penn. EPA for Primary maximum contamination levels for public water supplies.
Most considered naturally occurring substances & USEPA worked with individual owners to set up treatment systems at the 5 homes.
USEPA (2012)
Duke University Studies – Penn. & New York 400 water samples – private wells & surface waters Analyzed for hydrocarbons, isotopes & radionuclide levels No deep saline brines or fracture fluids found.
Osborn (2011)
Methane Concentrations in Groundwater & Springs 239 sites NY (1999-2011) Vidic et al., 2013
French explorers in 1626 discovered Native Americans igniting gases that were seeping into and around Lake Erie In 1821, the first well (hand dug) specifically for natural gas was dug in Western New York.
Eternal flame Chestnut Ridge County Park, Western NY State Etiope, et al., 2013
Pre- and Post-Drilling Testing in Penn.
No difference found for Methane in 47 wells samples within 2,500 feet of gas wells. 1 had increase.
Water chemistry in 233 Rural water wells tested - No influences seen in comparison to pre-existing data.
(Boyer at al., 2011)
Pre- and Post-Drilling Testing Arkansas 127 domestic water wells in two counties 7 samples had high methane but isotope shows biogenic in origin – not from shale gas Major ions showed chemistry link to the two types of bedrock – not from well drilling.
USGS SIR 2012-5273
Early USEPA study found one well in West Virginia with gelling agent. 4 nearby old gas wells possible pathway.
Illinois regulation has drillers plug nearby old oil wells.
Illinois regulations requires Pre- and Post-drilling tests of rivers, lakes & groundwater (wells) – First in Nation.
Sites in Colorado, North Dakota, Pennsylvania (2) & Texas
Summary Hydraulic Fracturing Hydraulic fracturing has been practiced since 1947 Adapting hydraulic fracturing to horizontal shale gas wells began 30 years ago but expanded use in the last decade.
10s of thousands of vertical wells have been hydraulically fractured in Illinois for Oil & Gas production.
Estimated > 1 million hydraulically fractured sections in horizontal wells in U.S. – no seismic events felt – only two felt in world
Many studies performed on possible contamination – best comparison where pre- & post- drilling tests are performed Hydraulic fracturing is occurring many, many miles above our natural earthquakes located in the crystalline basement Unconventional resources of shale oil/gas in Illinois is not certain Horizontal wells & hydraulic fracturing is & can be used for conventional oil/gas resources and other tight formation that are not shale or the New Albany Shale