Shale Gas Drilling Processes and Potential Impacts
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Brett looks at the potential impacts of shale gas mining on farms around Oatlands and other areas of Tasmania. Brett is a local farmer concerned about the effects of chemicals on ground water as well as other potential hazards.
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Shale Gas Drilling Processes and Potential Impacts
- 1. Shale Gas mining. Brett Hall.
- 2. Tasmanian exploration leases for Category 4 Petrochemicals. Mineral Resources Tasmania.
- 3. Coal Seam Gas Mining, Queensland. • Less than 1 Km deep. • Need to remove water. • Disposal of saline water. • 10-40% need fracturing. • High yields 60-80%.
- 4. Similarities with Shale Gas. • Government approves licences and receives royalties. • Long term effects on ground and surface water unknown. • Export market. • Conducted on agricultural land. • Little employment generated for people in the local area. • Disposal of drilling waste and water.
- 5. Exploration for shale gas. • Shale rock has low permeability. • Drilling & fracturing to verify gas. • Flow back water treated at central site. • Wells drilled range from 2-15 in a lease area. • Yield ranges from 28-40 per cent. CSIRO. Shale Gas Production.
- 6. Shale Gas Drilling. Australia, March 2012. • 12 exploration shale gas wells. • 1 Shale production well. • CSG >5,000 wells. • Shale reserves will need > 200, 000 wells. • “virtually 100% of shale gas wells will need to be fracked” Frogtech, ACOLA, Jan 2013.
- 7. Water requirements. • Each shale gas well: 10-20 fractures. • 1 fracture needs 1 mega litre of water. • 1 milk tanker holds 20,000 litres. • 50 tankers = 1 Mega litre. • 10 mega litres = 500 tanker loads. • Therefore each well will need between 500 - 1,000 tanker loads of water.
- 9. Horizontal drilling. • Typical range 600-1800 m • Extreme 3,600 m. • 2 Km radius from well Area = 1884 Ha. • Av Tas farm size: 415Ha • 4.5 farms. 2 Km. ACOLA. Unconventional Gas Production. ABS. 2011/12
- 10. Chemicals used in Hydraulic Fracturing. USA House of Representatives 2011. • Investigation on the top 14 oil & gas companies. • Between 2005 and 2009. • Used over 2,500 Fracturing products. • “More than 650 of these products contained chemicals that are known or possible carcinogens, regulated under the Safe Drinking Water Act or listed as hazardous air pollutants.” • Used 780 million gallons (2,953 million litres).
- 11. Typical constituents of hydraulic fracturing fluid. Gregory, 2011 and Ground Water Protection Council and ALL Consulting 2009.
- 12. Chemical use per fracture. • 1 Mega litre of fracking mixture per fracture. (1 million litres) • 99.5%: Water and sand. • = 995, 000 Litres. • 0.5%: Chemicals. • = 5,000 Litres of chemical per fracturing mixture.
- 13. Chemical use per shale gas well. • Fracking 10-20 times. • 5,000 Litres of chemical per fracture. • Therefore: 50,000 – 100,000 litres per well. • Average is 75,000 Litres. • Approximately 4 tanker loads of chemical.
- 14. Waste Water. • 30-70% of fracturing fluid recovered. Av 50%. • Stored in sealed dams onsite. • Some fluid recycled. • Transported for treatment. • Av 15 M l of water per well. • Av 7.5 M l waste water. • 375 tanker loads of fluid. Frogtech, ACOLA, 2013.
- 15. Impacts of gas drilling on human and animal health. Bamberger and Oswald, 2012.
- 16. Case Study 2. • Angus x Limousine cattle farm. • 96 head. • 2 active shallow gas wells on the farm. • 190 active gas wells within 8 Kilometres. • 1 paddock creek water. • 1 paddock, hill runoff water. • 1 paddock, pond water. • Good herd health. • 1-2 cow deaths annually.Page 64, Bamberger & Oswald 2012.
- 17. • Creek paddock: 60 cattle mainly 5-10 y o cows. • 17 cow deaths. (16 with dead foetuses). • 4 calves died. 21 in total or 35%. • 39 cows survived, 16 did not have a calf. (41%) • Hill Paddock: 20 Heifers 2 y o. • 1 heifer dry (5%). 0 deaths. • Pond paddock: 14 weaners. • 2 Bulls. 0 deaths. “The contamination of the creek may have been caused by the illegal
- 18. Decommissioning “Because of the high potential for ground water contamination from the wells, decommissioned wells need to be effectively sealed for hundreds if not thousands of years.” • Abandonment plan. • Open ended liability for failures into the future. Frogtech, ACOLA, 2013.
- 19. Transfer of risk to landholder. • Legacy of maintaining the well integrity. • Gas leakage from underground. • Long term effects from the mining operation. • Animal & human health. • Produce that may contain chemicals. • Fonterra NZ, not accepting milk from farms that have recycled oil or gas drilling waste on their properties.
- 20. “Door to Hell” - Turkmenistan.
- 21. US Dollars per Million British thermal units.
- 22. Contents of fracturing fluid. CSIRO, What is hydraulic Fracturing? “Further study is required to further quantify the human risks associated with the use of these chemicals in hydraulic fracturing solutions.”
- 23. World Shale gas resource estimates. Trillion cubic feet. 1 China 1275 2 USA 862 3 Argentina 774 4 Mexico 681 5 South Africa 485 6 Australia 396 7 Canada 388 8 Libya 290 9 Algeria 231 10 Brazil 226 International Energy Agency 2012. ACOLA Page 46.
Editor's Notes
- The red shaded zone depicts the areas of the state that are presently granted exploration leases or applications for exploration licences for category 4 petrochemicals. This includes coal, conventional oil, shale oil or gas and Coal Seam Gas.The Southern midlands application is 3,688 square Kilometres.State area over the 5 exploration zones is 20,117 square kilometres.
- Photo: Surat basin in Queensland June 2012.Cattle exclusion fence around the perimeter.Removing the water from the coal seam reduces the amount of pressure so the gas can then be released.Disposing of the huge amount of salty water from the coal seam is a challenge.
- Photo: Surat basin, Queensland. Shows the water separation unit on the right, some water still comes up with the gas and this tank allows it to settle. The rest of the water is removed at the plant.Japan purchases 70% of Australia’s Liquefied gas production.
- Source: CSIRO, Shale Gas production.“The main characteristic of shale is its low permeability.” Because the shales does not readily allow water or gas to readily pass through, it must be fractured to release the gas held within.“The exploration phase of shale gas production involves drilling and fracturing vertical wells to verify the presence of gas, characterise it and determine whether it can be economically produced.” Mineral Resources Tasmania stated that there would be no fracturing involved in this exploration licence. “Flow back water… best practice involves transporting it back to a treatment site, which needs a large economy of scale to be viable.”‘The number of wells drilled in the exploration phase can range from 2 to 15 wells in a lease area. Up to 30 wells may be drilled to gain more data on the pressure and geology of the resource.”“Recovery of the gas from an individual well can range from 28-40 per cent of the total amount of gas present.” The gas that is left is now subject to less pressure as there is now a pathway to the surface via the well or possibly the fractures extending up through the rock structure because of the fracturing process.
- Source: Frogtech pty ltd, Australian Council of Learned Academies (ACOLA) Jan 2013. Drill rig teams work in shifts 24/7 to put the wells in as quickly as possible. The team on this well took 4 days to complete the CSG well.
- 1 Mega litre is approximately enough water for a farmer to irrigate an acre of crop over the growing season.
- Source: Stuart, 2012. Adapted from Gregory et al 2011.This schematic diagram shows the fracturing fluid being pumped into the well, the used fracturing waste water (flowback) being stored in a lined pond.Interesting to note that the well is horizontally drilled once the shale is entered for 3 Km sideways.
- Source: ACOLA. Unconventional Gas Production: a study of shale gas in Australia. Page 56 United States Benchmark: Shale Gas Well - Horizontal Drilling IISource: Agricultural resource land management practices survey Australia, 2011/12. ABS.
- Source: USA House of Representatives, Committee on Energy and Commerce, 2011. Chemicals used in Hydraulic Fracturing.The fracturing products contained 750 chemicals and other components.“And some were extremely toxic such as benzene and lead.”Trade secret (proprietary) chemicals; “The hydraulic fracturing companies used 93.6 million gallons (354 M Litres) of 279 products containing at least 1 propriety component between 2005 and 2009.”In most cases the companies stated that they did not know the chemical composition of the products that they bought off the shelf from the chemical suppliers.“In these cases, it appears that the companies are injecting fluids containing unknown chemicals about which they may have limited understanding of the potential risks posed to human health and the environment.”
- Source: Gregory, 2011 and Ground Water Protection Council and ALL Consulting, 2009. British Geological Survey. Potential groundwater impact of shale gas in the UK. M.E. Stuart, 2011.Note here that the typical amount of chemical in the fracturing fluid is .5%.
- Photo: National Geographic.Some reuse of the waste water may be possible depending on salinity, chemical stability hardness of the solution and problems with scale formation.In the US, most of the waste water is disposed through deep underground injection.
- Source: Bamberger, M. & Oswald, R.E. 2012.Impacts of gas drilling on human and animal health. New Solutions, vol.22(1) pp. 51-77. Baywood Publishing Co., Inc.Conducted interviews with animal owners in 6 states. Colorado, Louisiana, New York, Ohio, Pennsylvania and Texas.24 Different cases were documented that included effects on pets, livestock and humans.The cause of one exposure was when a worker shut down a chemical blender during the fracturing process allowing the release of fracturing fluids into an adjacent pasture, killing 17 cows in one hour.On one farm 140 cows were exposed when the liner of a waste water impoundment was allegedly slit, as reported by the farmer, and the fluid drained into the pasture and the pond used as a source of water for the cows. Approximately 70 cows died and there was a high incidence of stillborn and stunted calves.
- Over a 3 month period 21 cattle in the creek side pasture died. Despite symptomatic treatment, deaths occurred 1-3 days after the cows went down and were unable to rise. In addition several of the surviving cows had stillborn calves with white and blue eyes. This is an interesting case as there are natural control groups running in other paddocks without access to the creek water. The cattle in pastures at higher elevation experienced no morbidity or mortality.
- Frogtech, Potential Geological Risks Associated with Shale Gas Production in Australia. Jan 2013.Typically sealing a well is accomplished by filling the well with cement to a predetermined level.The question is how long will the mining company maintain the integrity of the well after they have finished?
- The mining of shale gas effectively transfers the risks involved from the mining company over to the landowner.Who will pay for the maintenance of the well structure in future years? The government and the mining company have made their profit and moved on.Gas may continue to leak form the well into the atmosphere and groundwater. Who will monitor and test for this?The long term effects of shale gas extraction are unknown. Who will rectify any unintentional damage? Can this damage be repaired?Who will pay for any medical expenses that the people may suffer? Who will pay the replacement cost of dead, sick or diseased livestock? What about the economic losses that may occur if export markets are unavailable because of safety concerns? Fonterra NZ has announced (June 19th 2013) they will not be accepting milk from any farms that have used oil or gas drilling waste on their properties. “Waste made up of ground rock, drilling mud, and lubricant fluids is increasingly being dumped in the practice known as land farming.”The cost of testing milk for petroleum contaminants is too high.“The perception of a clean safe dairy industry was also a factor.”
- Source: Wikipedia. Karakum desert in Turkmenistan. Oil exploration in 1971 by Soviet petrochemicalscientists. The area was thought to contain substantial oil fields. Instead they found a gas reserve, the drilling rig and the camp collapsed into the crater shown here and disappeared. Large quantities of methane gas were released and posing a danger to the local people. The scientists decided the best idea was best burn the gas off over the next few days however the gas is still burning today, over forty years later!This is a good example of what can happen when there is insufficient knowledge about the risks and operators have little experience with new technology.
- In 2008 US gas prices hit a peak of $13.In 2012 the price had plummeted to a record low of $2, currently the price sits around the $4 mark.Because of the huge increase in production and the prices falling the shale gas extraction companies suffered a 9.3 billion $US loss in 2012.The Asian price is a liquefied price. You add $3 to the US gas price for liquefaction, and another $3 for transportation to Japan. At possibly 11 or 12 dollars that is 30% cheaper than Japan is currently paying from Australia. Japan buys 70% of Australia’s LNG exports.BTU is the amount of heat required to raise the temperature of 1 pound of liquid water by 1degree Fahrenheit.A BTU can be approximated as the heat produced by burning a single wooden match.I BTU = 1056 joules.The gas asset is effectively owned by all Australians, and the Government is looking to sell the asset at the low point in the market price. Economically it is a poor financial decision as the asset will only become more valuable over time..
- This chemical range may be more applicable to CSG rather than shale?
- The 10 largest estimated gas reserves listed by country in the world.