shale gas mining presentation by brett hall, oatlands tasmania, australia
TRANSCRIPT
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%.
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.
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.
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.
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.
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
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).
Typical constituents of hydraulic fracturing fluid.
Gregory, 2011 and Ground Water Protection Council and ALL Consulting 2009.
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.
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.
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.
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.
• 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 dumping of waste water.”
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.
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.
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.”