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Shale Gas Reserves, regulation and water demand
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Shale gas reserves, regulation and water demand
8th October 2014
IES Seminar, UWE Bristol
Jenna Brown PhD Researcher, UWE Bristol
[email protected] Regional IES Seminar | October 2014
Contents 1. Natural Gas Demand
UK Natural gas supply and demand
Origins or gas imports
2. Shale Gas Resources
Resources vs. Reserves
Security of supply
3. Water Resources
Water requirement per well
Withdrawal vs. Consumption
Potential for Water Stress
4. Regulation
Regulatory Roadmap
[email protected] Regional IES Seminar | October 2014
Natural Gas Demand
0
5
10
15
20
25
30
35
40
45
0
20
40
60
80
100
120
140 Co
ntribu
tion to
electricity generatio
n (%
) Bill
ion
cu
bic
met
ers
of n
atu
ral g
as (
bcm
)
Indigenous Production Imports
Total demand Contribution to electricity generation DECC (2014)
• The UK consumes 80-100bcm of natural gas annually
• Imports have exceeded native production since 2011 which is reflected in % contribution to electricity generation
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Projected Energy Mix
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Gas Coal Oil Nuclear Renewables Storage
However, in mitigation of climate change, natural gas is purported as a ‘transition fuel’
The contribution to electricity generation is projected to increase from 30% in 2013 to 70% by 2013
DECC Updated Energy & Emissions Projections - September (2013)
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UK Shale Gas Resources
Midland Valley (BGS, 2014) Central estimate of GIP
2,265bcm (80tcf)
Bowland-Hodder (BGS, 2013) Central estimate of GIP
37,633bcm (80tcf)
Weald (BGS, 2013) Shale oil, not gas
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Resource vs. Reserves
Resource or Gas in Place (GIP)
Technically Recoverable Resource (TRR):
~25% GIP
Reserves:
~10% GIP
Estimates can be misinterpreted in the media….
1 billion cubic meters (bcm) = 28.3 trillion cubic feet (tcf)
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Security of supply
BGS Estimate Scenario
of Bowland-Hodder
(bcm)
Gas in Place (GIP)
Technically Recoverable
Resource (TRR) =
25% GIP
Possible =
43% TRR
Probable =
32% TRR
Speculative =
25% TRR
Potential Reserves =
50% Speculative TRR
Low 23,279 5,834 2,492 1,869 1,444 736
Most Likely 37,637 9,402 4,050 3,002 2,351 1,189
High 64,598 16,142 6,938 5,154 4,050 2,011
To contextualize:
• The UK’s remaining recoverable conventional gas reserves were 490bcm (17tcf) in 2013
• Annual UK gas consumption is 80 – 100bcm (2.8 – 3.5tcf)
Therefore, the Bowland-Hodder alone contains ‘reserves’ of shale gas equivalent to at least 15 years natural gas demand
[email protected] Regional IES Seminar | October 2014
Shale Extraction
One shale gas well could produce ~85mcm of natural gas (US = ~74mcm) (Rogers, 2013) (or 3bcf (DECC, 2013))
To produce 10% of UK natural gas demand would require a cumulative 300 wells per annum (Rogers, 2013)
The UK’s geology is favourable to well pads and offer the greatest financial return to the operator
[email protected] Regional IES Seminar | October 2014
Shale Extraction
One shale gas well could produce ~85mcm of natural gas (US = ~74mcm) (Rogers, 2013) (or 3bcf (DECC, 2013))
To produce 10% of UK natural gas demand would require a cumulative 300 wells per annum (Rogers, 2013)
The UK’s geology is favourable to well pads and offer the greatest financial return to the operator
Wells pads have the potential to create a ‘paradox of intensification’ (Brown et al, 2014)
DECC’s Strategic Environmental Assessment considered the impact of 6-24 wells per pad (DECC, 2013)
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Water Use in Shale Extraction
Jiang, Hendrickson and VanBriesen (2013)
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Water Demand of Shale Gas Extraction
Process Water use per well
Duration BGS (2013) CIWEM (2013)
Drilling 0.25-4 ML 1-2ML 2-8 weeks
Hydraulic Fracturing 7-23ML 10-20ML 5-7 weeks
Production 0ML 5-20 years
(with potential to re-use some of the returned water following treatment)
1 megalitre = 1,000,000 litres or 1,000m³ An Olympic swimming pool = 2.5ML
CIWEM (2013)
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Withdrawal vs. Consumption
Shale gas is considered as being relatively ‘water efficient’ –
however, this does not consider the proportion consumed
The Strategic Environmental Assessment considered the effects of: “between 30% to 75% of the water injected during fracturing
returning as flowback” (DECC, 2013 pp.x)
This therefore means that between 25 to 70% of water used can be retained within the shale, consumed.
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Water demand of Shale Gas Extraction
Wells per well pad
4 8 12 18 24
Low High Low High Low High Low High Low High
Water requirement per well (ML)
44 97.25 88 194.5 132 291.75 198 437.625 264 583.5
Volume retained by shale (ML)
20% retained 8.8 19.45 17.6 38.9 26.4 58.35 39.6 87.525 52.8 116.7
50% retained 22 48.625 44 97.25 66 145.875 99 218.8125 132 291.75
80% retained 35.2 77.8 70.4 155.6 105.6 233.4 158.4 350.1 211.2 466.8
Low The lower estimate of CIWEM (2013) at 11ML per well
High The estimated volume by Cuadrilla (2014) based on a 4 well pad of 97.25ML
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Water Resources
Environment Agency (October, 2014)
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Water Quality Potential for water contamination exists: Groundwater
• Loss of well integrity (fracturing fluid, produced water or flowback) • Spillages at site surface on during transit (fracturing chemicals, produced
water or flowback)
Surface water • Spillages at site or during transit (fracturing chemicals or returned water)
Risks managed by HSE, EA and Local Authority – note different ‘Best Practice’ and regulation exists from USA
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environmental SCIENTIST
October issue of environmental SCIENTIST
Acknowledgement The project is funded by Lloyd’s Register Foundation, a charitable foundation
helping to protect life and property by supporting engineering-related education, public engagement and the application of research.
For more information, see: www.lrfoundation.org.uk
www.watersecuritynetwork.org www.twitter.com/water_network
Thank you
