Download Fracking - University of East Anglia

Fracking
A solution to the UK Energy Problems
or
An unacceptable step too far?
Strumpshaw and District Association
30th September 2014
Keith Tovey (杜伟贤) : MA, PhD, CEng, MICE, CEnv
Reader Emeritus in Environmental Science,
University of East Anglia
Recipient of James Watt Gold Medal
1
FRACKING
Definitions
• “ a method of mining in which cracks are created in
subteranean rocks to obtain gas, oil, or other liquids”.
• Hydraulic Fracturing using high pressure liquids is
usual way of creating cracks
• Fracking is the slang term for Hydraulic Fracturing
Tonight’s Talk
• What is Fracking? Physical Resource and Definitions
• Fracking – technical issues and examples
• Impact of Fracking on UK Energy Supply
• Where have conventional/unconventional wells been
drilled in UK & Economic Issues
• Fracking – Environmental Impacts [seismic etc]
• Summary and other issues
2
Fracking: Some Definitions
• Conventional Gas: - predominantly methane
with other hydrocarbons, carbon dioxide,
nitrogen, hydrogen sulphide etc,
Found trapped in relatively porous media
capped by an impermeable stratum. Gas
migrates upwards to a capped area.
•Unconventional Gas:
• Tight Gas: -found in relatively low
permeability rocks such as
sandstones and limestone. Some
fracturing may be needed to
enhance extraction
• Shale Gas: - found in ultra low
permeability shales. Extensive
hydro fracturing needed to extract
gas
3
Schematic geology of natural gas resources
Land Surface
Conventional
Non-associated
Gas
Sandstone
Coal Bed Methane
Seal
Conventional
Associated
Gas
oil
Tight Sand Gas
Gas rich Shale
Diagram based on US Energy Information Administration
4
Fracking: Some Definitions
• Dry Gas: - predominantly methane with little if any coproducts such as ethane, propane etc.
•
Wet Gas: contains appreciable proportions coproducts of hydrocarbon such as ethane, propane,
and butane which may be in liquid or gaseous form.
• Co-products may be liquefied as LPG or converted
into petrol and add value to gas produced.
• WET GAS is defined as having more than 0.1 US gal
of condensate per 1000 cuft.
• Reserve: Total Amount of gas in Reservoir:
Three figures: Proven, Probable, Possible
•
Resource: Amount of gas which can Technically
and/or Economically be extracted typically 10-20% of Reserve
5
Where Shales are located in UK
Biological decay of
organic at shallow
depths
Biogenic methane
Organic matter
“cooked” at depth
and pressure
Thermogenic
methane in Shale
Biogenic and Thermogenic methane
can be distinguished by isotopic means
6
Typical Fracking Installations
Large ponds (0.5 – 1ha) are needed to hold Flowback Water.
• A single Fracking
Well in
Pennsylvania
7
Surface Equipment
8
Schematic of a Shale Gas Well
Aquifer
Drilling through Aquifer & Rock Layers
Aquifer
Cemented
Steel Casing
Borehole
Cement pumped through
borehole to surround casing
Horizontal Drilling
Hydraulic Fracturing
Shale
Shale Formation
9
Schematic of a Shale Gas Well
High pressure fluid mixture creates
numerous paper-thin fractures
throughout shale.
Small fractures free trapped gas
which flows into perforated
casing and up to surface.
Fracturing fluids contain ~ 94% water, 5%
sand and up to 1% of additives such as
ACID, SCALE INHIBITORS, BIOCIDES,
FRICTION REDUCERS AND
SURFACTANTS.
Fluid is injected under pressure to stimulate
cracking of the Shale. The sand props the
cracks open to promote gas flow.
Diagrams based on Tyndall Report (2011b) and Royal Society Report (2012)
10
Fracking in a Horizontal Well
The casing has multiple
annual rings some which
can slide longitudinally to
open valves for fracking.
11
Well and Pad Configurations
In US, typically up to 6
wells per Pad
Pad
Cuadrilla are proposing
up to 10 wells per Pad
Output from a Single Shale Gas Well
250
Haynesville
Eagle Ford
Woodford
Marcellus
Fayetteville
GWh/ Year
200
150
100
50
0
1
3
5
7
9 11 13 15 17 19 21 23 25
Years of Operation
Output declines by 95% over first 3-4 years
Total output over 20 years is equivalent to two 3 MW wind
turbines
13
Estimated Gas Production: Cuadrilla Scenarios for
Bowland-Hodder Shale (2014–2040)
Low Medium
High
Cumulative Production (bcm)
19.7
40.3
76.7
Wells
190
400
810
Well Pads
19
40
81
Average annual production (bcm)
0.73
1.49
2.84
Average annual production as a percentage
of UK consumption (91bcm)
0.8%
1.7%
3.2%
Water volume (m3)
Flowback Water (m3) – for treatment
Truck Visits
Average Truck Visits per weekday
Production in single year (bcm)
1,679,800 3,359,600 6,719,200
785,838
181,750
26
1,571,675 3,143,350
363,500
720,000
53
106
0.29 -2.12 0.58 -3.57 0.58 -4.90
Average household consumption of water ~ 180 m3/year
Maximum Cumulative Production from Blackpool Area over the 25
years would be ~76 bcm or 10 months current UK supply
From Tables 2.13 – 2.14 of Tyndall (2011b) Report
14
Gas Production and demand in UK
120
Billion Cubic Metres
100
Impact of
temporary
switch to coal
generation
80
60
Actual UK production
Actual UK demand
Projected production
Projected demand
Actual Production
Actual Demand
40
20
Import
Gap
0
1998
2002
2006
2010
2014
2018
Gas supply has become critical at times – e.g. at end of March 2013 – down
to 6 hours supply following technical problems on Norwegian Pipeline.
15
Impact of Ukraine Crisis
Rakteem Katakey: (Bloomberg Press) –
The Ukrainian crisis is poised to reshape the politics of oil by
accelerating Russia’s drive to send more barrels to China,
leaving Europe with pricier imports and boosting U.S.
dependence on fuel from the Middle East.
China already has agreed to buy more than $350 billion of
Russian crude in coming years.
Such shifts will be hard to overcome: Europe, which gets
about 30 percent of its natural gas from Russia, has few viable
immediate alternatives. The U.S, even after the shale boom,
must import 40 percent of its crude oil, 10.6 million barrels a
day that leaves the country vulnerable to global markets.
16
bcm
Estimates of Total UK Production of Fracked Gas
50
45
40
35
30
25
20
15
10
5
0
2010
DECC
EIA
Cuadrilla
2020
2030
2040
2050
2060
2070
The most optimistic scenario data from above are used
Electricity Scenario assumes
• similar split of gas use for electricity / non-electricity demand
• 5% improvement in efficiency for CCGT generation plant
• Maximum generation from Fracked gas = ~36.5 TWh by 2030
Based on Figure 3.1 in Tyndall (2011b) Report
17
Impact of Fracked Gas on Electricity Generation up to 2030
Assumptions in Electricity Scenarios
Assume Highest Projection for Fracked Gas
Future Demand – Climate Change Committee (2011) estimates
• Assumes significant growth in electricity for electric
vehicles and heat pumps
• Alternative demand – limited growth in electric vehicles
and heat pumps.
Fossil Fuel/Nuclear Generation
• Existing Nuclear / Coal Stations close as published
09/09/2013
• New Nuclear completions at one reactor per year from 2021.
• New Coal with CCS as demonstration schemes @ 300 MW
per annum from 2020 & 1000 MW per annum from late 2020s
• Gas including Fracked Gas will cover any shortfall between
DEMAND and
COAL + NUCLEAR + RENEWABLE GENERATION
18
Impact of Fracked Gas on Electricity Generation up to 2030
Renewable Electricity Generation Futures
[Load Factors based on weighted averages over last 5
years]
Wind
Other Renewables: Solar, Marine, Biomass, Hydro
• Solar installation rate increases to 1 million houses a
year from 2020 – 40% houses fitted by 2030
• Tidal and Wave – up to 2 GW by 2020 and significant
expansion thereafter with Severn Barrage completed
19
by 2025
Wholesale Cost of Electricity
Wholesale Electricity Prices
12
p/kWh
10
8
Oil reaches
$130 a barrel
UK no longer
self sufficient
in gas
Langeled Line
to Norway
Severe Cold
Spells
6
4
2
UK Government Projection in 2003 for 2020
0
2001 2003 2005 2007 2009 2011 2013 2015
wholesale prices updated to 4th March 2015
Weekly volume weighted average Wholesale Prices
Wholesale prices are 2.2 times what they were in 2004
Less than10% of rise can be attributed to support for renewables
20
Cost of Energy
Wholesale Electricity Prices
12
10
UK no longer
self sufficient
in gas
p/kWh
8
Oil reaches
$130 a barrel
Severe Cold
Spells
Langeled Line
to Norway
6
4
2
UK Government Projection in 2003 for 2020
0
2001
2003
2005
2007
2009
2011
2013
2015
wholesale prices updated to 16th September 2014
Wholesale prices are over 2.5 times what they were in 2004
Domestic Prices have risen by ~ 100% over period
Less than10% of rise can be attributed to support for renewables
21
Our looming over-dependence on gas for electricity generation
Version suitable for Office 2007 & 2010
TWH (billions of units (kWh))
600
• Limited electric cars or heat pumps
500
Fracked
Gas
400
Oil
Imported
Gas
UK Gas
300
Existing Coal
200
Oil
Existing Nuclear
Existing Coal
100
Offshore
Wind
Onshore
Wind
Other
Renewables
New Coal ?
Data for modelling derived from DECC & Climate Change Committee (2011)
- allowing for significant deploymentExisting
of electric
vehicles and heat pumps by 2030.New Nuclear?
Nuclear
0
1970
Data for modelling derived from DECC & Climate Change Committee (2011)
- allowing for significant deployment of electric vehicles and heat pumps by 2030.
1980
1990
2000
2010
2020
2030
Data for demand derived from DECC & Climate Change Committee (2011)
- allowing for significant deployment of electric vehicles and heat pumps by 2030.
22
Fracking: Economic Issues
• Viability of a Shale Gas Well – defined by EUR
(Economic Ultimate Recovery).
• According to recent research (Bloomberg Feb 2013)
• “the cost of shale gas extraction in the UK is
likely to be significantly higher than in the US”.
• Cost of gas produced is reduced if high value coproducts are present in “WET” gas. [Many (most?)
wells in US are WET ].
This advantage is unlikely to be significant in UK
where much of gas is likely to be “DRY”.
Comments such as:
"We will continue to drill to hold leases, and
will continue to drill in the wet gas. But there
will be little if any drilling in the dry gas
areas“
are becoming increasingly common in US.
23
Fracking: Economic Issues
• Claims are made that Fracking will reduce cost of gas in
UK Evidence often cited from US.
• BUT nowhere has the price of exactly how much
Fracked Gas will cost been indicated.
• How can claims be made that it will be cheaper if
this information in is not forthcoming?
• Even with most optimistic scenarios, Fracked Gas will
NOT be significant until after 2030.
• Over concentration on Fracking is diverting attention
from the pressing issues of the Capacity Gap looming
post 2015
24
Fracking: Carbon Emissions
Climate Change issues
Fugitive emissions from shale gas exploitation will be higher
than conventional gas extraction.
Direct use of gas
• conventional - 199 – 207 g/kWh*
• fracked gas - 200 – 253 g/kWh* depending on regulation
Electricity generation
• Conventional gas using CCGT ~ 360 – 430 g/kWh
• Shale gas using CCGT
~ 423 – 535 g/kWh *
• Coal
~ 837 – 1130g/kWh *
• Fracked gas would help in decarbonising electricity supply
in comparison to coal.
• BUT coal use in generation is set to decline significantly.
• Fracked gas is worse than conventional gas and much
worse than nuclear or renewables and increase in gas
use would jeopardize decarbonisation of Energy
Supply.
* Data
from Mackay& Stone (DECC 9th September 2013).
25
Fracking: Seismic Issues
• Richter scale (ML) is a logarithmic scale
• An increase by 1 indicates an energy increase of 10 times
• Suggested UK Threshold level for reporting Fracking - 0.5
– i.e. ground movement associated with traffic. Some
say threshold should be 1.0
• Fracking induced events in Lancashire caused
earthquakes of magnitude 1.5 and 2.3 or 10 and 64 times
the energy of the threshold
• Christchurch earthquake was 640 thousand times larger
• Fukushima earthquake was 400 million times larger
• Threshold of 0.5 at depth would not be perceptible: 10 – 12
traffic incidents a day might trigger this limit.
• Consequences of Lancashire incidents
– Small events up to 0.5 occurred during Fracking. The 1.5
& 2.3 events occurred 10 hours after Fracking ceased below level of the occasional earthquake in UK.
– [some damage reported at base of well, but no damage to
casing through aquifer].
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Perception of Seismic Events
Seismic effects of Fracking usually have magnitude ~ 0.5 to 1.0.
One Lancashire event reached 2.3
Magnitude UK frequency
Impact at surface
1.0
100s per year
Not felt, except by a very few under especially
favourable conditions.
2.0
~ 25 per year
Not felt, except by a very few under especially
favourable conditions.
3.0
~ 3 per year
Felt by few people at rest or in the upper
floors of buildings; similar to the passing of a
heavy truck.
4.0
~ 1 every 3–4
years
Felt by many people, often up to tens of
kilometres away; some dishes broken;
pendulum clocks may stop.
5.0
1 every 20+
years
Felt by all people nearby; damage negligible
in buildings of good design and construction;
few instances of fallen plaster; some chimneys
broken.
27
Historic Seismicity
in UK
Incidence of
Earthquakes in UK
1382 – 2012
Magnitude
>5
4–5
3- 4
2–3
<2
Red dots – Natural
Blue dots – coal mining
Royal Society Report (2012)
28
Methane Contamination of Groundwater
These are Peer Reviewed Journals
The dramatic videos on You-Tube of tap water igniting
were claimed to be caused by Fracking. Naturally
occurring biogenic methane was the cause in most cases,
and not FRACKING.
29
Impact of Large Scale Development of Fracking
If US model is followed
UK may require several
tens of thousands of
wells to make a
substantial contribution
to Energy Supply.
Distribution of
Fracking Wells in
Dallas – Fort Worth
Area
30
Aftermath of extensive drilling in Wyoming
31
Summary of Key Issues (1)
• There are significant Reserves of Shale Gas in UK
But do not confuse Reserves with Resource
• Most optimistic Resource extraction would potentially
provide between 7.5 & 10% of electricity generation by
2030, although could be 2 – 2.5 times that figure by 2050
But there are more important issues in Energy
Security, Climate Change and Affordability to
address post 2015
• Developers are evasive in giving an actual maximum cost
per GWh gas produced. Unless this is no more than
current wholesale price, Statements such as
“Fracking will result in cheaper Gas”
cannot be justified and are extremely misleading.
• Output from a single well drops by 80+% in first 2 years
of operation. Large scale extraction in UK could lead to
tens of thousands of wells in UK.
32
Summary of Key Issues (2)
• Seismic Risk is very small indeed
• Contamination of ground water by methane / other chemicals
might occur in a well failure or spillage for surface facilities.
• Over dramatic videos of ignition of water from taps are
misleading as these are often of biogenic methane
• Adequate Regulation needed, but this will increase costs.
• Large quantities of water are needed
• Sand and Additives (some of which are toxins) are added.
• Flowback Fluid ~ 50% of injected fluids contains
contaminants as above and naturally occurring chemicals
and naturally occurring Radioactive Material (NORM).
In Summary
• Fracking could marginally help to improve Energy Security in
UK
• Questionable whether it would in fact be cheaper than at
present
• Climate Change Targets would be jeopardized if there were a
consequential shift from Renewables and Nuclear
33
34
The following slides were not used in the
actual presentation, but have been in
previous versions
35
Imported Gas: Where does the UK gas come from?
800
600
400
TWh
Exports go primarily to
Belgium and Ireland
Total Imports
Total Exports
Net Imports
200
0
-200
-400
5.2%
0.7%
2000 2002 2004 2006 2008 2010 2012
UK Imports 2012
12.0%
41.5%
41.0%
Belgium
Netherlands
Norway
LNG Middle East
LNG Other
Gas is traded on the
international Market and
prices have become
significantly more volatile
since UK became a net
importer.
36
Differences between Sandstone and Shale
Sandstone
Large Pores
From British Geological Survey Presentation
Shale
Microscopic Pores
37
Location of Wells drilled for Gas and Oil.
Yellow dots show locations where gas has flowed
38
Sources of information
•
•
•
•
•
•
•
•
•
•
•
DECC (2012) Shale Gas Briefing Note
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/48332/5057background-note-on-shale-gas-and-hydraulic-fractur.pdf
DECC (2013) About shale gas and hydraulic fracturing (fracking)
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/226040/About
_Shale_gas_and_hydraulic_fracking.pdf
EIA (2013) Annual Energy Outlook 2013 http://www.eia.gov/forecasts/aeo/
Mackay DJC & Stone J (2013) Potential Greenhouse Gas Emissions Associated with Shale Gas
Extraction and Use. DECC
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/237330/MacKa
y_Stone_shale_study_report_09092013.pdf
Royal Society (2012). Shale Gas Extraction in the UK
http://royalsociety.org/policy/projects/shale-gas-extraction
Smith, N.; Turner, P.; Williams, G.. 2010 UK data and analysis for shale gas prospectivity. In:
Vining, B.A.; Pickering, S.C., (eds.) Petroleum Geology : From Mature Basins to New Frontiers :
Proceedings of the 7th Petroleum Geology Conference. Geological Society of London, 10871098. (see also
http://nora.nerc.ac.uk/13090/)
Tyndall (2011a). Shale gas: a provisional assessment of climate change and environmental
impacts.
http://www.tyndall.ac.uk/sites/default/files/coop_shale_gas_report_final_200111.pdf
Tyndall (2011b). Shale gas: an updated assessment of environmental and climate change
impacts
http://www.cooperative.coop/Corporate/Fracking/Shale%20gas%20update%20%20full%20report.pdf
UKOOG (2013) Community Engagement Charter: Oil and Gas from Unconventional Reservoirs
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/225851/Public
ation_UKOOG_communityengagementcharterversion6.pdf
Osborn, SG, A Vengosh, NR Warner, RB Jackson. (2011). Methane contamination of drinking
water accompanying gas-well drilling and hydraulic fracturing. Proceedings of the National
Academy of Sciences, U.S.A. 108:8172-8176, dx.doi.org/10.1073/pnas.1100682108.
Molofsky, LJ, Connor, JA, Albert S. Wylie, AS Tom Wagner, T & Farhat, SK (2013) Evaluation of
Methane Sources in Groundwater in Northeastern Pennsylvania Vol. 51, No. 3–Groundwater: 51
(no 3): 333–349 DOI: 10.1111/gwat.12056
http://onlinelibrary.wiley.com/doi/10.1111/gwat.12056/abstract
39