3 Prospects for Shale Gas |
UK Shale Gas Estimates
18. There have been estimates that the UK could
be producing 10% of its current gas needs from shale gas if it
could be extracted at a commercial rate, but the British Geological
Survey (BGS) noted that this figure was based on figures from
the US a year ago, when "shale gas contributed about 10%
of their needs", which in 10 years' time would be "30%
or more". They
estimated thatby analogy with similar producing shales
in the USthe UK's shale gas reserve potential could be
as large as 150 bcm (billion cubic metres). This is
equivalent to approximately 1.5 years of the UK's current gas
consumption, or 15 years of the UK's current LNG (liquefied natural
gas) imports. However,
the Barnett Shale in the USwhich was used as an analogy
for UK shale potential in the BGS's calculationis described
by the Tyndall Centre as "an above-average producer due to
its low clay content [which allow fractures to form more easily]".
The Minister told us that DECC's "initial feeling is that
there will be reserves [in the UK] but it will not be on the scale
of Poland or the United States and it will be more complicated
to extract here than it will be in other countries".
19. In April 2011 the US Department of Energy's
independent statistical and analytical agency, the Energy Information
Administration (EIA) published their report World Shale Gas
Resources: An Initial Assessment of 14 Regions around the United
report estimated that the UK had 20 trillion cubic feet of technically
recoverable shale gas resources, or 560 bcm. This is equivalent
to 5.6 years' of the UK's current gas consumption, or 56 years'
worth of LNG imports.
The EIA estimated that in Europe, the two most promising countries
were Poland (3,740 bcm) and France (3,600 bcm), while globally
the US (17,240 bcm) and China (25,500 bcm) have the largest estimated
technically recoverable shale gas resources. The report estimate
that shale gas could increase world technically recoverable gas
resources by 40% to approximately 452,000 bcm.
20. However, the Geological Society of London
admitted that "there is currently no clear consensus within
the Earth Science community regarding the quantity of these [unconventional]
resources" either in the UK or Europe.
Professor Selley of Imperial College London told us that one of
the problems with a lot of non-conventional petroleumoil
and gasis it is very hard to work out the reserves. The
Geological Society believed that further research will improve
understanding, "for example, by helping identify 'sweet spots'
in gas plays" .
|Box 1Units and Equivalents
The BGS estimateD thatby analogy with similar producing shales in the USthe UK's shale gas reserve potential could be as large as 150 bcm [billion cubic metres]. This is very large compared with the 2-6 bcm estimate of undiscovered onshore conventional petroleum.
In 2009 the UK total demand for natural gas was approximately 1,000,000 GWh [giga/billion Watt-hours] of energy. This was equivalent to approximately 100 bcm. So the UK shale gas reserve potential was equivalent to approximately 1.5 years of the UK's current gas consumption.
DECC statistics stated that in 2009 the UK imported 110,579 GWh of liquefied natural gas [LNG]. This was equivalent to approximately 10 bcm. So the UK shale gas reserve potential could replace LNG imports for approximately 15 years.
Current wholesale gas prices are approximately 53p/therm., This would mean that 150 bcm of gas was worth approximately £28 billion. If the Government takes approximately one third of this in tax, the UK gets about £9 billion.
1 tcm = 1 trillion cubic metres = 1000 bcm 1tcf = 1 trillion cubic feet = 28 bcm
21. The British Geological Survey (BGS) believed that the
lowest shale gas exploration risk lies where "source rocks
have accompanying conventional hydrocarbon [oil and gas] fields".
Figure 1 shows UK shale gas prospects including the Upper Bowland
Shale (the source
rock for the Irish Sea conventional fields, and where Cuadrilla
are exploring), and both the Kimmerage Clay and Lias
of the Weald Basin (source rocks for the North Sea and English
Cuadrilla pointed out that "these same shales are the
source of hydrocarbons found in most of the UK's conventional
oil and gas".
With regard to this, the BGS noted that as conventional and unconventional
sources of oil and gas both derive from the same source rocks,
there will be some relationship between their productions.
22. Nigel Smith of the BGS told us:
There are probably four good plays that they [industry]
could try [...] the Namurian; the second one would be the Weald
and the Wessex Basin [...]; the third one is also quite risky,
and that is the Cambrian play in central England, going into Wales;
and then the fourth one would be looking in the fold belts [where
once flat, stacked geological strata have become curved or bent
on a regional scale].
Figure 1Onshore Shale Gas Resources
of Great Britain
Source: DECC, The Unconventional Hydrocarbon Resources
of Britain's Onshore Basins-Shale Gas, December 2010, Cover
23. Regarding the potential amounts available,
Nick Grealyof gas policy website No Hot Airtold
us, "I do not think people really quite understand the amounts
of gas that are available [
] the United States, from 2007
to 2009, increased their estimates of available resources by 40%
over two years [
] we may even be looking to an increase
on that". The
Minister told us that, "In terms of the global impact of
] it is a game changer". However, in terms of
the UK's own shale gas deposits, he said "it is too early
to know at the moment".
24. We conclude that shale gas resources in
the UK could be considerable. However, while they could be sufficient
to help the UK increase its security of supply, it is unlikely
shale gas will be a "game changer" in the UK to the
same extent as it has been in the US. It is more likely that in
countries such as Polandwith a larger reliance on gas imports
and greater potential shale gas resourcesthe impacts of
shale gas production will be significant.
UK Exploration and Production
25. Cuadrilla Resources Holdings Limited ("Cuadrilla")
describe themselves as an "English independent oil and gas
company based in Lichfield, Staffordshire, pursuing an unconventional
hydrocarbon [oil and gas] exploration programme".
Cuadrilla has drilled two wells so far; the first at Preese Hall-1,
the second at Grange Hill-1. Cuadrilla began drilling for shale
gas at Preese Hall-1located approximately five miles east
of Blackpoolin August 2010.
26. Cuadrilla completed Phase 1 of the exploration
at Preese Hall-1 in December 2010, during which they found indications
of natural gas. Phase
2 of the exploration commenced in 2011 and is expected to last
three to six months. CEO of Cuadrilla Resources, Mark Miller,
told us, "Once we have completed the wells in the exploration
phase we will try to test those wells, see how commercial they
] so we can make a commercial decision whether we want
to drill additional wells".
Mr Miller explained to us that exploration data is "kept
confidential in the early stages".
27. IGas Energy (IGas, or Island Gas) was set
up in 2003 to "produce and market domestic [UK] sourced gas
from unconventional reservoirs, particularly coal bed methane
(CBM)". Coal-bed methane, also known as "coal-seam gas",
is natural gas contained in coal-beds and is often extracted using
hydraulic fracturing technology. It is normally exploited from
virgin coal seams when the coal-bed itself is considered commercially
sub-optimal. The CEO of IGas Energy, Andrew Austin, told us that
his company has "pilot operations ongoing in coal bed methane
[CBM] right now, producing gas from our site at Doe Green in Warrington
and generating electricity and selling that".
28. IGas production licences "cover a gross
area of approximately 1,756 km2 across Cheshire, Yorkshire,
Staffordshire and the North Wales coast".
Based on "contingent recoverable resource estimates"
IGas believe they have "enough gas to supply electricity
to over seven per cent of UK households for 15 years".
While IGas has focussed on CBM resources, they have identified
"a significant potential shale resource within its acreage"
which preliminary estimates put at "1.9 trillion cubic feet
[53.2 bcm]". 
International Prospects and UK-US
29. According to the US Energy Information Administration
(EIA), during the last decade, US shale gas production has increased
fourteen-fold; it now accounts for 22% of gas production and 32%
of total remaining recoverable gas resources in the US. By 2030,
the EIA projected that shale gas would represent 14% of total
global gas supplies.
At a recent oil and gas conference in Houston, ExxonMobil's America's
Vice President for Natural Gas, Steve Kirchoff, stated his belief
that "unconventional sources of natural gas could represent
70% of US gas supplies by 2030".
30. Dr Ken Morgan, Professor of Geology and Director
of Texas Christian University's Energy Institute, has discussed
the opportunities for shale gas as a fuel in the transport sector.
An increase in the number of vehicles capable of using natural
gas fuel would allow the US to use shale gas production to displace
some of its oil imports. Of the 16-17 million barrels of oil the
US imports per day, he told us that 10 million barrels is imported,
and 70% of that is used for transport.
Dr Morgan noted that there are less than 150,000 natural gas vehicles
(NGVs) in the US at the moment, but he believes that the US could
be on the verge of entering the "Golden Age of Natural Gas".61
31. Schlumberger describes itself as "the
leading oilfield services provider".
Schlumberger's Chief Operating Officer of Oil ServicesPaal
Kibsgaardhas said that "We are convinced that the
brute force approach [in other words, drilling many individual
wells until a viable "play" of gas was found] established
in North America will not be practical overseas, either from a
financial or an operational standpoint",
adding that "We need to establish a workflow and corresponding
technology offering built around a better evaluation of shale
gas reservoirs [
] the goal will be to only drill the best
wells, and only stimulate the best intervals, while we continue
to look for [fracturing] solutions that further minimize the usage
of both water and proppant [sand]".63 Andrew GouldSchlumberger's
Chief Executive of Oil and Gas Serviceshas said that the
"drilling and producing of shale gas in Central Europe will
be very different from doing so in the southern United States
for financial and logistical, social and regulatory reasons".
32. Cuadrilla's Executive Director Dennis Carlton
told us that the current UK regulatory regime "is a better
system than [in] North America in that [
] every well has
its own drilling plan".
The Minister also claimed that the UK has a "much more cohesive
system of regulation [
] that applies across the whole of
the country. DECC
described UK regulation as "well-designed with clear lines
of responsibility among several different bodies including DECC,
the HSE, the respective Environment Agency, and Local Planning
33. Shell drew our attention to existing shale
gas exploration in Sweden, Germany, Ukraine, South Africa and
China as well as coal-bed methane assets in Eastern Australia
and China. Table 1
on page 17 sets out the estimated global unconventional natural
gas resources in place. Professor Stevens of Chatham House noted
that a National Petroleum Council Report in 2007 estimated global
unconventional gas resources at five times conventional gas reserves,
whilst Shell quoted an International Energy Agency estimate that
unconventional gas resources were equivalent to 123 years of current
However, whilst the figures seem exciting, Jonathan Craig of the
Geological Society told us that the "real issue is how much
of that gas is producible technically and commercially [
there are resources [
] a significant portionmaybe
20% to 30%of those are technically producible. You then
have an economic overlay [to consider] on top".
34. ExxonMobil Exploration and Production Poland
(EMEPP), based in Poland, told us that they were awaiting analysis
of drilling results from two wells (as of April 2011) to see whether
there further operations, including hydraulic fracturing, will
take place at these sites.
They have also undertaken surveys in three other areas, and have
commenced them in a fourth. ExxonMobil told us that they believed,
"unconventional resources will increasingly contribute to
European supply" and that they expected it to contribute
"about 10% of total supply by 2030".
1Global Unconventional Natural Gas Resources in Place (trillion
|Middle East and North Africa
|Former Soviet Union
|-Central and Eastern||2
Source: memorandum from DECC (Ev 57)
35. The Oxford Institute of Energy Studies (OIES)
identified a number of barriers to unconventional gas exploration
in Europe. It believed that to take advantage of such resources
there were five requirements for European governments:
- a much more R&D-based and
"sweet-spot" focused approach to drilling (identifying
areas of high productivity);
- new technology developments that reduced the
number of wells needed, allowed for the reduction and recycling
of water volumes used in fracing operations, and gave the ability
to drill longer laterals;
- government incentives and regulatory reform,
- the expansion of a home-grown trained service
- financial compensation to local communities.
36. DECC identified the following factors when
comparing the US situation to that in UK, Europe and the rest
of the world:
- a lack of production experience
outside of the US leads to uncertainties about the extent to which
other resources can be exploited;
- the price required to incentivise investment
will depend on the productivity and cost of the well;
- Europe has a well developed regulatory framework;
- Europe has a high population density compared
to the US;
- US law grants landowners rights over hydrocarbon
resources rather than conferring ownership on the state;
- poor gas infrastructure in developing economies;
- unconventional exploration technology and expertise
is generally confined to the US.
37. We conclude that it is important for the
UK to monitor the development of shale gas in Polandthe
"barometer of Europe" on this issueboth in terms
of exploration and regulation. We are concerned that there could
be adverse competitive consequences for the UK if Poland unilaterally
develops its shale gas resources within the EU, particularly if
their energy policy is driven by energy securityin spite
of the environmental concerns associated with hydraulic fracturingowing
to their reliance on imported gas.
The Risks of Rapid Depletion of
38. "Decline rates" describe the rate
at which the production of gas or oil wells decline over time.
For illustrative purposes, the two extremes of the decline curve
are shown in
Figure 2. Using arbitrary data, this figure demonstrates the two
characteristic ways that gas reserves can decrease with timethe
pessimistic decline rate sees the reserve deplete rapidly to zero,
while the optimistic decline rate sees a more gradual decrease
in the reserve followed by a long period of production at a low
level. The commonly held view is that the decline curve of shale
gas wells flattens out over time, but maintains a low level of
production for a significant periodthis is the optimistic
A smaller group of commentators believe that production will fall
to very small levels relatively quicklythis is the pessimistic
("exponential") view. Professor Paul Stevens of Chatham
House observed "although unconventional gas resources were
estimated to be five times those of conventional gas, there was
concern that [due to the nature of unconventional reservoirs]
their depletion rates are much faster".
39. Cuadrilla (who take the hyperbolic view)
told us that the only "scientific method currently available
to estimate these [depletion rate] factors for UK shale formations
is by analogy to commercial North American shale plays",
adding that "long-term shale gas production decline rates
remain projections rather than based on scientific facts".
They explained that "in common with other unconventional
gas wells, [a typical shale gas well] will witness steep early
production decline ratestypically of around 30% to 40%
for one to two yearsfollowed by up to 50 years of commercial
life at low decline rates, typically 5% to 7%". OFGEM told
us that "experience from the US indicates that although unconventional
gas wells deplete faster than conventional wells production levels
can be improved by re-fracturing of wells".
40. The pessimistic view of depletion rates raises
the spectre of abandoned well heads scattered over the landscape.
Over the past decade shale gas exploration and production has
moved from rural to urban areas in Texas. One of the issues encountered
has been abandoned wellswith production levels too low
to be economicthat can then not be built upon. The Texas
Railroad Commission, the State's oil and gas regulator, now requires
operators to hold bonds with the authorities (proportional to
the number of wells they are working on) in order to discourage
abandonment of well ownership. This goes to fund an "orphaned
wells" plugging programme, which is a cleanup programme set
up to deal with Texas' legacy of old abandoned wells.
Figure 2Optimistic and Pessimistic Shale Gas Depletion
41. In the crowded UK we cannot afford to
risk the creation of contaminated and abandoned sites where shale
gas production has stopped. The prospect of such a risk must be
carefully considered when licences and other permissions are granted.
We recommend that DECC should require that a fund be established
to ensure that if wells are abandoned they can be "plugged".
Such a fund could be established through a levy on shale gas well
drilling or an upfront bond. Arbitrary
The North Sea and Offshore Shale
42. Conventional oil and gas production from
the North Sea is in decline, and while there is still the potential
for significant new discoveries, they are unlikely to match the
billion barrel fields that were found in the 1970s. It is interesting
to note that the decline of UK gas production has been much quicker
than that of oil. Figure 3 shows that imports of gas grew gradually
from 2004 until by 2009 they were equivalent to 32% of consumption.
In 2009, 58% of the imports came from Norway, 16% came from the
Netherlands, 2% came via the Belgian interconnector, and 25% were
43. When pipeline transportation of natural gas
is not possible, the gas can be cooled to minus 162°C at
which point the methane condenses into a liquid, known as LNG.
This cooling to a liquid reduces the volume of the gas by approximately
600 times. This LNG can then be shipped in an LNG tanker over
long distances. Shipping LNG is an expensive process and therefore
requires high natural gas prices to make it worthwhile. The most
expensive part is building and running the liquefactions plant
that cools and condenses the gas into a liquid. Once LNG has reached
its destination, it needs to connect to a re-gasification terminal
with storage facilities and connections to regional gas pipelines.
Figure 3Natural gas production, net exports/imports
Source: DECC, Digest of UK Energy Statistics 2010,
Chart 4.1 p 97
44. The British Geological Survey (BGS) told
us that UK "offshore shale gas would have the size to affect
the [potential reserve] figures more dramatically [than onshore]",
especially as "UK onshore basins are small in comparison
with UK offshore and US onshore basins".
However, the BGS reports for DECC on unconventional resources
did not investigate offshore potential. The Tyndall Centre says
"the costs [of offshore shale] [
] would make such projects
economically unviable at current market prices".
The Geological Society believe that if the UK were to look into
offshore for unconventional gas, it would require a pioneering
approach on the part of the UK as the expertise does not exist
anywhere else. But
it is also interesting to note that deepwater drilling was once
45. Nigel Smith of the BGS told us "I think
if we went offshore, we could become [self] sufficient [in gas]",
he added that "UK onshore basins are small in comparison
with UK offshore basins".
Describing the magnitude of difference between offshore and onshore
deposits, Mr Smith told us, "say five to ten, something like
that. It is massive, the North Sea".
In a discussion of the potential benefits of offshore drilling,
Professor Selley of Imperial College London told the Committee
that "you don't have people for a start".
Nigel Smith added that it "is [also] easier to acquire [...]
[geological information, and in many cases it] already exists[s]
so in a lot of ways the data is better offshore".
On offshore shale gas exploration, Cuadrilla's CEO Mark Miller
told us "in general the procedures would be the same [
all the issues are identical whether you are onshore or offshore.
It is only the type of equipment that you work with [that is different]".
46. The Minister believed that if shale gas development
was going to occur offshore "it would be likely that it would
be horizontal drilling reached from onshore facilities".
DECC's Simon Toole then referred to operations like this at BP's
Wytch Farm oil field, "where there is a concentrated set
of wells [comparable to multi-well pads] that go out under near
The Minister added that DECC's view at the moment was that "the
costs for doing this offshore are so great that it is not going
to be viable with the price of gas where it is".
47. There is substantial evidence that UK
offshore unconventional gas resources could dwarf the potential
onshore supplies. While these might be economically unviable at
present, "uneconomic" reserves can become economic quickly
as technology and prices shift. We recommend that DECC encourage
the development of the offshore shale gas industry in the UK,
working with HM Treasury to explore the impacts of tax breaks
to the sector.
Gas Pipelines Transmission Networks
48. National Grid Gas (NGG)owner and operator
of the national gas transmission system throughout Great Britain
and the Isle of Grain (Kent Coast) LNG import facilitysays
there are likely to be technical challenges surrounding the transmission
of shale gas, "in particular the UK requirements for gas
quality and for [network] entry capacity [requirements]".
SSE (formerly Scottish and Southern) stated that the UK's "existing
gas distribution work, which is one of the most developed in the
world" could offset the higher production cost of shale gas.
Chatham House's Professor Paul Stevens pointed out that access
to the gas grid in the US is based upon "common carriage",
which means "any gas supplier can gain access to the grid
even if it is already operating at full capacity".
Whereas, in Europe, access is based upon "third part[y] access",
which means if the system is operating at full capacity "there
is no access unless dedicated new pipelines are built".
49. Scotia Gas Networks (SGN) is the UK's second
largest gas distribution company, with 5.7 million customers and
74,000 km of gas mains.
It believed that as shale gas wells will be distributed over a
wide area across the UK, they were "likely to need large
numbers of smaller scale connections to gas distribution networks
than typical gas wells".
However, SGN also noted that "the [already] large scale and
wide coverage of the gas distribution network could [
the speed at which shale wells can connect to the system".According
to Shell, shale gas was likely to meet regional and national market
demands in the first instance, as rapid growth in unconventional
gas production was "likely to require new investment in European
gas transport infrastructure" to facilitate pan-European
50. However, it is interesting to note the potential
option to generate electricity on site at the shale well. An example
of this is Cuadrilla's Elswick site, located near Blackpool, which
we visited in March. The Elswick site was commissioned in July
1996, and is a natural gas to electric generation power plant,
which means the power plant sits on top of the gas formation,
negating the need for gas transmission (sometimes referred to
It has been producing natural gas and generating electricity since
1998, and originally produced 1MW of power.102
51. The Minister told us he thought it was more
likely that shale gas would be extracted and used for generating
electricity on site than transported through pipelines: "I
think Cuadrilla's interest has been their closeness to the electricity
grid rather than their closeness to the gas grid".
As well as being input directly into the grid, the Minister suggested
to us that electricity generated from shale gas could "be
linked into a renewable resource [such as wind generated electricity]
and, therefore you have the gas that is available to generate
the electricity when the renewable resource is not there".
52. During our recent visit to the US, we met
with the Mayor of Fort Worth in Texas. There, the shale gas industry
began by exploring in rural areas, but then encroached upon the
city itself as it had identified "sweet spots" where
the gas could be more easily extracted. "Sweet spots"
were described by Nigel Smith of the BGS as "places where
you get higher productivity".
The Mayor told us that that pipelineswhich transport the
extracted shale to compressor stations before it is injected into
the gas mainshad become a major issue, and one they wished
they had dealt with at the outset. Each operator could have their
own set of pipelines, leading to multiple sets across the city.
They acknowledged that a lot of unnecessary duplication could
have been avoided if companies had been made to work together
and share pipelines.
53. There is a suite of environmental legislation,
including Environmental Impact Assessment (EIA) that is applicable
to pipelines for the onshore oil and gas industry in England,
Scotland and Wales. The aim of EIAs is to determine the likely
effects of new developments on the environment, and ensure these
effects are taken into account before the development is allowed
to go ahead. The Town and County Planning (Environmental Impact
Assessment) (England and Wales) Regulations 1999 and the Environmental
Impact Assessment (Scotland) Regulations 1999 require an EIA to
be undertaken for "pipelines for the transport of gas [
and a length of more than 40 kilometres". For smaller gas
pipeline projects, an EIA is only required "if the development
is likely to have a significant effect on the environment"
as determined by the local authority.
54. Planning for any new gas transport infrastructure
required to exploit shale gas should take into account the opportunity
to minimise disruption and costs by sharing pipelines between
different companies operating near to each other. We recommend
that the Government consider amending the Town and County Planning
(Environmental Impact Assessment) (England and Wales) Regulations
1999 to require Environmental Impact Assessments for smaller gas
pipeline projects, with the aim of avoiding unnecessary duplication
36 Ev 71 (BGS) Back
See Box 1, p 13 Back
Q 324 Back
US EIA, World Shale Gas Resources: An Initial Assessment of
14 Regions outside the US, April 2011 Back
See Box 1 p 13 Back
Ev 92 (GSoL) Back
Q 3 Back
Namurian Stage rock containing organic matter from 313-326 million
years ago. Back
Jurassic Stage rock containing organic matter from 145-199 million
years ago. Back
Ev 71 (BGS) Back
Ev 78 (Cuadrilla) Back
Ev 71 (BGS) Back
Q 17 Back
Q 178 Back
Q 279 Back
Ev 78 (Cuadrilla) Back
Ev 78 (Cuadrilla) Back
Q 118 Back
Q 121 Back
Q 122 Back
Ev 75 (IGas) Back
Ev 75 (IGas) Back
Ev 75 (IGas) Back
US Department of State, Global Shale Gas Initiative (GSGI),
May 2011, www.state.gov/s/ciea/gsgi/index.htm Back
"Unconventional Gas may form Majority of U.S. Supplies",
Natural Gas for Europe, 19 November 2010, http://naturalgasforeurope.com/?p=5365 Back
Ken Morgan, "Shale Gas-the Game Changer", TCU Energy
Institute, www.zeitenergy.com/presos/Morgan.pdf Back
"About Schlumberger", Schlumberger, www.slb.com/about.aspx Back
"Schlumberger COO: Current Shale Methods Won't Work Overseas",
Natural Gas for America, 23 February 2011, http://naturalgasforamerica.com/?p=2006 Back
"Schlumberger Chief Say Shale Gas in Europe Faces Challenges",
Natural Gas for Europe, 13 October 2010, http://naturalgasforeurope.com/?p=4270 Back
Q 163 Back
Q 280 Back
Ev 66 (DECC) Back
Ev w19 (Shell) Back
Ev w24 (Chatham House) Back
Ev w19 (Shell) Back
Q 190 Back
Ex w40 (Exxon) Back
Ev w40 (Exxon) Back
Florence Gény, "Can Unconventional Gas be a Game Changer
in European Markets?", OIES, December 2010 Back
Ev 57 (DECC) Back
"Debate over shale gas fires up", Financial Times,
10 October 2010 Back
Paul Stevens, "The 'Shale Gas Revolution': Hype and Reality",
Chatham House, September 2010, p vi Back
Ev 78 (Cuadrilla) Back
Ev w13 (Ofgem) Back
DECC, Digest of UK Energy Statistics 2010,Chapter 4 p 100 Back
Morgan Downey, Oil 101, Wooden Table Press, 2009, p 176 Back
Ev 71 (BGS) Back
Ev 86 (Tyndall) Back
Ev 92 (GSoL) Back
Q 63 Back
Ev 71 (BGS) Back
Q 37 [Smith] Back
Q 44 Back
Q 45 Back
Q 158 Back
Q 281 Back
Q 281 Back
Q 283 Back
Ev w7 (NG) Back
Ev w9 (SSE) Back
Ev w24 (Chatham) Back
Ev w24 (Chatham) Back
Ev w11 (SGN) Back
Ev w11 (SGN) Back
Ev w11 (SGN) Back
Ev w19 (Shell) Back
"Elswick Gas Field", Warwick Energy, www.warwickenergy.com/oandg/OAGelswick.htm Back
Q 316 Back
Q 317 Back
Q 20 [Smith] Back
"Environmental legislation applicable to the onshore hydrocarbon
industry (England, Scotland and Wales)-4. Environmental Impact
Assessment", DECC Oil and Gas, www.og.decc.gov.uk Back