Glossary of Terms
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glossary
Associated Gas
Gas that is found along with oil. The gas is usually wetter (see
wet gas).
BGS
Casing String
Well casing is installed in several stages of "strings",
subsequent strings inside previous ones. Each casing string is made
up of several segments jointed together. The casings are cemented
in place and should withstand the pressure inside the well
bore.
CBM
Coal Bed Methane; also CMM, Coal Mine methane; CSG, Coal Seam
Gas. Natural gas that is found in coal seams. Previously in the
coal mining industry, this gas was vented or flared, as it was
poisonous to miners. Hydraulic fracturing (fracking)
may be used to free up gas trapped in coal, however this is done
solely with water and sometimes proppant.
CCS
Carbon Capture and Storage - technologies to capture emissions
from fossil-fuel power plans and store them away from the
atmosphere. See IGEM's research on CCS.
Coastal Oil and Gas
CSG
Coal Seam Gasification - injection of hot air and steam into
sub-surface coal to produce hydrogen, methane and carbon
monoxide.
Cuadrilla
Cuadrilla
are the first shale drillers in the UK
DECC
Department for
Energy and Climate Change. The government body that decides on
the UK's Energy policy. Among other things, they evaluate the UK's
potential for different forms of energy, produce information for
parliament and the public about different forms of energy and are
in charge of Oil and Gas Licencing.
EA
Environment Agency -
the government agency for England and Wales that implements the
DECC's policies and ensuring Oil and Gas companies do not pollute
the environment. They must issue a permit to any company that plans
to inject fluid into groundwater, or "mobilise natural substances
that could then cause pollution"(795), e.g. a coal spoil heap from
which chemicals could leak into watercourses, or if fracking were
to displace methane from the rocks into groundwater.
They must inspect the area before drilling to determine whether
it needs a permit, and if so, whether they will issue one. They
will be monitoring the flowback water from fracking in Lancashire
and are looking at options for monitoring air for fugitive
emissions. In Scotland the analogous agency is SEPA.
ECCC
Energy and Climate Change Committee. A committee of MPs chaired
by Tim Yeo MP who investigated whether Shale Gas was suitable for
the UK. They concluded that it was, and made recommendations to the
relevant bodies involved. Their comprehensive report is available
here (volume 1) and here (volume 2).
EIA
EPA
Environmental Protection Agency - a US federal body similar to
the EA and SEPA in the UK. Currently conducting an in-depth study
with the GWPC (Ground Water Protection Committee) into whether
fracking is contaminating groundwater aquifers.
Field
A deposit of gas (or oil).
Flowback Water
Water that flows back out of the well in the weeks following
fracking. After the rate drops to a steady level, this is called
Produced Water. Flowback water is of environmental concern, as not
only does it contain the chemicals put in for fracking, but also
chemicals from the rock (such as benzene and mineral salts) and
NORM.
Fracking
Also Fracing, Hydrofracking, Hydraulic Fracturing. See Fracking
Fugitive Emissions
Natural Gas released to the air between the well cap and the end
user, usually through leaks or through venting of pressure
build-ups, or venting prior to production.
Gas Hydrates
Gas that is trapped in an ice-like structure. Found in
permafrost and under the polar ice caps. Disassociates at higher
temperatures. Read more...
The Howarth Report
A report by Professor Robert Howarth of Cornell
University in the USA. It suggests that Shale Gas' greenhouse gas
advantage over coal may be much less than predicted due to the
presence of increased Fugitive Emissions (from gas released before
production and methane in flowback water).
HSE
Health and Safety
Executive. Responsible for the safe operation of industrial
sites and appliances in the UK.
IGEM
LNG
Liquefied Natural Gas. Since gas is typically a high volume, low
value product, it becomes very expensive to transport it long
distances. Pipelines must be built, which are more or less
permanent and inflexible. Natural gas can be liquefied and stored
under pressure in containers. This can be transported much more
easily, especially inter-continentally.
Approximately 9% of the energy value of the gas must be used
simply to power the liquefaction process, with a further 6-9% used
in transport. However, Liquefaction is more cost effective than
pipelines for distances over 2,500 miles (4,000 km).
Read IGEM's research on LNG in the UK Marketplace
Mature Gas
Gas that has a high proportion of methane.
Methane
The main component of Natural Gas, composing approximately 90%.
Its chemical formula is CH4 and it is colourless, odourless and
lighter than air. More
Natural Gas
Gas extracted from underground deposits, formed by the
decomposition of prehistoric organic matter. It is mostly methane,
but also contains propane, butane, and other impurities which may
need to be removed before the gas is transported due to HSE
standards. It produces the least carbon dioxide when burned of any
fuel apart from Hydrogen.
Non-associated Gas
Gas found without oil nearby. It is usually more mature, with a
higher proportion of methane.
NORM
Naturally Occuring Radioactive Material. Trace amounts of
radioactive elements have been found in flowback water. In no case
so far have these been found to be a danger to human health or the
environment.
OFGEM
Oil and Gas Licensing
Designates areas of land in the UK to Oil and Gas companies to
prospect for Oil and Gas (giving them exclusive rights to the
area). This takes place in rounds, and we are currently awaiting
the 14th round of oil and gas licensing. However, in order to drill
a well, the company must apply for planning permission from the
local council, pay the landowner and get a permit, if necessary,
from the Environment Agency.
Onshore
Wells drilled on land, as opposed to offshore. In order to
access an oil or gas field under the sea, company may drill onshore
and then drill horizontally out to sea; this is often more cost
effective and safer than drilling offshore.
Play
An area of gas rich shale broadly similar in quality. Plays are
much larger than fields, and there is also less gas per area, since
it is incorporated in the rock. A play can span tens of thousands
of square kilometres.
Produced Water
Water that comes from the well along with the gas, containing
chemical contaminants from the rock. This is typical for all
natural gas wells. Flow rates of produced water are in the order of
a few thousand litres a day.
Proppant
Ceramic beads or sand that are suspended in fracking fluid.
These migrate into the fractures and prop them open when the
fracking fluid is removed, so that gas can flow out of the rock
more easily.
SEPA
Tight Gas
Gas that is trapped in very impermeable rock or sandstone. It
can be extracted by fracking
"The Tyndall Report"
A report by the Tyndall Centre, a multi-insitutional centre for
climate change research, commissioned by the Cooperative. It
concludes that Shale Gas production should be postponed until
further research is available as to its effects on the environment,
citing evidence of industrial accidents and anecdotal evidence of
water contamination from fracking.
Unconventionals
Sources of natural gas that are not the conventional gas fields.
This includes shale gas, CBM, CSG, tight sand gas and gas hydrates.
Unconventionals are set to be a major player in international gas
markets as technology makes their extraction viable and a decline
in conventional reserves drives gas prices up.
Wet Gas
Gas with a higher proportion of propane, butane and other
compounds. Usually associated (see associated gas)
WWF-UK
World Wide Fund
for Nature UK. The main environmentalist opponent to shale gas
in the UK. Their main concerns are the lifecycle greenhouse gas
emissions and contamination of air and water. Interview HERE
