NATURAL

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NATURAL GAS
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What is it?
Waste product produced by bacteria and enzymes
that breakdown organic matterMostly methane
(CH4) with a small amount of other
hydrocarbonsCan be associated with both oil and
coal produced by breakingdown bothAlso
associated with swamps, rice fields, termites,
and cattle
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Characteristics
Good - 1) Burns cleanly, with very few pollutants
2) Easier to use in fuel cell (more
efficient) 3) Large supplies worldwide Bad - 1)
Hard to transport and store 2) Leaks result in
greenhouse gas emissions
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Types

• Dry natural gas - consists of only gaseous
  component mostly methane, with butane and
  propane
• Natural gas liquids - the non-gaseous, organic
  components of natural gas heavier
  hydrocarbons such as pentane
• Wet natural gas - natural gas that is mixed with
  non-organic substances such as water vapor,
  carbon dioxide, and nitrogen

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Consumption
U.S.
World
Use Percent Residential 21.7 Commercial 14.0 I
ndustrial 31.8 Electricity Generation 25.0 Automo
biles 0.1 Pipeline 2.8 Lease and plant 4.6
eia.doe.gov, 2004 data
Data from the Dept. of Energy,
Most natural gas in U.S. is used for industrial
processes. Residential usage accounts for about
1/4 of the total. The U.S. uses the most natural
gas in the world
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Production
Produced with wells, just like oilUnlike oil,
natural gas does not cling to rock rock
permeabilityvery importantIn stable rock
environments, can increase flow by fracturingthe
rock with dynamite or waterCan use pumps and
injector wells to increase flow throughrock
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Natural gas - recovery
Gas reserves usually associated with oil or coal
deposits
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Processing
Natural gas normally requires very little
processing before itcan be moved to market ? put
it directly into pipelineSubsea completion -
some gas wells are fed into pipelinedirectly at
the ocean floor saves tremendous amount of
moneyin deepwater environment Occasionally,
need to remove excess water and sulfur can
bedone on nearby platformBefore it is sold
commercially, need to put in mercaptans
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U.S. Production
Production peaked in 1973Production bottomed
outin the mid 1980s price surge increased
demand afterthat
We currently produce almost 20 TCF of natural gas
per year To meet consumption needs, we import
from Canada and MexicoLack of infrastructure to
Alaska means that we pump 3 TCFback into the
ground each year
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Gas Reserves
Data from Hubbert Center, http//www.oilcrisis.com
/gas/
This data is 8 years old. Current consumption is
26 TCF inNorth America and 90 TCF
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Coal Bed Methane
This is natural gas that is trapped within the
coal seamused to be the reason that coal
miners took canaries withthem into
minePotentially huge reserves of this
Easier to drill than other wells, as coal is
closer to surface cheaperWater that must be
removed first is saline disposal
problemEstimated at 700 TCF in U.S. 100 TCF
developable now
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Methane Hydrates
Methane locked in an ice lattice foundmost
often on ocean floorVery little known about
these deposits- Unknown how they form- Unknown
how stable they are- Unknown how to produce
reserves- Unknown how much there is in the
world Potentially, more than twice the amount of
carbon in methanehydrate deposits than all other
fossil fuels combined
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Outlook
Even with our usage, we have been able to add to
reservesrecently if have to rely on
conventional sources, will run out in15-20
years If coal bed methane proves feasible, could
add many years to this outlook If methane
hydrates prove producible and as plentiful as
thought,natural gas could be fossil fuel of
futureEffect on global warming unknown