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Introduction
Energyfiles forecasts are, of course, based on many
assumptions. All forecasts assume a generally stable global political
environment, unrestricted (except by economic conditions) worldwide
growth in oil and gas demand to their peaks and continuing steady
improvements in technology.
Although in truth the environment is unlikely to be
stable in all local regions, average regional stability is more likely
than not. Production, reserves and recoverable
resources for each country are independently assessed based on global
data and expert judgement.
Geographic scope
At the last count there were 231 independent countries
(including semi-independent territories). 96 of these currently produce
oil, condensate, natural gas liquids and/or gas at rates of over 1000
bbls equivalent per day.
Several further countries have produced oil in
the past at rates close to or above 1000 bbls/day but are now producing
either no oil and/or gas or very little. Others are believed to have the
potential to produce oil and/or gas at rates of over 1000 bbls/day but
have not yet done so. For forecasting purposes all countries have been
included in the analysis.
Fluid scope
All forms of oil and gas are included in global data
sets.
Any hydrocarbon production from wells that remains
naturally a liquid at surface temperatures and pressures is included as
oil even if it has to be artificially recovered from gas. These are
called conventional oils. Thus natural gas liquids (NGLs) are included
as oil, even though they must be refined from gas, whilst liquefied
natural gas (LNG) and gas-to-liquids (GTLs) are not included as oil
since they have to be stored in pressurized bottles and/or at low
temperatures or have to be converted. They are included in the gas
figures (volumes prior to conversion).
Most extra-heavy oils (unconventional oils) that are
extractable under a different economic model and time scale to
conventional oils are not directly included in the remaining reserves
and resources numbers. However bitumens (specifically those contained in
the oil (tar) sand belt of Canada and extra-heavy oils located in the
Orinoco Belt of Venezuela, where production may be converted by refining
into liquid synthetic oil (synfuel) are individually analysed and
included in global production and cumulative production figures.
Unconventional oils such as GTLs, coal-to-liquids (CTLs), oil from
shales and biofuels are considered separately.
All gas production from conventional oil fields,
including from tight gas reservoirs that has been marketed as free gas
or LNG has been included. Production of flared and re-injected gas has
not been included directly. Unconventional gases such as Coal Bed
Methane (CBM)are considered separately.
Theory
It has been shown both theoretically and empirically that
oil and gas production, freely extracted from a sedimentary basin, rises
to a peak at a roughly steady rate as new fields come onstream then
begins to decline at a roughly steady hyperbolic rate as the first
fields begin to deplete and the last few are unable to make up the
difference.
Oil production has a relatively sharp peak whilst, in the
past, gas production has tended to form a plateau due to its different
marketing system. Pricing adjustments, technology and the use of earlier
infrastructure that subsidises later output, all act to stretch decline
out creating a skewed distribution.
Production capacity
Production capacity is the volume of oil and/or gas a
field, basin, country, region or the world can produce in a given time
period. Most countries try to produce as much as they can as quickly as
possible. OPEC countries have artificially restricted oil production to
conserve resources and prop up and stabilise the oil price. The speed at
which new oil is extracted is increasing rapidly under the influence of
new and improved technologies.
Resources and reserves
Here definitions are as follows:
Resources - total amount (of oil & gas) left in place
in the world
Recoverable resources - part that can be recovered
with realistically available technology/economics
Reserves - part that is discovered & recoverable
Cumulative production - reserves already produced
Remaining reserves (most likely) - discovered
reserves that will eventually be produced but have not yet been
Yet-to-find resources (most likely) - recoverable
resources that will be discovered
Future cumulative – all reserves that have and will
be produced to a specific year (in general we use 2145)
Cumulative production is the total volume of oil or gas
up to a given year that has been produced. Numbers for cumulative
production are taken from the source believed to be most reliable. In
most cases this is directly from government figures although
uncertainties arise from different modes of measurement, inclusion of
different fluids and mixed conversions. All uncertainties have been
minimised wherever possible.
Although reserves must always be economic for them to be
recovered estimated remaining reserves are taken to be the most likely
amount of oil or gas that has been discovered but not yet produced, and
will be recovered under economic conditions that could exist in the
future if the world remained a stable, comfortable place to live in. If
the world becomes unstable then all economic forecasts, and indeed most
other forecasts become meaningless.
There will always be additional remaining reserves that
will be recovered but such volumes will be insignificant in world terms
and recovered far in the future. There are large uncertainties in
remaining reserves due to conservative, optimistic and poor reporting by
many countries. In a market environment (especially in the USA) proven
reserves are artificially constrained by economics. Proven reserves are
not used in the analysis. Most likely reserves numbers have been
independently assessed by Energyfiles.
Yet -to find resources are estimated here and are
coincident with the views of most major oil companies. However some
analysts believe that the world’s yet-to-find totals are much greater.
The United States Geological Survey (USGS) in particular, report large
oil values, with most of this extra oil available in remote regions with
none or little current production.
In the view of Energyfiles companies
have struggled to find global reserves outside traditional producing
regions for good geological reasons. They have explored almost
everywhere that it is possible to explore. Deep waters and neglected
regions in OPEC and former communist countries provide much of the
yet-to-find oil and gas resources included in the analyses with
additional gas available in polar regions.
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