Plankton, the Fuel of War:
The Origin and Development of Iraqi Oil
Lecture Outline
• Introduction
• Geologic development
of Iraq and oil formation
• Tectonic history
• Sedimentation
history
• Human history of oil
production in Iraq
• Current trends in oil and
gas use
This ad for the Chevron-Texaco 1936
marketing merger featured a
processing plant built in Bahrain
The Arabian Peninsula is Home to
the World’s Largest Oil Reserves
Middle
Eastern
Political
Boundaries
and the
Arabian
Peninsula
Folds in Sedimentary Layers Can Trap Oil
Oil migrates from a source rock into a trap in a reservoir rock
Requirements for Formation of
Oil and Gas Deposits
• Source Rock - sedimentary strata rock rich in organic matter
typically shale or limestone
• Thermal maturation and migration - Source rock is heated to
90 to 150oC to convert organic solids into liquid hydrocarbon (oil
and natural gas)
• Reservoir Rock - Sedimentary rock in which oil accumulates;
must contain abundant pore spaces; typically sandstone or limestone
• Seal Rock - Impermeable sedimentary strata that blocks upward
flow of oil; typically shale or evaporites (salt)
• Trap - Geometric arrangement of reservoir and seal rocks that
cause significant amounts of oil to accumulate in one area
• Timing - Trap must form before thermal maturation and
migration occurs
Plankton in the Arabian Sea
Oil Forms from Plankton Remains
diatom
radiolarian
coccolithophore
foramifera
Tectonic Development of Arabian Peninsula
Paleozoic
255 Ma
• Arabia covered by
Paleo-Tethys Sea
(shallow)
• Shale source rocks
accumulate in Saudi
Arabia
Tectonic Development of Arabian Peninsula
Early Triassic
235 Ma
• Persia rifts from
Arabia
• Arabia inundated
by Tethys Sea
(shallow)
Tectonic Development of Arabian Peninsula
Jurassic
195 Ma
• Arabia
covered by
shallow Seas
• Organic - rich
limestone
source rocks
accumulate
Distribution
of Jurassic
Source
Rocks on
Arabian
Peninsula
From USGS Bull. 2202-E
Tectonic Development of Arabian Peninsula
Cretaceous
95 Ma
• Arabia covered by
shallow Seas, but
Tethys Sea begins
to close
• Limestone and
sandstone
reservoir rocks
accumulate
• Evaporite seal
rocks accumulate
Distribution
of
Cretaceous
Seal Rocks
on Arabian
Peninsula
From USGS Bull. 2202-E
Tectonic Development of Arabian Peninsula
Early Tertiary
35 Ma
• Arabia collides
with Persia and
Asia
• Zagros Mountains
begin forming (+
Alps through
Himalaya)
• Anticline traps
formed
• Oil migrates from
source rocks to
reservoir rocks
and accumulates
in traps
Tectonic Development of Arabian Peninsula
Overly
Deformed
and Uplifted
Rocks
Insufficient
Accumulation of
Sedimentary Rocks
Oil was first discovered in the Middle East by George
Reynolds (left) in 1908, working for a British Company
History of Middle Eastern Oil
Development and Production
• Pre - WWI
• 1908 - Oil discovered by British Interests in
Persia (Iran) after 5 - year search.
• Ottoman Empire (Iraq, Saudi Arabia) mostly
unexplored for oil
• Post - WWI
• Oil recognized by Europeans and U.S. as vital
to national security
• Ottoman Empire dissolved
• Oil discovered near Kirkuk in 1927
• Production volume split equally between
Britain, France and U.S. by agreement
• 1938, oil discovered in Kuwait and Saudi
Arabia
History of Iraqi Oil Development and
Production
Two Stages
• 1925-1961
• Iraqi Petroleum
Company, post
WWI, moderate
development,
most profits
taken abroad
(Britain)
• 1968 - Present
From Graham, 2002
U.S. consumes 20 million bbl/day, 7 billion bbl/year
• Iraqi National Oil
Company, rapid
development,
profits kept in
Iraq
Iraqi Oil
Fields
Two main
groups
• Basrah
area in
southeast
• Kirkuk
area in
north
Iraqi Oil Exports
• To the U.S.
• 800,000 bbl/day
U.S. Imports of Iraqi Oil
• 8.5% of total U.S.
imports
• 32% of Iraqi exports
• To other countries
• 1.5 million bbl/day to
France, China and
Russia
• 200,000 to 400,000
bbl/day smuggled to
neighboring states
• Erratic Production
Rates
From Graham, 2002
Iraqi Oil Potential
Estimated
Reserves
• Proven reserves
• 112 (EIA, 2002) to 142
(Ibrahim, 1996) billion
barrels
• Undiscovered
reserves
• 45 (USGS) to 220
(EIA) billion barrels
From Graham, 2002
U.S. Oil Consumption Will Outpace
Production
• Based on
trends over
past ten years
• U.S.
consumption
will increase
by 6 million
bbl per day
• U.S.
production
will decrease
by 1.5 million
bbl per day
After Graham, 2002
Does Cheap
Gas Fuel
Increased
Consumption?
Oil and Gas Prices, 1920-1995
Where the U.S. Gets Its Oil Imports
Global Oil Reserves
Persian Gulf Oil
Conclusions
• Fortuitous geologic history gave Iraq
enormous oil reserves
• U.S. and global oil consumption will increase
while production declines
• Iraq will play vital role in global economy