Please . . . .
Vagabond Ventures Oil Group
Searches For Fossil Fuels
Winter Session 2013
The
Outline
Oil
& Course
Gas Exploration
The Basics:
Week 1: Geology & History of Hydrocarbons
Week 2: Oil & Gas Exploration
Week 3: Petroleum Engineering
The Adventure:
Week 4: ‘Vagabond Group’ proposes 2 prospects
Week 5: ‘Vagabond Group’ plans production
Week 6: the Payout?!
A black-gold millionaire or dry hole hobo?
Oil & Gas Exploration
Requirements
for success
- Requirements for success
- Exploration processes
1) Source
2) Reservoir
3) Migration Path
4) Trap
Requirements for success
reservoir rock
(sandstone)
where gas/oil are ‘stored’
- porous
- permeable
surface
Top of mature (generating) source rock
source rock (shale)
where the organic material is ‘cooked’
- organic rich
- buried quickly
- compressed/heated
Requirements for success
reservoir rock
(sandstone)
where gas/oil are ‘stored’
- porous
- permeable
source rock (shale)
where the organic material is ‘cooked’
- organic rich
- buried quickly
- compressed/heated
Requirements for success
reservoir rock
(sandstone)
source rock (shale)
without a TRAP . . .
the oil & gas escapes!
Requirements for success
reservoir rock
(sandstone)
TRAP = barrier to migration
- anticline
- thrust fault
- normal fault
- salt dome
rock (shale)
- faciessource
change
without a- TRAPS
TRAP . . .
the oil & gas escapes!
Requirements for success - TRAPS
Compressional forces can cause rock layers to
BEND & FOLD . . . .
Anticline
impermeable
oil/gas
sandstone
shale
Requirements for success - TRAPS
Compressional forces can cause rock layers to
FRACTURE . . . .
Thrust Fault
impermeable
oil/gas
sandstone
oil/gas
shale
impermeable fault plane
Requirements for success - TRAPS
Extensional forces can cause rock layers to
STRETCH & FRACTURE . . . .
Normal Fault
impermeable
oil/gas
sandstone
shale
impermeable fault plane
Requirements for success - TRAPS
Intrusions into layered rocks . . .
Salt Dome
oil/gas
Requirements for success - TRAPS
Rock Properties within a rock layer
can be different . . . .
Facies Change
former river channel
Imbedded in sedimentary rock layers
Oil Exploration
Exploration
processes
- Requirements for success
1) Source
2) Reservoir
3) Migration Path
4) Trap
- Exploration processes
- Geology
- Geophysics
- ‘Land’ work
Exploration processes
Geology
Geophysics
?
What’s the difference?
Land Work
Engineering
Exploration processes
from last week . . .
Geology
Geophysics
What’s the difference?
Exploration processes
Geology
‘geo’ = earth ‘logy ’= study
. . . uses field work and rock analysis to study the
composition, processes, & history of the earth
Geophysics
‘geo’ = earth
Brunton
compass
‘physics’
. . . uses physics and mathematics to
evaluate the internal structure of earth
hand lens
Geoscience
Exploration processes
Scientific Tools
THE SCIENTIFIC TOOLS
- well logs
- subsurface imaging
- contour maps
USE THE TOOLS TO FIND OIL & GAS
- look for TRAPS
- look for RESERVOIRS
Scientific Tools
next week
- well logs
- subsurface imaging . . . Seismic Data
- contour maps
Subsurface
Scientific Imaging
Tools
This is a ‘Seismic Section’, similar to a X-section
What is this wiggle trace?
Subsurface Imaging
This
is a ‘Seismic
similar
to aofX-section
Reflections
from Section’,
the top and
bottom
rock layers
How do we acquire these reflections?
What is this wiggle trace?
The Seismic Method
energy source
receiver
surface
(land or water)
depth
?
rock layer
reflection point
Travel time (sec)/2 X velocity (ft/sec) = DEPTH (ft)
The Seismic Trace
Seismic Trace
source
receiver
surface
rock
layers
Seismic
Trace
theThe
2-D
Seismic
Line
energy
source
Depth (ft)
receivers
the 2-D Seismic Line
Acquisition – on Land
listening devices . . .
Acquisition – on Land
What listening
about an devices
energy source??
...
Acquisition – on Land
energy
What about
source
an-energy
Vibroseis
source??
truck
Marine Acquisition
Acquisition
– on Land
energy source - Vibroseis truck
sea surface
sea floor
Marine Acquisition
Acquisition
on Land
listening devices . . .
energy source . . .
Boat
cable with hydrophones
airgun
Marine Acquisition
Acquisition
on Land
listening devices . . .
energy source . . .
Boat
cable with hydrophones
airgun
Seismic
Survey
Layout
– 2D
Marine
Acquisition
Acquisition
on Land
listening devices . . .
energy source . . .
Boat
Seismic Survey Layout – 2D
line spacing is usually ¼ - ½ mile apart
Grid ofSurvey
2-D Seismic
Seismic
LayoutLines
– 2D
line spacing is usually ¼ - ½ mile apart
Grid of 2-D Seismic Lines
each seismic line becomes
part of the data grid
using the grid
we identify rock layers
& make ‘contour’ plots
of each layer
Grid ofPlot
2-Dfrom
Seismic
Lines
Contour
a 2-D
Survey
each seismic line becomes
part of the data grid
using the grid
we identify rock layers
& make ‘contour’ plots
of each layer
Contour Plot from a 2-D Survey
We use these plots to
find possible oil traps
BUT . . . . .
With large spaces
between the lines,
the contours could
be wrong!
The trap could be bigger . . . or smaller!!
Contour
3-DPlot
Seismic
fromSurveys
a 2-D Survey
We use these plots to
find possible oil traps
BUT . . . . .
With large spaces
between the lines,
the contours could
be wrong!
The trap could be bigger . . . or smaller!!
3-D Seismic Surveys
2-D Survey versus 3-D Survey
3-D Seismic Surveys
listening devices . . .
Steering devices
3-D Seismic Surveys
listening devices . . . reels of hydrophone cables
3-D Seismic Surveys
listening devices . . . reels of hydrophone cables
3-D Seismic Surveys
energy
listening
source
devices . . .
boat
3-D Seismic Surveys
energy source : airgun array
boat
3-D Seismic Surveys
energy source : airgun array . . . deploying an airgun
3-D Seismic Surveys
energy source : airgun array . . . deploying an airgun
It’s Now
a
3-D
Seismic
Cube
Remember
the
2-D
Seismic
3-D Seismic Surveys Grid?
Vertical slices
Horizontal slices
geoscience
applications
It’s Now& aengineering
3-D Seismic
Cube
water layer
salt layer
reservoir layer
possible oil/gas
source rock layer
2-D vs 3-D seismic acquisition in
the Gulf of Mexico
No. traces
1983
1995
Exploration Processes
THE SCIENTIFIC TOOLS
- well logs (next week)
- look for TRAPS:
- subsurface imaging
- anticlines
- contour maps
Finding
and &Gas
- fault trapsOil
– normal
thrust
- salt domes
USE THE TOOLS TO FIND OIL & GAS
- change in rock type (facies)
- look for TRAPS
- look for RESERVOIRS:
look
for
RESERVOIRS
- attribute analysis
Finding Oil and Gas
- look for TRAPS:
- anticlines
- fault traps – normal & thrust
- salt domes
- change in rock type (facies)
Finding Oil and Gas
Anticlines - tilted & folded rocks
How does this look on seismic?
Finding Oil and Gas
Anticline - tilted & folded rocks
Vertical Slice from 3-D Cube
Finding Oil and Gas
- looking for TRAPS:
- anticlines
- fault traps – normal & thrust
- salt domes
- change in rock type (facies)
Finding Oil and Gas
FAULTS - Rock Layers that are broken
sandstone
shale
normal
fault
a;
How does this look on seismic?
Finding Oil and Gas
Normal Fault
2-D Seimic Line
from shallow water
Gulf of Mexico
Finding Oil and Gas
numerous rock layers
numerous faults
several anticlines
Finding Oil and Gas
- looking for TRAPS:
- anticlines
- fault traps – normal & thrust
- salt domes
- change in rock type (facies)
Finding Oil and Gas
FAULTS - Rock Layers that are broken
Possible oil/gas traps
Thrust
Fault
Let’s look at an example . . .
Finding Oil
example of mountain thrust faulting. . . .
Mounatins
Foothills
How does this look on seismic?
Finding Oil
Thrust Fault
http://www.efieldexploration.com/edsuploads/NonSeismicMethods/Non-Seismic.pdf
Finding Oil and Gas
- looking for TRAPS:
- anticlines
- fault traps – normal & thrust
- salt domes
- change in rock type (facies)
Finding Oil and Gas
Salt Dome - Intrusion into layered rocks
Salt Dome
How does this look on seismic?
Finding Oil and Gas
Salt Dome
2-D Seismic Line
from shallow water
Gulf of Mexico
Finding Oil & Gas
Some Faults
Bright Spots?
Salt Intrusion
possible drill Location
salt intrusion
Finding Oil
Oil well
Salt Dome
Vertical Slice from 3-D Cube
In deep water
Gulf
salt dome
trap? of Mexico
oil in these layers
possible oil reservoir
Finding Oil and Gas
- looking for TRAPS:
- anticlines
- fault traps – normal & thrust
- salt domes
- change in rock type (facies change)
Finding Oil and Gas
Change in rock type – River Channel
former river channel
How
does inthis
look on
seismic?
Imbedded
sedimentary
rock
layers
Finding Oil and Gas
3-D horizontal
River
Channel
slice
from Sarawak, Malaysia
XX
From Rijks & Jauffred
Finding Oil and Gas
- looking for TRAPS:
- anticlines
- fault traps – normal & thrust
- salt domes
- change in rock type (facies)
- looking for RESERVOIRS:
- brights spots
- flat spots
- frequency/phase/intensity changes
Finding Oil and Gas
Bright Spot - high seismic response
gas/oil in rock pore
spaces reflect more
energy than water
high amplitude zone
often high amplitudes
are highlighted in color
bright spot
Finding Oil and Gas
vertical slice from 3-D cube
shallow water Gulf of Mexico
Proposed
wells
Can we find the bright spots?
Finding Oil and Gas
- looking for RESERVOIRS:
- brights spots
- flat spots
- frequency/phase/intensity changes
Finding Oil and Gas
Flat Spot - sag under an anticline
In the rock pore spaces, energy waves travel
more slowly through oil than through water
possible oil/gas
Apparent sag on seismic
OIL
flat spot
Finding Oil and Gas
Do we also have a bright spot?
expanded area from a
vertical slice of a 3-D cube
Can we find the flat spot?
Finding Oil and Gas
- looking for RESERVOIRS:
- brights spots
- flat spots
- frequency/phase/intensity changes
Finding Oil and Gas
3-D data
possible oil-filled river sands!
River Channels
Finding Oil and Gas
3-D data
anticlines
possible
oil/gas
With a 3-D seismic cube
We discover a
Salt dome . . .
We analyze
potential traps . . .
We project well
locations into the
potential reservoir
possible discovery!
Land-Lease
Land-Lease
with proposed location from geoscientists. . .
two
important
factors
.
.
.
- develop a surface map
- determine ownership of
- surface land rights
- sub-surface mineral rights
- identify hazards
- determine timing
- negotiate contracts
Land-Lease
two important factors . . .
1) location: off-shore or on-shore
2) ownership: public or private
example: West Africa
Most countries . . . .
- protect their offshore territories
offshore Angola
where Rocky & I worked
Most countries . . . .
- protect their offshore territories
- subdivide them into ‘blocks’
- lease exploration rights
in each block
offshore Angola
where Rocky & I worked
Most countries . . . .
- protect their offshore territories
- subdivide them into ‘blocks’
- lease exploration rights
in each block
offshore Angola
where Rocky & I worked
A
N
G
O
L
A
Offshore blocks are
usually different shapes
Block 17 started
deep water
exploration &
drilling in
Angola
offshore Angola
where Rocky & I worked
A
N
G
O
L
A
Block 17 started
deep water
exploration &
drilling in
Angola
off-shore
on-shore
Blocks available
in Angola’s
2008 Lease Round
Most countries have
public auctions for
exploration rights
These are called
‘lease sales’ or
‘leasing rounds’
Land-Lease
two important factors . . .
1) location: off-shore or on-shore
2) ownership: public or private
- Different individuals/groups may own
the surface & subsurface rights
- Timing & contracts are negotiated
with all owner-parties
difficult and time consuming!
Oil Exploration
- Requirements for success
- Source
- Reservoir
- Migration Path
- Trap
- Exploration processes
- Geology
- Geophysics
- ‘Land’ work
Oil
Exploration
Exploration processes
- Requirements for success
- Source
- Reservoir
- Geology
Migration Path
Geophysics
- Trap
- Exploration processes
- Geology
- Geophysics
Land Work
Engineering
- ‘Land’ work
Geology
Geophysics
Drilling recommendations &
detailed cost flow chart
Until then . . . . visit our website:
Land Work
Engineering
www.vagabondgeology.com
Petroleum Engineer
REFERENCES
Money in the Ground, John Orban III
Petroleum Geology, Exploration, Drilling and Production, Norman Hyne
Pitfalls in Seismic Intrepretation, Paul Tucker, Howard Yorston
Halliburton/Aramco..... Mr. Frank Kelly, Mr. Mohamed Zeghlache
Schlumberger………….. . Mr. Shabbir Almed. Mr. Jack Caldwell
Texaco ……………………. .. Ms Gail Kahle Butler, Mr. Tako Koning
Tulow Oil ………………….. Mr. Jim Brandon, Mr. Tako Koning
Western Geco Corp…. . Mr. Robin Wrigley. Mr. Bruce Clulow
Geology Rocks!