Subsurface Structural Trap

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Subsurface Structural Trap
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Todays Activity

• talk about how we find oil
• simulation to plan the drilling of a well

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but before we start ..
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Who Works in Petroleum Engineering?

• people who
• enjoy math, science, and computers
• interested in the earth, resource development
• enjoy personal interactions with clients and
  vendors
• also
• enjoy travel (energy business is international)
• like to work outdoors (wilderness areas, well
  site, oil field, environmental clean-up site)

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Petroleum Geology

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Fundamentals of Petroleum Exploration

• reservoir rock
• trap
• source rock
• seal
• migration of oil

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Oil is stored pores between the grains in
sandstones and other "reservoir" rocks
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Rivers Transport Sand and Mud
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Core showing channel sands
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Making a Structural Trap
Originally Horizontal Beds .
Cedar Mesa Sandstone, SE Utah
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sometimes get folded

• topography accentuates strike and dip

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Folds and Faults make TRAPS
- faults represent brittle rock deformation
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Subsurface Geology(how do we see underground?)

• core
• seismic
• logs

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Fundamentals of Petroleum Exploration

• source rock
• migration of oil
• reservoir rock
• trap

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How do we see below the surface?
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Seismic
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Casper Arch Thrust, Central Wyoming
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Seismic Acquisition and Processing
4-D Seismic and Reservoir Modeling
4-D Reservoir Monitoring
4-D Seismic
Subsalt Imaging
Base-1983
Update-1995
Difference
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Casper Arch Thrust, Central Wyoming
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Fundamentals of Petroleum Accumulation
Reservoir Rock
Source Rock
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Putting it all together ..
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Original Horizontal Layers
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Mountain Building - Compression
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Build a structural trap
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Deformed Reservoir
Seal
Reservoir
Source
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Migration of Oil
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driven by buoyancy
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Trapped Oil
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Will folding in one direction be an effective
trap?
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Plate Tectonics Deforms/Folds Rocks
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Really need folding in two directions
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And that dome needs to be buried covered with a
seal!
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Available Data

• Interpreted Seismic Lines
• needed to determine if you have a trap
• Well-log Lithology
• needed for determining whether you have a
  reservoir rock (sandstone) and a seal
• determine potential source rock (shale)
• Geochemical Analysis
• determine if a potential source rock has
  generated oil

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Instructions

• divide into teams of 3 or 4 explorationists
• your budget is 330,000
• purchase data
• analyze data to choose a spot to drill

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Prices

• Seismic Lines
• Line A - 100,000
• Line B - 75,000
• Line C - 75,000
• Well-log Lithology
• Well 1 - 25,000
• Well 2 - 35,000
• Geochemical Analysis
• Well 1 - 5,000
• Well 2 - 5,000

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Seismic Line A
Sandstone
Limestone
Shale
Sandstone
Shale
Sandstone
Shale
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Seismic Line B
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Seismic Line C
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Combining Seismic Lines for 3d
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Seismic Line A - Solution
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Seismic Line B
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Seismic Line C No Trap!