Well 5 Well 4 Well 3 Well 2 Well 1 Vail et al., 1977b AAPG 1977 reprinted with permission of the AAPG whose permission is required for further use.
Well 5 Well 4 Well 3 Well 2 Well 1 Vail et al., 1977b AAPG 1977 reprinted with permission of the AAPG whose permission is required for further use.
A B C D E F A B C D E F G A B C D E F G A B C D E F H Vail et al., 1977b AAPG 1977 reprinted with permission of the AAPG whose permission is required for further use. Well 5 Well 2 Well 3 Well 4 Well 1
Tim Carr - West Virginia University
Structural Stratigraphic Combination Other 5
Fault (impermeable) Hydrocarbon accumulation in the reservoir rock Top of maturity Oil/water contact (OWC) Migration route Seal Reservoir rock Source rock 6
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Plate Boundaries Divergent Convergent Transform Structural Environments Extensional Compressional Strike-slip Passive (Salt) 9
EXTENSION COMPRESSION LATERAL UPLIFT, SUBSIDENCE BASEMENT INVOLVED extensional fault blocks contractional fault blocks strike-slip or wrench faulting basement warps BASEMENT DETACHED detached normal faulting fold-andthrust belts tear faults (detached) salt, shale diapirism 10
Shale Oil Trap Structural Hydrocarbon Traps Oil/Gas Contact Gas Closure Fracture Basement Oil/Water Contact Oil Fold Trap Salt Dome Salt Diapir Oil modified from Bjorlykke, 1989) 11
Structural Observations Structural Concepts 12
Structural Observations Fault segments on seismic lines Fault plane orientation Sense of motion Magnitude of offset Range of depths Relative timing when faults moved when structures grew Structural Concepts Tectonic Setting Divergent zones Convergent zones Strike-slip zones Mobile substrate How Structures Evolve Fault-bend folds Fault-propagation folds Salt movement etc. 13
Hydrocarbon Traps - Dome Gas Oil Sandstone Shale Four Dip Closure 14
Triassic Permian Carboniferous 3D Structural Closure, Cooper Basin (Australia) Cooper Basin Triassic Inerval Toolachee Fm Roseneath Shale Epsilon Fm Murteree Fm Patchawarra Tirrawarra Fm Merrimelia Fm Merrimelia Fm: - Starts the Cooper Basin - Waxing and waning of glacial sediments 15
Salt and shale layers can become mobile when subjected to differential loading Imaging beneath salt is very difficult, but the rewards can be great! Many oil and gas fields have been found associated with salt & shale diapirs 16
Targeting the structural high with faults creating a trap 8km 17
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Fault Trap Oil / Gas 20
basement involved basement detached 1 mile Courtesy of ExxonMobil 21
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Fossen, 2010 24
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Seismic section from the JDZ between Nigeria and Sao Tome/Principe. The blue lines indicate thrust faults. PGS 28
Positive Flower Structures 29
Gulf of Guinea, West Africa Intense tectonic activity occurring along a transform margin 30
Depositional Channels Bars Pinch outs Reefs Unconformity Traps Above Unconformity Onlap Valley Fill Channels Diagenetic Traps Permeability Barriers 31
Stratigraphic Observations Stratigraphic Concepts 32
Stratigraphic Observations Seismic Terminations Base of Sequence Top of Sequence Lateral Geometry Map View Channel Pinch Out Reef Relative timing Stratigraphic Concepts Environment of Deposition Fluvial Shallow Marine Deep Marine Carbonate or Terrigenous 33
Stratigraphic Hydrocarbon Traps Unconformity Pinch out Oil/Gas Uncomformity Oil/Gas Channel Pinch Out Oil/Gas (modified from Bjorlykke, 1989) 34
Biddle and Wielchowsky 35
Younger Beds Younger Beds Erosion A top-discordant relationship in which strata terminate along an unconformity surface due to post-depositional erosion Toplap A top-discordant relationship in which strata terminate against a surface mainly as a result of non-deposition (bypass) 36
Older Beds Older Beds Onlap A base-discordant relationship in which younger strata terminate progressively against a surface of greater inclination Downlap A base-discordant relationship in which younger inclined strata terminate progressively against a surface of lower inclination Courtesy of ExxonMobil 37
Onlaps 38
NW SE Tertiary Deep water slope Continued regional subsidence Interbedded shale and sandstone Submarine fan and turbidite deposits 39
Braided Stream Meandering Stream 40
Sandstone Mudstone 41
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3D seismic slice- Fluvial meander at ~2.3 seconds in the West Natuna Basin, Indonesia. ConocoPhillips, Indonesia 43
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Recoverable Reserves: Oil : 10 billion bbls Condensate : 1.3 billion bbls Reservoir: Turbidite sands in a major Eocene submarine canyon Reservoir Thickness 200 to 500 meters Discovered while drilling for deeper Cretaceous limestone. 10% recovery factor 47
Busch, 1992 600 ft sand max 48
Eocene Submarine Canyon System Busch, 1992 49
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4400 4500 4300 4600 Water Oil Structural Contours 4200 Gas 4100 Oil production: 600 mmbbls 54
There is angular discordance between reflections at the yellow line 55
Other Traps Asphalt Trap Water Partly Biodegraded Oil Meteoric Water Biodegraded Oil/Asphalt Hydrodynamic Trap Shale Hydrostatic Head Oil Water (modified from Bjorlykke, 1989) 56
Tozer et al. 2014 57
Tozer et al. 2014 58
Gas Oil 59
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Traps Structural Stratigraphic Combination Other Unconformities are Important Traps Above Valley Fill or Onlap Traps Below - Truncation 61
Assignments Complete All Homework Discuss Current Energy Events Read Today in Energy for Thursday (4/2) at http://www.eia.gov/ Be Prepared to Discuss in Class Monday (4/6) Discussion Leader Alexander Ekvall Test Wednesday April 8 Material Through Monday (4/6) will be on Test 62