Well 5 Well 2 Well 3 Well 4 Well 1

Vail et al., 1977b

AAPG©1977 reprinted with permission of the AAPG

whose permission is required for further use.

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

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

Reservoir rock

Seal

Migration route

Oil/water contact (OWC)

Hydrocarbon accumulation

in the reservoir rock

Top of maturity

Source rock

Fault (impermeable)

6

7

8

Plate Boundaries Divergent

Convergent

Transform

Structural Environments Extensional

Compressional

Strike-slip

Passive (Salt)

9

BASEMENT

INVOLVED

BASEMENT

DETACHED

EXTENSION COMPRESSION LATERAL UPLIFT,

SUBSIDENCE

extensional

fault

blocks

detached

normal

faulting

contractional

fault

blocks

fold-and-

thrust belts

strike-slip

or wrench

faulting

tear faults

(detached)

basement

warps

salt, shale

diapirism

10

Structural Hydrocarbon Traps

Salt Diapir

Oil/Water Contact

Gas Oil/Gas Contact

Oil

Closure Oil Shale Trap

Fracture Basement

(modified from Bjorlykke, 1989)

Fold Trap

Oil

Salt

Dome

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

Oil

Sandstone Shale

Hydrocarbon Traps - Dome

Gas

Four Dip Closure

14

3D Structural Closure, Cooper Basin (Australia)

Merrimelia Fm: - Starts the Cooper Basin - Waxing and waning of glacial sediments

Cooper Basin

Triassic

Triassic Inerval

Perm

ian

Toolachee Fm

Roseneath Shale

Epsilon Fm

Murteree

Fm

Patchawarra

Tirrawarra Fm

Carb

onife

rous

Merrimelia Fm

15

Salt and shale layers can become mobile

when subjected to differential loading

Many oil and gas fields have been found

associated with salt & shale diapirs

Imaging beneath salt is very difficult, but the rewards can be great!

16

Targeting the

structural high with

faults creating a trap

8km

17

18

19

Fault Trap

Oil / Gas

20

Courtesy of ExxonMobil

basement involved basement detached

1 mile

21

22

23

Fossen, 2010 24

25

26

27

28

Seismic section from the JDZ between Nigeria and Sao Tome/Principe. The blue lines indicate thrust faults. PGS

Positive Flower Structures

29

30

Gulf of Guinea, West Africa Intense tectonic activity occurring along a transform margin

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

Oil/Gas

Oil/Gas

Oil/Gas

Stratigraphic Hydrocarbon Traps

Uncomformity

Channel Pinch Out

(modified from Bjorlykke, 1989)

Unconformity Pinch out

34

Biddle and Wielchowsky 35

Younger Beds

Younger Beds

Erosion Toplap

A top-discordant relationship in

which strata terminate along an

unconformity surface due to

post-depositional erosion

A top-discordant relationship in

which strata terminate against a

surface mainly as a result of

non-deposition (bypass)

36

Courtesy of ExxonMobil

Older Beds

Onlap

Older Beds

Downlap

A base-discordant relationship

in which younger strata

terminate progressively against

a surface of greater inclination

A base-discordant relationship

in which younger inclined strata

terminate progressively against

a surface of lower inclination

37

Onlaps

38

Deep water slope

Continued regional

subsidence

Interbedded shale and

sandstone

Submarine fan and

turbidite deposits

Tertiary

NW SE

39

Braided Stream

Meandering Stream

40

Sandstone

Mudstone

41

42

3D seismic slice- Fluvial meander at ~2.3 seconds in the West Natuna Basin, Indonesia. ConocoPhillips, Indonesia

43

44

45

46

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

50

51

52

53

Gas

Oil

Water

Structural Contours

Oil production: 600 mmbbls

4100

4300

4200

4400

4500

4600

54

There is angular discordance between reflections at the yellow line

55

Asphalt Trap

Water

Meteoric Water

Biodegraded Oil/Asphalt

Partly Biodegraded Oil

Hydrodynamic Trap

Shale

Oil Water

Hydrostatic Head

(modified from Bjorlykke, 1989)

Other Traps

56

57

Tozer et al. 2014

58

Tozer et al. 2014

Gas

Oil

59

60

Traps Structural

Stratigraphic

Combination

Other

Unconformities are Important Traps Above – Valley Fill or Onlap

Traps Below - Truncation

61

62

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