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ADVANCED STRUCTURAL GEOLOGY FOR PETROLEUM EXPLORATION SHORT COURSE 2008

Seismic Exercises - Answers Professor Ken McClay Fault Dynamics Research Group Royal Holloway University of London

Seismic Exercises - Extension

0

Sea Bed

Sea Bed

Growth Sequence 4

Growth Sequence 4

Growth Sequence 3

1 TWT (sec) Growth Sequence 3

2

??? ?

?

Unconformity

?

3

Growth Sequence 1 ?

?

? Footwall Fault

Growth Sequence 2

ʻPull-Upʼ ? Distorted Reflections

4

Fault Plane Reflector

Overpressured Shale

Growth Sequence 4

?

?

Growth Sequence 1

Growth Sequence 3 Growth Sequence 2 ?

Growth Sequence 1 Overpressured Shale

?

Small Triangular Footwall Roller of Shale below Fault 2 km

?

Exercise ES 1

© K.R. McClay 2008

1

Seismic Exercises - Extension

TWT (sec) 0.0 Crestal Collapse Graben

Sea Floor

1.0

2.0

??

Seismic Artefact

3.0

?? ?? Poor Imaging

4.0 Seismic Pull-Up

?? ??

Seismic Artefact

5.0 2 km 6.0 Sub-Salt

Salt

Syn-Extension I

Syn-Extension II

Syn-Extension III

Exercise ES2

© K.R. McClay 2008

2

Seismic Exercises - Extension

TWT (sec) 1.0

1.5

Bright Spots

MTC 2.0

2.5

Bright Spots

3.0 2 km

Syn-Extension I

MTC?

Syn-Extension II

Syn-Extension III

Syn-Extension IV

Overpressured Zone

Exercise ES3

© K.R. McClay 2008 3

Seismic Exercises - Extension TWT (sec) 0Sea Bed

Eocene-Miocene

D7

1PR3 PR3 PR2

D1 PR2 2-

Velocity Pull-Up

PR3

PR1

Salt Syn-Rift?

PR1

PR2 ?

3? ?

Syn-Rift Basement?

Basement? ?

4-

?

2 km

EoceneMiocene

© K.R. McClay 2008

D1-D7 Cenomanian Clastics Syn-Raft Tectonics

PR3 Post-Rift Carbonates

PR2 Post-Rift Carbonates

PR1 Post-Rift Albian Carbonates

Aptian Salt

Syn-Rift Neocomian

Exercise ES-4

Salt Weld

4

Seismic Exercises - Extension

TWT (sec) 0.0

1.0

2.0

Top of Basement Uncertain

Ramp-Flat Detachment in Basement

2 km

Exercise ES5

© K.R. McClay 2008

Basement

Syn-Rift I

Post-Rift Post-Inversion I Syn-Inversion? 5

Post-Inversion II

Seismic Exercises - Extension

TWT (sec) 0 Post-Rift 4

1

2

Lacustrine?

Eroded Fault Plane?

Granite? Basement

Inversion Basement Granite? Basement

Basement Marginal Fan System or Slight Inversion?

Lacustrine Sequence

2 km

Post-Rift 4 Fluvio- Lacustrine

Post-Rift 3 Fluvio-Lacustrine

Post-Rift 2 Lacustrine

Post-Rift 1 Fluvial?

Syn-rift 1 Lacustrine

Basement

Exercise ES 6

© K.R. McClay 2008

6

Seismic Exercises - Extension

NE

SW TWT secs

TWT secs

0.0

0.0

Sea Floor

1.0

1.0

2.0

2.0

3.0

3.0

4.0

Crystalline Basement

Crystalline Basement

4.0

5 km

Post-Rift 3

Post-Rift 2

Post-Rift 1

© K.R. McClay 2008

Syn-Rift 2

Syn-Rift 1

Basement

Exercise ES 7 7

Seismic Exercises - Extension

0 TWT (sec) 1

Land Surface

Land Surface

Poor Near Surface Reflections

Post-Rift 3

Post-Rift 3 Post-Rift 1

Post-Rift 2

Post Rift 1

PR1

Post Rift 1

1b 1a

1b 1b

1a

2

1b

1a

Crystalline Basement

1a

Crystalline Basement

Post-Rift 3

Crystalline Basement Post-Rift 2

Basement

4 km Syn-Rift? 1b

Post Rift 1

Syn-rift 1a

Basement

Exercise ES 8

© K.R. McClay 2008

8

Seismic Exercises - Extension

TWT (sec) 0.0

? 1.0

? 2.0

Wedging Fan Systems?

3.0

4.0

5.0

Basement

Syn-Rift I

Syn-Rift II

Syn-Rift III

Post-Rift I

Post-Rift II

Exercise ES 9

© K.R. McClay 2008

9

Seismic Exercises - Extension

TWT (sec) 0.0

Sub-Basin 1 Rift Border Fault

Sub-Basin 3

Sub-Basin 2

Inversion Against Rift Border?

‘Conjugate fault arrays’

1.0

2.0

3.0

Strongly faulted basement

2 km 4.0

Basement

Syn-Rift I

Syn-Rift II

Syn-Rift III

Post-Rift I

Post-Rift II

Exercise ES10

© K.R. McClay 2008

10

Seismic Exercises - Extension

TWT sec 0

Sea Bed

1 Dyke in Fault

2

?

Strong Reflector Fan?

? ? 3

?

?

Basement

Syn-Inversion 2b

?

Basement

?

Syn-Inversion 2a

Syn-Inversion 1

Syn-Rift 2

Syn-Rift 1

Basement

Basic Intrusion

Exercise ES 11

© K.R. McClay 2008

11

Seismic Exercises - Extension Sea Floor

u/c

u/c u/c

u/c

u/c Seismic Artefact

2 km

Basement

Syn-Rift I

Post-Rift I

Post-Rift II

Post-Rift III

Exercise ES12

© K.R. McClay 2008 12

Seismic Exercises - Extension

TWT (sec) 0.0

NE

SW

u/c

1.0

u/c

2.0

3.0 5 km

© K.R. McClay 2008

Basement

Pre-Rift I

Pre-Rift II 13

Post-Rift

Exercise ES13

Seismic Exercises - Extension

TWT (sec)

0.0

1.0

2.0

3.0

4.0

2 km 5.0 Basement

Syn-Rift I

Syn-Rift II

Syn-Rift III

Syn/Post-Rift

Post-Rift/ Post-Inversion (?) Syn-Inversion

Exercise ES14

© K.R. McClay 2008 14

Seismic Exercises - Extension TWT (sec)

1.0

2.0

3.0

4.0

0

Basement © K.R. McClay 2008

Syn-Rift (1)

Syn-Rift (2)

15

Post-Rift

5km

Syn-Inversion

Exercise ES 15

TWT (sec) 0.0

Seismic Exercises - Extension Sea Floor

1.0

2.0

3.0

5 km

Basement

Syn-rift (1)

Syn-Rift (2)

16

Post-Rift (1)

Post-Rift (2)

Exercise ES 16 © K.R. McClay 2008

Seismic Exercises - Extension

TWT (sec) Sea Floor

1.0

2.0

?

?

? ?

? ?

3.0

? ?

4.0

5 km Basement

Syn-Extension 1

Syn-Extension 2

© K.R. McClay 2008 17

Syn-Inversion

Post-Inversion

Exercise ES 17

Seismic Exercises - Extension

TWT (sec)

5.0

Sea Floor

6.0

Basement Post-Extension ? 7.0

Basement

8.0

Basement

Basement Top of basement difficult to pick

2 km

Exercise ES 18 Basement

Syn-Extension ?

Post-Extension 1

18

Post-Extension 2 Deepwater Trubidite Systems

© K.R. McClay 2008

Seismic Exercises - Inversion

Sea Bed

Sea Bed

TWT (sec)

? ?

Multiples

- 1.0

?

- 2.0 ? ? ?

‘Basement’ Pre-Rift

- 3.0 Post-Inversion ‘Basement’ Pre-Rift Syn-Inversion ?

Syn-Rift

Post-Rift 2

Pre/Syn-Rift ?

Post-Rift 1

Basement Pre-Rift

© K.R. McClay 2008

2 km 19

Exercise IS 1

Seismic Exercises - Inversion

TWT (sec)

1.0 MTC?

Slumps

2.0

2.5 km 3.0

Basement © K.R. McClay 2008

Syn-Rift 1

Syn-Rift 2

Syn-Rift 3

Post-Rift Syn-Inversion 1 ? 20

Syn-Inversion 2

Syn-Inversion 3

Post Inversion

Exercise IS 2

TWT (sec)

Seismic Exercises - Inversion

1.0

2.0

2.5 km Basement © K.R. McClay 2008

Syn-Rift 1

Syn-Inv 2

Syn-Inv 1 21

Syn-Inv 3

Syn-Inv 4

Post Inv

Exercise IS 3

Seismic Exercises - Inversion

TWT (sec) 0.0 Poor Data Quality

V

IV

0.5

IV II Ic Ib

IIIc II

1.0

Ia

Ic Ib 1.5

IIIa

?

IIIb

Ic Ib

?

Ia ?

IIIc

?

Ia

? Footwall Shortcut

2.0

Inverted Basin Margin Fault Basement

Basement

2.5

Basement

1c Pre-Extension 1b Pre-Extension

II Post-Extension

1a Pre-Extension

IIIc Syn-Inversion 1 IIIb Syn-Inversion 1 IIIa Syn-Inversion 1

IV Post-Inversion 1 V Post-Inversion 2

Exercise IS 4

© K.R. McClay 2008

22

Seismic Exercises - Inversion

0 Post-Inversion

IId

IId

TWT (sec) IIc

1

Post-Rift

IIc

Ic

Ib

Ic Ia

IIb

IIa

Ib

Ia

2 Basement

Post-Inversion

Syn-Inversion IIc

Syn-Inversion IIa Late Cretaceous

Pre-Rift Ic

Pre-Rift Ia

Syn-Inversion IId Miocene

Syn-Inversion IIb

Post-Rift Lower Cretaceous

Pre-Rift Ib

Basement Pre-Triassic

© K.R. McClay 2008

Exercise IS 5

23

Seismic Exercises - Inversion

TWT sec 0

Sea Bed

1

Dyke in Fault Strong Reflector

?

2

?

? ?

?

Basement ?

?

?

3 ? Basement

Syn-Inversion 2b

Syn-Inversion 2a

Syn-Inversion 1

Syn-Rift 2

© K.R. McClay 2008

Syn-Rift 1

Basement

Basic Intrusion

Exercise IS 6

24

Seismic Exercises - Inversion

TWT (sec) 0.0

1.0

2.0

3.0 Fluvial Channels (?) Footwall Shortcut Intra-Basement Reflectors

4.0

5 km 5.0 Basement

© K.R. McClay 2008

Syn-Rift

Syn-Inversion I 25

Syn-Inversion II

Syn-Inversion III

Post-Inversion

Exercise IS7

Seismic Exercises - Inversion

TWT (sec) 1.0

Sea Floor

1.5

2.0

2.5

3.0 Footwall Shortcut

3.5

4.0

Basement Syn-Rift I

Syn-Rift Syn-Inversion Syn-Inversion Syn-Inversion PostInversion II I II III

© K.R. McClay 2008

Exercise IS 8 26

Seismic Exercises - Inversion

TWT secs

S

N

? Steeply Dipping Beds

1.0

?

?

2.0

3.0

5 km Basement

Syn-Rift 1

Syn-Rift 2

Syn-Rift 3

Syn-Rift 3

© K.R. McClay 2008

Syn-Inv 1

Syn-Inv 2

Syn-Inv 3

Exercise IS 9 27

TWT Secs

Seismic Exercises - Inversion

S

N

1.0

?

Zig-Zag Faults

2.0

?

?

3.0

2 km Exercise IS 10

© K.R. McClay 2008 Basement

Syn-Rift I

Syn-Rift to Post Rift 28

Syn-Inversion I

Syn-Inversion II

Post-Inversion

Seismic Exercises - Inversion

TWT Secs

S

N

1.0 ?

2.0

? ?

3.0 Volcanics Volcanics

2 km © K.R. McClay 2008

Exercise IS 11 Basement

Syn-Rift I

Syn-Rift to Post Rift

Syn-Inversion I 29

Syn-Inversion II

Post-Inversion

Seismic Exercises - Inversion

SSE

NNW Sea Floor Post-Inversion

Sea Floor

0.0 TWT (sec)

Channels?

U/C IIc

IIc

U/C

IIb

IIb

IIc

U/C

IIb

IIa

1.0

IIa

U/C

Pr

U/C

Post-Rift IIa

Ic Ic

Ic

Ib

2.0

Ib

Ia

U/C Ic Footwall Deformation

Ia

Ib

3.0 Basement ?

Highly Disturbed Reflectors Approximate Position of Main Inverted Fault

Post Inversion © K.R. McClay 2008

IIc

IIb

IIa

Post Rift

Syn-Inversion

Syn-Rift Ia, Ib & Ic

5 km Basement

Exercise IS 12

30

Seismic Exercises - Inversion

TWT (sec) 0.0 Sea Floor

Syn-Inversion V

Syn-Inversion IV

Syn-Inversion III 1.0 Syn-Inversion II

Syn-Inversion I

Syn-Rift II

2.0

Syn-Rift I

Basement 2 km

Exercise IS 13

© K.R. McClay 2008 31

TWT (sec)

Seismic Exercises - Inversion

Sea Bed

Multiples 1.0

?

Channels

? ? 2.0

?

3.0

Steep Extension Fault

Post-Inversion Syn-Inversion

4.0

Post-Rift Syn-Rift

‘Basement’ - Pre-Rift ‘Basement’ Pre-Rift ‘Basement’ Pre-Rift 2 km © K.R. McClay 2008

32

Exercise IS 14

Seismic Exercises - Inversion

TWT secs

E

W

0.0Steeply Dipping Beds ?

? 1.0-

? ? ?

? ?

?

2.0?

?

3.02 km

© K.R. McClay 2008

Basement Lower Palaeozoic

Syn-Rift ? Triassic ?

Post-Rift 1 Lower Cretaceous ? 33

Post-Rift 2 Upper Cretaceous ?

Syn-Inversion ? Neogene

Exercise IS 15

Seismic Exercises - Strike-Slip

0 Eroded Fault Scarp?

TWT (sec)

Drag into Flower Structure Probable Syn-Kinematic Strata

1

?

2

Detached at Depth ? ?

1 km

Exercise SS 3

© K.R. McClay 2008

34

Seismic Exercises - Strike-Slip

NE

W

Springer Fm (Mississippian) Sycamore Fm (Mississippian) 2 km Basement

Oil Creek Fm (Ordovician)

H=V

T

A

Exercise SS 4

© K.R. McClay 2008

35

Seismic Exercises - Thrust Systems

TWT (sec) 0.0 Prograding units

2.0

4.0

? Imbricate thrusts

6.0

? 8.0

2 km

Pre-Growth I

Pre-Growth II

Pre-Growth III

Growth I

Growth II

Growth III

Growth IV

Post-Growth

Exercise TS1

© K.R. McClay 2008 36

Seismic Exercises - Thrust Systems

(km) 0.0

Progradational wedges

5.0

10.0 5 km

Pre-Growth I

Pre-Growth II Pre-Growth III

Growth I

Growth II

© K.R. McClay 2008

Growth III

Growth IV

Growth V

Growth VI

Exercise TS2 37

Seismic Exercises - Thrust Systems

E

W Seabed

TWT (sec)

4.0

5.0

6.0 2 km

Exercise TS3

© K.R. McClay 2008

Pre-kinematic I

Pre-kinematic II

Pre-kinematic III

38 Pre-kinematic IV

Pre-kinematic V

Syn-kinematic

Post-kinematic

Seismic Exercises - Thrust Systems

TWT secs 0

Agip - Budrio 1

TWT secs 0

Agip - Selva 2

Quaternary

1

1 Middle Late Pliocene

2

2

Early Pliocene MiocenePaleogene

Top of Miocene Sequence

3

3

4

4 Top of Mesozoic Carbonate Sequence Detachment Surface

5

5 5 km

6

6 Quartenary Middle Late Pliocene

Miocene-Paleogene Syn-Kinematic Growth Strata

Middle Pliocene

Mesozoic Carbonates

Early Pliocene © K.R. McClay 2008

Exercise TS 4 39

Seismic Exercises - Thrust Systems

TWT (sec) W 0

E Topographic Surface

1 2 3 Detachment in Ductile Shales

4 Top Marker

Green Marker

Brown Marker

Carbonate

Ductile Shales

Footwall Units

1 km

Exercise TS 5

© K.R. McClay 2008

40

Seismic Exercises - Thrust Systems

(km) 0.0 Top of seismic data

Para-Autochthonous Sequence

Allochthonous Sequence 1.0

2.0

3.0

4.0

Footwall Sequence

1 km 5.0

© K.R. McClay 2008

Exercise TS6

41

Seismic Exercises - Thrust Systems

TWT (sec) 4.0

5.0

?

6.0

7.0

? 2 km

?

?

?

Basement

Pre-Salt

Salt

Pre-Growth I

Pre-Growth V

Growth I

Growth II

Growth III

Pre-Growth II Pre-Growth III Pre-Growth IV Growth IV

Post-Growth I Post-Growth II

Exercise TS7

© K.R. McClay 2008 42

Seismic Exercises - Thrust Systems

TWT (sec) 4.0

5.0

6.0

7.0

? ? 8.0 2 km

Basement Pre-Rift

Salt

Pre-Growth I

Pre-Growth II

Pre-Growth III

Growth I

Growth II

Growth III Post-Growth

Exercise TS 8

© K.R. McClay 2008 43

Seismic Exercises - Thrust Systems

TWT (sec) 4.0 BSR

5.0

6.0

7.0

2 km

© K.R. McClay 2008

Pre-Kinematic

Syn-Kinematic 44

Exercise TS9

Seismic Exercises - Thrust Systems Sea Floor

TWT (sec) 3.0

4.0

5.0

6.0

2 km

Exercise TS 10 Pre-Kinematic I

Pre-Kinematic II

Pre-Kinematic III

Syn-Kinematic I Syn-Kinematic II

Syn-Kinematic III

45

Pre-Kinematic IV

© K.R. McClay 2008

Seismic Exercises - Thrust Systems

Sea Floor

TWT (sec) 4.0

5.0

6.0

2 km

Exercise TS 11

© K.R. McClay 2008

Detachment Unit Pre-Growth I

Growth I

46

Growth II

Growth III

Growth IV

Post-Growth

Seismic Exercises - Thrust Systems

TWT (sec) Sea Floor

3.0

? ?

4.0

5.0

2 km

6.0

Exercise TS12

© K.R. McClay 2008 Pre-Growth

Growth I

Growth II 47

Growth III

Growth IV

Seismic Exercises - Thrust Systems

TWT (sec) 4.0

6.0

5 km

Exercise TS 13

© K.R. McClay 2008 Pre-kInematic I

Pre-kInematic II

Pre-kInematic III 48

Syn-Kinematic I

Syn-Kinematic II

Syn-Kinematic III

Seismic Exercises - Thrust Systems

TWT (sec) 3.0

Ponded hangingwall basins Slumps Slumps

4.0

BSR

Sea Floor

Poor migration

5.0

6.0

Poor seismic imaging

7.0

2 km

Pre-Growth

Growth I

Growth II

Growth III

Growth IV

Exercise TS 14

© K.R. McClay 2008 49

Seismic Exercises - Thrust Systems

TWT (sec) 4.0

Sea Floor BSR

5.0

6.0

5 km

Exercise TS 15

© K.R. McClay 2008

Pre-Kinematic I

Pre-Kinematic II

Pre-Kinematic III 50

Pre-Kinematic IV

Syn-Kinematic

Seismic Exercises - Thrust Systems

W

E

Outer Arc Extensional Faults

TWT (sec)

BSR

3.0

4.0

5.0 1 km

Exercise TS 16

© K.R. McClay 2008 Pre-Kinematic

Pre-Kinematic II

Pre-Kinematic 51 III

Syn-Kinematic I

Syn-Kinematic II

Seismic Exercises - Thrust Systems

TWT (sec) 2.0

3.0

Seabed

4.0

5.0

6.0

2 km

© K.R. McClay 2008

Exercise TS 17

52

Pre-kInematic I

Pre-kInematic II

Pre-kInematic III

Syn-Kinematic

Seismic Exercises - Thrust Systems

TWT (sec) 3.0

4.0

5.0

6.0

2 km © K.R. McClay 2008

Exercise TS18 Pre-kInematic I

Pre-kInematic II

Pre-kInematic III 53

Syn-Kinematic