Seismic Attributes - Tectonics

6a-1

Seismic Attribute Mapping of Structure Seismic Attribute Mapping of Structure

and Stratigraphy and Stratigraphy

Attribute Expression of Tectonic DeformationAttribute Expression of Tectonic Deformation

Kurt J. Marfurt (University of Oklahoma)Kurt J. Marfurt (University of Oklahoma)

6a-2

Course OutlineCourse Outline

IntroductionIntroduction

Complex Trace, Horizon, and Formation AttributesComplex Trace, Horizon, and Formation Attributes

Multiattribute DisplayMultiattribute Display

Spectral DecompositionSpectral Decomposition

Geometric AttributesGeometric Attributes

Attribute Expression of GeologyAttribute Expression of Geology

Impact of Acquisition and Processing on AttributesImpact of Acquisition and Processing on Attributes

Attributes Applied to OffsetAttributes Applied to Offset-- and Azimuthand Azimuth--Limited VolumesLimited Volumes

StructureStructure--Oriented Filtering and Image EnhancementOriented Filtering and Image Enhancement

Inversion for Acoustic and Elastic ImpedanceInversion for Acoustic and Elastic Impedance

Multiattribute Analysis ToolsMultiattribute Analysis Tools

Reservoir Characterization WorkflowsReservoir Characterization Workflows

3D Texture Analysis3D Texture Analysis

6a-3

Attribute expression of tectonic deformationAttribute expression of tectonic deformation

After this section you should be able to:

• Use coherence to accelerate the interpretation of faults on 3-D volumes,

• Use volumetric attributes to provide a preliminary interpretation across multiple surveys having different amplitude and phase,

• Identify the appearance and structural style of salt and shale diapirs on geometric attributes,

• Use curvature to define axial planes, and

• Use coherence and curvature as an aid to predicting fractures.

6a-4

N

E

S

W

EastWest

Gentle

South

Dip

Moderate

West dip

Gentle

North

dip

Northeast

dip

Moderate

Southeast

dip

Growth faults, Gulf of MexicoGrowth faults, Gulf of Mexico

6a-5

N

E

S

W

Growth faults, Gulf of MexicoGrowth faults, Gulf of Mexico

00

66

44

22

Tim

e (

s)

Tim

e (

s)

6a-6

Identification of faults (Gulf of Mexico, USA)Identification of faults (Gulf of Mexico, USA)

Salt

Salt

6a-7

Identification of faults (Alberta, Canada)Identification of faults (Alberta, Canada)

6a-8

4.0

2.0

3.0

1.0

1.0

2.0

3.0

0.0

Tim

e (

s)

5 k

m

4.0

2.0

3.0

1.0

1.0

2.0

3.0

0.0

Tim

e (

s)

5 k

mSeismicSeismic CoherenceCoherence

Identification of faults and stratigraphyIdentification of faults and stratigraphy(Gulf of Mexico, USA)(Gulf of Mexico, USA)

FaultsFaults

‘‘BandingBanding’’

‘‘StratigraphyStratigraphy’’

6a-9

Attribute imaging of faults and flexuresAttribute imaging of faults and flexures

6a-10

Fault not seen Fault not seen

on curvature.on curvature.

Seen on Seen on

coherence.coherence.

Fault seen on Fault seen on

curvature. curvature.

Seen on Seen on


Idealized Idealized

growth growth

faultfault

Idealized Idealized

strikestrike--slip slip

faultfault

6a-11


coherence. coherence.

Not seen on Not seen on

curvature.curvature.


curvature.curvature.



Fault with Fault with

minimal minimal

offsetoffset

Fault with Fault with

finite finite

offsetoffset

6a-12

Fault seen on coherence Fault seen on coherence

at depth. Infill/collapse at depth. Infill/collapse

seen on curvature seen on curvature

shallow.shallow.

‘‘FaultFault’’ seen seen

on curvature.on curvature.



Folds and Folds and

flexuresflexuresInfilledInfilled

grabensgrabens

6a-13

BasinwideBasinwide Regional Interpretation across Regional Interpretation across

Heterogeneous Seismic SurveysHeterogeneous Seismic Surveys

6a-14

10 km

1.0

1.2

1.4

1.6

0.8

Time (s)

N

Time/structure map of heterogeneous surveysTime/structure map of heterogeneous surveys

Central Basin Central Basin

Platform, Platform,

Texas, USATexas, USA

Top DevonianTop Devonian

6a-15

1.0

0.8

Coh

10 km

N

Coherence time slice on heterogeneous surveysCoherence time slice on heterogeneous surveys

Central Basin Central Basin

Platform, Platform,

Texas, USATexas, USA

t=1.0 st=1.0 s

(Data courtesy (Data courtesy

of BP, OXY, of BP, OXY,

Burlington)Burlington)

6a-16 (Biles et al, 2003).

A large regional surveyA large regional survey

Eugene Island

Ship Shoal

VermillionSouth

VermillionSouth MarshIsland

TexasLouisiana

EastCameron

WestCameron

Gulf of Mexico

6a-17 (Biles et al, 2003).

Use of coherence to interpreter a large regional surveyUse of coherence to interpreter a large regional survey

‘Coherence’ at 3.0 s

TexasLouisiana

Gulf of Mexico

6a-18

Interpretation WorkflowsInterpretation Workflows

6a-19

N

EW

S

low coh

mid coh

high coh

2 kmN

EW

S

N

EW

S

(Data courtesy of OXY)

Workflow#1: Using attribute to delineate limits Workflow#1: Using attribute to delineate limits

of fault of fault zoneszones

6a-20

A A′′′′

B

B′′′′

C

N

5 km

Workflow#2: Using attribute time slices to help Workflow#2: Using attribute time slices to help

correlate horizons across faultscorrelate horizons across faults

Coherence time Coherence time

slice. T=2.7 sslice. T=2.7 s

(Green Canyon, (Green Canyon,

GOM, USA)GOM, USA)

SaltSaltPick an arbitrary Pick an arbitrary

line that runs line that runs

around faultsaround faults

6a-21

C

B B′′′′2.0

2.5

3.0

Tim

e (

s)

A A′′′′4 km

C2.0

2.5

3.0

Tim

e (

s)

C

Seismic Seismic ‘‘traversetraverse’’

chosen to avoid chosen to avoid

major faultsmajor faults

(Data courtesy of BP)(Data courtesy of BP)

6a-22

N

3 km

Workflow #3: Workflow #3:

Using Using

attributes to attributes to

help fault help fault

naming and naming and

correlationcorrelation

coherencecoherence seismicseismic

t=2.6 st=2.6 s t=2.6 st=2.6 s

Northwest Louisiana, Northwest Louisiana,

USAUSA

(Data courtesy of Seitel)(Data courtesy of Seitel)

6a-23

N

3 km

N

3 km

1) Pick on coherence 1) Pick on coherence

using seismic time using seismic time

slice as a guide. Try slice as a guide. Try

to avoid to avoid

stratigraphic stratigraphic

discontinuities and discontinuities and

unconformitiesunconformities


t=2.6 st=2.6 s t=2.6 st=2.6 s


6a-24


2) Choose a seismic 2) Choose a seismic

line perpendicular to line perpendicular to

the fault traces. Pick the fault traces. Pick

and assign faults as and assign faults as

you normally would.you normally would.

A A′′′′

Top Cotton

Valley

Bott

om

Cott

on V

alley

A A′′′′

N

3 km

2.5

2.0

3.0

Tim

e (

s)

t=2.6 st=2.6 s


6a-25


3) Choose a 23) Choose a 2nd nd EW EW

seismic line further seismic line further

down the fault trace down the fault trace

to begin forming a to begin forming a

coarse fault grid.coarse fault grid.

B B′′′′

2.5

2.0

3.0

Tim

e (

s)

A A′′′′

B B′′′′

t=2.6 st=2.6 s


6a-26


4) Pick a NS line and 4) Pick a NS line and

continue the continue the

process. If subtle process. If subtle

discontinuities seen discontinuities seen

to be faults on to be faults on

seismic, track them seismic, track them

on coherence.on coherence.2.5

2.0

3.0

Tim

e (

s)

N

3 km

C

C′′′′

C C′′′′

t=2.6 st=2.6 s


6a-27


5) Pick additional NS 5) Pick additional NS

lines and continue lines and continue

the process, forming the process, forming

a coarse grid.a coarse grid.

D

D′′′′

D D′′′′

2.5

2.0

3.0

Tim

e (

s)

t=2.6 st=2.6 s


6a-28

6) Pick a new time 6) Pick a new time

slice through the slice through the

coherence volumecoherence volume

coherencecoherence coherencecoherence

t=2.5 st=2.5 s t=2.7 st=2.7 s


6a-29

coherencecoherence coherencecoherence

t=2.5 st=2.5 s t=2.7 st=2.7 s

7) Use the cross7) Use the cross--

posted fault picks posted fault picks

from the vertical from the vertical

seismic to guide seismic to guide

your interpretation your interpretation

on the seismic on the seismic

coherence slicescoherence slices


6a-30

Structural DeformationStructural Deformation

6a-31

Offshore Trinidad Time Slice (t=1.2 s)Offshore Trinidad Time Slice (t=1.2 s)

N

2 km 2 km

Galeota Ridge

Seismic Coherence

Complex

faulting

difficult to

detect on

seismic

Coherence

shows

lateral

continuity

of faults

(Gersztenkorn et al., 1999)

6a-32

Coherence Time Slice (1.1 s)

Dip / AzimuthTime Slice (1.1 s)

(Gersztenkorn et al., 1999)

NW

ESN

E

D

D′

E′

D

D′

E E′

2 km

6a-33 (Gersztenkorn et al., 1999)

Seismic DataSeismic Data

E′E

Tim

e (

s)

1.5

1.1

0.7

D D′

Tim

e (

s)

1.3

1.1

0.9

2 km

6a-34

P

P′′′′

Q

Q′′′′

R′′′′

R

P

P′′′′

Q

R′′′′

R

P

P’

Q

R’

R

Q′′′′ Q′′′′

neg

pos

Curv

0

1.0

0.8

Coh

Teapot Dome (WY, USA)Teapot Dome (WY, USA)

CoherenceCoherence Most Positive Most Positive

CurvatureCurvatureMost Negative Most Negative

CurvatureCurvature

6a-35

Teapot Dome (WY, USA)Teapot Dome (WY, USA)T

ime

(s

)

1.5

0.5

1.0

P′′′′ R′′′′RP Q Q′′′′

(Data courtesy of RMTOC)(Data courtesy of RMTOC)

6a-36

Reverse Faulting (Alberta, Canada) Reverse Faulting (Alberta, Canada)

A

A’

A A’

Neg Pos0

Low High

(Chopra and Marfurt, 2007b)

6a-37

Line 1

Line 3

Line 4

Line 5

Line 6

Line 2


Coherence Strat SlicesCoherence Strat Slices

6a-38

Line 1

Line 3

Line 4

Line 5

Line 6

Line 2


MostMost--Positive Curvature Strat SlicesPositive Curvature Strat Slices

6a-39

Line 1

Line 3

Line 4

Line 5

Line 6

Line 2


MostMost--Negative Curvature Strat SlicesNegative Curvature Strat Slices

6a-40

Neg Pos0


Line 1

1000 ms

1600 ms Line 3Line 2 Line 4

Line 5 Line 6

Faults that appear as

discontinuities (seen

on both coherence and curvature horizon

slices)

Flexures seen on most

positive curvature

horizon slice that do

not appear coherence

slice

1000 ms

1600 ms

6a-41

Salt and Shale DiapirismSalt and Shale Diapirism

6a-42

Vertical seismic section through the

La Rue salt dome, East Texas, USA

(Maione, 2001)

.

4350

11300

20900

Dep

th (ft)

1.0

2.0

3.0

La RueSalt

Dome

PECAN GAP CHALK

BUDA LIME

JAMES LIME

AUSTIN CHALK

JAMES LIME

COTTON

SALT WELD

LIMEVALLEY

LOUANN SALT

3 mi

Tim

e (

s)

6a-43

Isochron contour map of the interval between theIsochron contour map of the interval between the

James and Buda LimestonesJames and Buda Limestones

(Maione, 2001).

SALT

WITHDRAWAL

BASIN

>1300 ms

~ 600 ms

8 km1.4 s

1.9 s

6a-44 (Maione, 2001).

Ring faults difficult to see on seismic data, easier to see on Ring faults difficult to see on seismic data, easier to see on

coherencecoherence

Time slice through La Rue Salt Dome, East Texas, USATime slice through La Rue Salt Dome, East Texas, USA

6a-45

8 km

La RueSalt

Dome

Salt Dome

Salt Dome

Time slice through coherence volumeTime slice through coherence volume

Time slice at 1.232 s

(Maione, 2001).

6a-46


8 km


Salt Dome

Salt Dome

La RueSalt

Dome

(Maione, 2001).

6a-47

8 km


La RueSalt

Dome

Salt Dome

Salt Dome


(Maione, 2001).

6a-48

Coherence volume, looking South, showing concentric ring fault

patterns and stratigraphic thickening

(Maione, 2001).

La RueSalt

Dome

8 km

N

6a-49

Vertical section between two salt withdrawal basins

Seismic Coherence

3 km

(Maione, 2001).

1.5

1.0

2.0

6a-50

Mapping Folds and FlexuresMapping Folds and Flexures

6a-51

Seismic amplitudeSeismic amplitude CoherenceCoherence

highhigh

00

highhigh

lowlow

5 km

Most positive curvatureMost positive curvature

highhigh

00

Central Basin Platform, Texas, USACentral Basin Platform, Texas, USA

Horizon slices along Horizon slices along

DevonianDevonian

(Blumentritt et al., 2006)

6a-52

Pick lineaments seen on curvaturePick lineaments seen on curvature

Methodology

highhigh

00


2 km

6a-53

Interpretation of Interpretation of

LineamentsLineaments

Red and Blue

lines: Readily observable faults

Green lines: Subtle geologic

features


Deformation

model

6a-54

Application

What is the geologic explanation of these What is the geologic explanation of these

lineaments?lineaments?

2 km


6a-55

Buckling in Competent Rocks?Buckling in Competent Rocks?Application


6a-56

Structural DeformationStructural Deformation

In Summary:In Summary:•• In general, time slices show better fault images (with less inteIn general, time slices show better fault images (with less interpreter bias) than rpreter bias) than

horizon slices.horizon slices.

•• Geometric attributes are relatively insensitive to the seismic Geometric attributes are relatively insensitive to the seismic source wavelet, source wavelet,

such that they are useful in visualizing geologic features that such that they are useful in visualizing geologic features that span surveys span surveys

subjected to different acquisition and processing.subjected to different acquisition and processing.

•• Geometric attributes allow us to quickly define and name a coarGeometric attributes allow us to quickly define and name a coarse fault se fault

network.network.

•• Volumetric curvature allows us to map subtle folds and flexuresVolumetric curvature allows us to map subtle folds and flexures associated associated

with tectonic deformation.with tectonic deformation.

•• Volumetric curvature also illuminates faults that are inaccuratVolumetric curvature also illuminates faults that are inaccurately imaged or ely imaged or

have small vertical throw.have small vertical throw.

•• Geometric attributes allow us to visualize plastic deformation Geometric attributes allow us to visualize plastic deformation in ductile shales in ductile shales

and brittle deformation in more competent carbonates and sandstoand brittle deformation in more competent carbonates and sandstones.nes.

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Seismic Attributes - Tectonics