imaging sand distribution from acoustic impedance suphan buri basin, central thailand

Imaging Sand Distribution From Acoustic Impedance Imaging Sand Distribution From Acoustic Impedance

Suphan Buri Basin, Suphan Buri Basin,

Central Thailand.Central Thailand.

Imaging Sand Distribution From Acoustic Impedance Imaging Sand Distribution From Acoustic Impedance

Suphan Buri Basin, Suphan Buri Basin,

Central Thailand.Central Thailand.

Dept. Petroleum Geoscience, Universiti Brunei Darussalam.

PTT Exploration and Production PCL., Bangkok, Thailand.

Ronghe, S., and Surarat, K.1 2

1

2

CONTENTS

• Study objectives• Location and geology• Wireline analysis• Well to seismic correlation• Seismic attribute analysis• Inverse modeling• Results and interpretation• Conclusions• Acknowledgements

STUDY OBJECTIVES

• To determine the potential of wireline and seismic as a discriminator of formation lithology / fluid.

• To apply the seismic inversion to image depositional succession

STUDY LOCATION STUDY LOCATION STUDY LOCATION STUDY LOCATION

PhitsanulokBasin

Sing BuriBasin

KamphaengSaen Basin

Ayuthaya Basin

Sala Daeng Basin

THAILAND

BANGKOK

Three Pagodas

Fault Zone

Mae Ping Fault Zone

30 km

N

Adapted from O’Leary and Hill (1989)

STUDY AREA

Suphan Buri Basin

Oli

goce

neM

ioce

neP

lioc

ene

- R

ecen

t

Low

erM

idU

pper

Age Unit

U

A

B

C

D

E

C1

C2

Pre Tertiary

C3

C4

D7

D1

D6

D5

D4

D3

D21000 -

U

1500 -

2000 -

500 -

m

Alluvial - Fluvial

Depositional system

Fluvio- lacustrine

Lacustrine

Early basin fillAlluvial - lacustrine

Lithology

Sands, gravels, siltstone & mudstone,fluvial origin

Fluvio-lacustrine sandstone, siltstoneinterbedded with mudstone.

Fluvial channel sandstone andconglomeratic sandstone.

Intercalated sandstone, siltstone & mudstone.Lacustrine system with fluvial influence.

Mudstone with minor siltstone.

Conglomerate, sandstone interbeddedwith siltstone and minor mudstone.

Basement complex: clastics,carbonate rocks or metasediments.

Petroleum system

Reservoirs

Source andReservoirs

Source andReservoirs

Source

Source

Depth

Schematic stratigraphic sequence, Suphan Buri BasinSchematic stratigraphic sequence, Suphan Buri BasinSchematic stratigraphic sequence, Suphan Buri BasinSchematic stratigraphic sequence, Suphan Buri Basin

Adapted from Intharawijitr (1993)

Time(ms)

1 Km

N

Horizon D3

UT1-3

UT1-7

UT1-3/D

1

UT1-7/D2

560

630

700

770

840

910

980

1059

Time structuremap

Area = 37 sq. km.

TWT STRUCTURAL MAPTWT STRUCTURAL MAPTWT STRUCTURAL MAPTWT STRUCTURAL MAP

GR GR AIAI

Well UT1-7 Well UT1-3

mTVD

mTVD

Sub-unit D1

Sub-unit D2

Sub-unit D3

Sub-unit D5

Sub-unit D6

Sub-unit D4 OWCOWC

Wireline cross-plotsBelow OWC

Wireline cross-plotsAbove OWC

CONTENTS


GRAI

Shaly-sand

Sand

Shale

Wireline cross-plot: Wireline cross-plot: BelowBelow OWC OWCWireline cross-plot: Wireline cross-plot: BelowBelow OWC OWC

Low

High

Impedance (g/cc * m/s)

Gam

ma

ray

(A

PI)

-13UT

GRLLD

Wireline cross-plot: Wireline cross-plot: BelowBelow OWC OWCWireline cross-plot: Wireline cross-plot: BelowBelow OWC OWC

Gam

ma

ray

(A

PI)

Resistivity (ohm / m)

-13UT

Shaly-sand

Sand

ShaleGRAI

Wireline cross-plot: Wireline cross-plot: AboveAbove OWC OWCWireline cross-plot: Wireline cross-plot: AboveAbove OWC OWC

Low

High

Impedance (g/cc * m/s)

Gam

ma

ray

(A

PI)

-17

GRLLD

Wireline cross-plot: Wireline cross-plot: AboveAbove OWC OWCWireline cross-plot: Wireline cross-plot: AboveAbove OWC OWC

Gam

ma

ray

(A

PI)

Resistivity (ohm / m)

-17

WaveletWavelet

SyntheticSyntheticSeismicSeismic SyntheticSyntheticImpedance (g/cc*m/s)Impedance (g/cc*m/s)

WELL TO SEISMIC CORREL WELL TO SEISMIC CORRELATIONATION

WELL TO SEISMIC CORREL WELL TO SEISMIC CORRELATIONATION

CONTENTS


SEISMIC ATTRIBUTE ANALYSISSEISMIC ATTRIBUTE ANALYSIS

OWC

-126

126

SEISMIC ATTRIBUTE ANALYSISSEISMIC ATTRIBUTE ANALYSIS

Low

High

OWC

GR GR AIAI

Well UT1-7 Well UT1-3

mTVD

mTVD

Sub-unit D1

Sub-unit D2

Sub-unit D3

Sub-unit D5

Sub-unit D6

Sub-unit D4 OWCOWC

Wireline cross-plotsBelow OWC

Wireline cross-plotsAbove OWC

CONTENTS


INVERSE MODELLING FLOWCHARTINVERSE MODELLING FLOWCHART

Final AI result

Trace merge

Impedance(mid frequency)

Impedance(low frequency)

CSSI AI model

Solid earth modelAI

ConstraintsAI

Interpolation

WAVELETS SEISMIC LOGS TOPS HORIZONS FAULTS

AI log

ConstraintsTrend

IMPEDANCE TREND AND CONSTRAINTSIMPEDANCE TREND AND CONSTRAINTSIMPEDANCE TREND AND CONSTRAINTSIMPEDANCE TREND AND CONSTRAINTS

Well SK-1

INVERSE MODELING RESULTINVERSE MODELING RESULT

Low

High

20m

12m

18m

INVERSE MODELING RESULTINVERSE MODELING RESULTINVERSE MODELING RESULTINVERSE MODELING RESULT

Impedance(g/cc * m/s)

10000

10500

11000

11500

12000

12500

13000

13500

SAND

Sub-unit D6

Maximumimpedancedistribution

1 Km

N

UT1-3

UT1-7

UT1-3/D

1

UT1-7/D2

Sub-unit D5


1 Km

N


13500

10000

12000

12500

13000

10500

11500

11000

9500

SAND

UT1-3

UT1-7

UT1-3/D

1

UT1-7/D2


9500

9000

10000

10500

11000

11500

12000

12500

13000

SAND

Sub-unit D4


1 Km

N

UT1-3

UT1-7

UT1-3/D

1

UT1-7/D2

Sub-unit D3


1 Km

N


12500

13000

12000

11500

11000

10500

10000

9500

9000

SAND

UT1-3

UT1-7

UT1-3/D

1

UT1-7/D2

Generalized rift structure and sedimentation patternsGeneralized rift structure and sedimentation patternsGeneralized rift structure and sedimentation patternsGeneralized rift structure and sedimentation patterns

DELTAIC / FLUVIALSandstone + mudstone

Fan in footwall transfer zone

ALLUVIAL FAN / FAN DELTAConglomerate + sandstone

(Modified from Leeder and Gawthorpe 1987)

1 Km

N

FS

DL

Sub-unit D6

ImpedanceInterpretation FS

FC

FS

DL

Sub-unit D5

ImpedanceInterpretation

1 Km

N

LEGEND

FS

DL

Shale

Sand

Transportdirection

Fan / slump

Delta lobe

Feeder canyonFC

BF

C

DL

FS

Sub-unit D4


1 Km

N

LEGEND

FS

DL

Shale

Sand

Transportdirection

Fan / slump

Delta lobe

Channel

Basinfloor fan

C

BF

BF

C

DL

FS

FC

Sub-unit D3


1 Km

N

Axial delta lobe

Basinfloor fans

Axial channel

Max

imum

dis

plac

emen

t

Remnantrelay ramp

Max

imum

dis

plac

emen

t

Min

imum

dis

pl.

Fault linkage

Feeder canyons

N

1.50

Km

Fan or slump

SUMMARY GEOLOGICAL MODEL OF THE STUDY AREASUMMARY GEOLOGICAL MODEL OF THE STUDY AREASUMMARY GEOLOGICAL MODEL OF THE STUDY AREASUMMARY GEOLOGICAL MODEL OF THE STUDY AREA

CONCLUSIONS (1)

• Wireline impedance and seismic attributes responded primarily to lithology.

• Inverse modeling resulted in good comparison between wireline impedance and adjacent derived impedance traces, and enabled vertical sand resolution of about 12 m. • Maximum impedance extractions imaged two styles of sand distribution: axial and boundary fault induced deposits.

CONCLUSIONS (2)

• Axial deposits (delta lobes, channels and basinfloor fans) prograded from south to north downdip into the basin.

• Boundary fault induced deposits (fans / slumps and feeder canyons) showed two component pathways:

•Fans / slumps were transported perpendicular to the fault.•Feeder canyons transported sediment downslope to the NE.

• The basin architecture and sedimentation patterns agree with published general models of rift geology.

ACKNOWLEDGEMENTS

• PTT Exploration and Production Public Co. Ltd. for data & permission to present the results.

• Jason Geosystems and Landmark Graphic Corp. for software donation to the Department of Petroleum Geoscience, UBD.

• Jason Geosystems for technical support and review of this study.

PRESENTATION OVERVIEW

Acoustic impedance is used to map the Acoustic impedance is used to map the

locations and shapes of sand bodies locations and shapes of sand bodies

deposited within a producing fluvio-deposited within a producing fluvio-

lacustrine interval of a continental half lacustrine interval of a continental half

graben basin.graben basin.

Acoustic impedance is used to map the Acoustic impedance is used to map the

locations and shapes of sand bodies locations and shapes of sand bodies

deposited within a producing fluvio-deposited within a producing fluvio-

lacustrine interval of a continental half lacustrine interval of a continental half

graben basin.graben basin.

imaging sand distribution from acoustic impedance suphan buri basin, central thailand

Documents

geology wireline analysis

seismic inversion

grlldwireline crossplot

siltstone mudstone

minor mudstone

intercalated sandstone

minor siltstone

potential of wireline