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Welcome and overview of AASPI accomplishments and software development

Kurt J. Marfurt

Attribute-Assisted Seismic Processing and Interpretation

AASPI

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AASPI 2010 Sponsors

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• Ha Mai– (Ph.D. – Geophysics) – to PetroVietnam• Xavier Refunjol (M.S. Geophysics) – to Swift Energy• Victor Pena (M.S. Geophysics) – to BP• Rachel Barber (M.S. Geophysics) – to Devon• Jeremy Fisk (M.S. Geophysics) – now a cowboy• Marcilio Matos (Visiting scholar) - back home to Rio de Janeiro

AASPI 2010 Personnel Changes

• Araceli Romero (M.S. Geophysics)• Nabanita Gupta (Ph.D. Geology)• Yoryenys del Moro (M.S. Geophysics)• Toan Dao (M.S. Geophysics)• S. “Mike” Gao (M.S. Geophysics)

out

in

• Brad Wallet – (Ph.D. – Geophysics) – to Schlumberger• Kui Zhang – (Ph.D. Geophysics) – to BGP• Yanxia Guo – (M.S. Geophysics) – to BGP?• Amanda Thompson (M.S. Geophysics) – to Devon• Oz Elis (M.S. Geophysics - to TPAO• Ana Martins (M.S. Geophysics) – ???• Oz Elis - to TPAO • Alejandro Cabrales (M.S. Geophysics) – to PEMEX

going

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• Developed and released the following new attributes• Reflector convergence• Reflector rotation• Strike of most-positive and negative principal curvatures• Azimuthal intensity• Euler (apparent) curvature • Principal component analysis of multiple attributes (input to SOM)

• Prototyped the following new algorithms• Azimuthal anisotropy intensity, strike, and confidence• Prestack structure-oriented filtering on migrated gathers• Constrained least-squares prestack time migration (2D, 3D?)• Prestack data padding of migrated gathers• Phase residue mapping of unconformities• Self-organizing maps (most in Fortran90, some still in Matlab)

• Improved the following existing algorithms• Spectral decomposition (improved performance)• Structure-oriented filtering with spectral bands• Rose diagrams (now reads in principal curvatures and strikes)

AASPI 2010 Software Development

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• Use of acoustic impedance in AVAz analysis (Kui Zhang)

• 2nd derivatives (“curvature”) of acoustic impedance for fracture identification (Yanxia Guo)

• Calibration of curvature anomalies with outcrop analogues and image logs (Evan Staples)

• Correlation of production with fracture lineaments (Kui Zhang and Yanxia Guo)

• Correlation of P-wave anisotropy with induced fractures (Amanda Thompson and Kui Zhang)

• Correlation of attributes with sequence stratigraphy (Supratik Sarkar)

• Correlation of microseismic with impedance (Xavier Refunjol)

AASPI 2010 Workflow Development

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AASPI Software

AASPI Software

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Representative flow chart

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5/11/2010curvature3d_new

significant rewrite of the earlier curvature3d. All derivatives are now computed using a full 3D rather than 2D operator (for curvature) and 1D operator (for angular unconformities). To achieve efficient implementation, these operators are applied as multiplications in the vertical (time or depth) domain, as as convolutions in the space (x, y) domain. Files containing these operators for QC are also generated. Because of the greater number of samples involved, the results are smoother, such that the previous curvature3d value of alpha=0.25 now corresponds in curvature3d_new to a value of alpha=0.50 .

5/11/2010curvature3d_newazimuth of minimum curvature now computed along the dipping plane, and then projected onto the x-y plane as defined in the SEG abstract by Rich 2009

Jamie Rich, Devon Energy

5/11/2010curvature3d_new

azimuth of maximum curvature also computed along the dipping plane, and then projected onto the x-y plane as defined in the SEG abstract by Rich 2009. Previously, this attribute was not computed, since it was not independent (always perpendicular) to the previously naive computation of the azimuth of minimum curvature. The azimuth of maximum curvature remains perpendicular to the azimuth of minimum curvature in the dipping plane of the analysis point, but its projection on the x-y plane, will no longer be perpendicular except for flat dips.

Jamie Rich, Devon Energy

5/11/2010curvature3d_newrotation of reflector rotation now done in a 3D sense about the normal to the average dip within the analysis window.

5/11/2010curvature3d_new

the earlier (crude) 1D estimate of angular unconformities have been replaced by a more robust computation using the new 3D operators. The new attributes are inline_convergence, crossline_convergence, convergence_mag, and convergence_azim. These latter two attributes can be effectively plotted using program hlplot.

5/11/2010euler_curvaturea new application allowing generation of 'apparent' curvature at any user-defined azimuths. Currently, multiple output volumes are generated.

5/11/2010apparent_cmpta new application allowing generation of 'apparent' dip or apparent amplitude gradient at user-defined azimuths. Currently, multiple output volumes are generated.

5/11/2010sof3d_new

a new implementation of structure-oriented filtering that allows the user to define a suite of overlapping spectral pass-bands. Each pass-band undergoes structure-oriented filtering before reconstructing the filtered output. Optionally, the windowed rms amplitude of the output passbands can be balanced to approximate those of the input passbands using a traditional prewhitening value. This workflow mimicks that described by Helmore (2009) in his SEG expanded abstract paper.

5/11/2010image_filt3d now runs under MPI

5/11/2010image_filt3dnow applies the same kind of filters to the input confidence file, providing an updated estimate of the confidence in the dip estimates.

6/1/2010aaspi_util allow user-preference on pdf viewer of help files (was hard-coded to be gnupdf) Kevin Woller, Pioneer

7/1/2010curvature3d (old version)

fixed an error in the computation of k_mean. There was a term reading a*(0.0+e**2) that should have read a*(1.0+e**2) . This fat thumb error appears to have been there for quite some time. It was not in the curvature3d_new release. Kevin has a very good eye! Kevin Deal, Chevron

Bug reporting, fixes and updates

Coherence

Principal curvaturesStrike of Principal

curvatures

yes

Attributes based on volumetric dip and azimuth

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Seismic amplitude

Inline dip Crossline dip

Shape components Lineament volumes

Quadratic surface?

N

N

E

S

W

N

E

S

W

N

E

S

W

Mo

st-n

egat

ive

pri

nci

pal

cu

rvat

ure

, k2

Strike, ψk2

0 +90-90strong

weak

11

N

k2

ψk2

5 km

1.2

1.0

0.8

Tim

e (s

)

Strike modulated by most-negative principal curvature

12 (Seismic data courtesy of Devon Energy)

N

Coh

1.0

0.6

Amp

Positive

Negative

0

Strike vs. k2 Opacity

0 1

255

0

k2

ψk2

5 km

1.2

1.0

0.8

Tim

e (s

)

Strike modulated by most-negative principal curvature, co-rendered with coherence

13 (Seismic data courtesy of Devon Energy)

Coherence

Principal curvaturesStrike of Principal

curvatures

yes

Attributes based on volumetric dip and azimuth

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Seismic amplitude

Inline dip Crossline dip

Shape components Lineament volumes

Quadratic surface?

no

Reflector convergence

t=1.1 s

A

A’

N

Reflector convergence co-rendered with coherence

N

S

EW

Coh1.0

0.6

AmpPositive

Negative

0

0.6

0.8

1.0

1.2

1.4

1.6

1.8

Tim

e (

s)

A A’

B

B’

N

Reflector convergence co-rendered with coherencet=1.1 s

N

S

EW

Coh1.0

0.6

AmpPositive

Negative

0

0.6

0.8

1.0

1.2

1.4

1.6

1.8

Tim

e (

s)

B B’

C

C’

N

Reflector convergence co-rendered with coherence

N

S

EW

Coh1.0

0.6

AmpPositive

Negative

0

t=1.1 s 0.6

0.8

1.0

1.2

1.4

1.6

1.8

Tim

e (

s)

C C’

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Agenda