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Stacking Statics Residual statics in combination with the velocity analysis Muting Approximated zero offset section
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Stacking Statics Residual statics in combination with the velocity analysis Muting Approximated zero offset section.

Dec 22, 2015

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Page 1: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

Stacking Statics Residual statics in combination with the

velocity analysis Muting

Approximated zero offset section

Page 2: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

Delay-Time

GRM (“generalised reciprocal method”)

DRM (“diminishing residual matrices”)

Methods to determine the residual statics:

Statics (done before velocity analysis)

•Topographic Correction (elevation statics)

•“Uphole”-correction using shots in borehole

•Refraction statics: corrections for weathered layer

Page 3: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

CMP Gathers with field statics applied

1. Velocity analysis

NMO-Correction

Compute Residual statics

NMO-Correction with new Velocities

Stacking

Apply Residual statics

2. Velocity analysis

Residual statics

Page 4: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

NMO corrected data before and after residual corrections

Yilmaz, 1987

188297

Page 5: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

Velocity spectra before (a) and after (b) residual stacking

Page 6: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

CMP stacks without and with residual stacking

Yilmaz, 1987

Page 7: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

Mean stack

Weighted Stack

Diversity Stack/Min-Max-exclude

Certain traces are muted and not included in the stacking procedure

n

itimeant w

ns

1,,

1

n

itiiedmeanweightt w

ns

1,,

1

Methods to Stack

Page 8: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

stacked section

Page 9: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

Velocity model

Page 10: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

Velocity model

Page 11: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

Stacking velocity field

Yilmaz, 1987

Page 12: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

CMP stack

Yilmaz, 1987

Page 13: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

CMP stack using gain function

Yilmaz, 1987

Page 14: Stacking  Statics  Residual statics in combination with the velocity analysis  Muting  Approximated zero offset section.

Migrated CMP stack