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3-D Migration Deconvolution: Real Examples. Jianhua Yu University of Utah Bob Estill Unocal. Outline. Motivation. 3-D Migration Deconvolution (MD). Examples. Conclusions. Outline. Motivation. 3-D Migration Deconvolution (MD). Examples. Conclusions. Unocal 3-D data from Alaska.
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3-D Migration Deconvolution: Real Examples Jianhua Yu University of UtahBob Estill Unocal
Outline Motivation 3-D Migration Deconvolution (MD) Examples Conclusions
Outline Motivation 3-D Migration Deconvolution (MD) Examples Conclusions
Unocal 3-D data from Alaska 2002 Winter: 3-D prestack time migration data
Mig in Inline (Courtesy of Unocal) MD 1.2 Times (s) 3.0
2003 Summer: 2003 Summer: 3-D prestack depth migration data 3-D prestack depth migration data Does MD work equally well for both time and depth migration? Unocal 3-D data from Alaska 2002 Winter: 3-D prestack time migration data
Apply 3-D migration deconvolution in depth domain Suppress migration noise and artifacts Improve spatial resolution Enhance illumination Objectives :
Outline Motivation 3-D Migration Deconvolution (MD) Examples Conclusions
T -1 R = (L L ) m MD efficiently eliminates the blurring influence in the migration image Migration Deconvolution Theory Migration Green’s function (Schuster and Hu, 2000)
Migration Green’s function (Schuster and Hu, 2000) Migration Deconvolution Theory
Velocity Acquisition geometry information Step 2: Calculate the migration Green’s function at the depth Zi MD Implementation Steps: Step 1: Prepare traveltime table
Migrated data True Reflectivity FFT of For the discrete MD equation:
Step 5: Repeat Steps 2-4 until the maximum depth is finished Step 6: IFFT of MD image from wavenumber domain to space domain Step 4: Obtain MD image at the depth Zi by solving following equation
Outline Motivation 3-D Migration Deconvolution (MD) Examples Conclusions
: source : Receiver 3-D Land Field Data
MD Mig (Courtesy of Unocal) Inline Number Inline Number 1 90 1 90 1 Crossline Number 300 (2 kft)
Crossline Number (Inline =50) 310 1 1.1 Depth (kft) Fault Fault 8
Mig MD Inline Number Inline Number 1 90 1 90 1 Crossline Number 265 (3.08 kft)
MD Inline Number Inline Number 1 90 1 90 1 Crossline Number 265 Mig (3.6 kft)
Mig (courtesy of Unocal) MD Inline Number 1 90 1 Inline Number 90 1.1 Depth (kft) 7.0 (Crossline=50)
Mig (courtesy of Unocal) MD Inline Number 1 90 1 Inline Number 90 1.1 Depth (kft) 7.0 (Crossline=50)
Mig in Inline (Courtesy of Unocal) MD 1.8 Times (s) 2.5
Mig (courtesy of Unocal) MD Inline Number Inline Number 1 90 1 90 1.1 Depth (kft) 8.0 (crossline 200)
Mig (courtesy of Unocal) MD Inline Number Inline Number 1 90 1 90 1.1 Depth (kft) 8.0 (crossline 200)
Y (kft) (X=11.2 kft) 15.5 1 1.1 Mig Depth (kft) MD 8.0
Outline Motivation Migration Deconvolution (MD) Implementation of MD Examples Conclusions
Little improvement in the deeper part of migration image MD cost is related to acquisition geometry Conclusions Improve resolution and suppress migration artifacts
Thanks To • Aramco, Unocal, and Chevron-Texaco for providing the field data • Alan Leeds (ChevronTexaco), and George Yao (Unocal) • 2003 UTAM sponsors • CHPC