Post on 01-Oct-2020
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Elastic 2D Modeling of Seismic Surveysof Seismic Surveys
Joe WongJoe Wong Peter Manning
Dave HenleyDave Henley
mFD2D - MATLAB software :
Designed for easy use;Models fairly complex geological structure;f y p g g ;Output data written to SEG-Y files.
Produce realistic-looking synthetic data for :g y f
Reflection RefractionRefraction VSP MicroseismicMicroseismic CrosswellTime LapseTime Lapse
Source Wavelets
Δx = Δz = 2.5 meters Δ 00025 dΔt =.00025 seconds
Vertical Comp.
R di l CRadial Comp.
Non-reflecting Surface
Free SurfaceFree Surface
Dyke –Fault Modely
Anticline Model
Fault-Fold Model
F l b d F l i D hFault bendfold
Fault propagationfold
Detachmentfold
Box foldPop-up
Duplex
STRUCTURES WEO G
Box fold
WANT TO IMAGEAntiformal stack
D. Spratt
Time Lapse Example
Finite Difference 2D Elastic Modeling
BEFORE:TARGET HAS HOSTTARGET HAS HOST ROCK PROPERTIES.
AFTER:10% DROP IN10% DROP IN TARGET PROPERTIES.
Baseline ModelBaseline Model
Monitor ModelMonitor Model
Baseline
Vertical Component
MonitorMonitor
Vertical Component DifferenceVertical Component Difference
Baseline
Radial Component
MonitorMonitor
Radial Component DifferenceRadial Component Difference
Relative Execution SpeedRelative Execution Speed
>> feature jit off>> feature jit off
MATLAB 2009a jit on 49 sec 1MATLAB 2009a jit on 49 sec 1MATLAB 2009a jit off 178 sec 3.6 MATLAB 2010b jit off 120 sec 2 4MATLAB 2010b jit off 120 sec 2.4MATLAB 2010b jit on 525 sec 10.7
Execution Time
Model size : 800 by 400 pixelsTime Steps : 4000No. of Shots : 100Run Time: 15 hours
Multi-processor operation :
Start 3 separate MATLAB windows.In each window run mFD2D from differentIn each window, run mFD2D from different folder names. In each window run same model withIn each window, run same model withinter-leaved shot points, orIn each window run a different modelIn each window, run a different model.
Wish List EnhancementsWish List Enhancements :
CPML d d fl tiCPML - decrease edge reflections ;Attenuation – seismic Q ;V l it A i t VTI/TTIVelocity Anisotropy - VTI/TTI ;Variable grid size ;R ti i ti (???)Reverse-time migration (???).
k l dAcknowledgement
This research was supported by NSERC d h i d i l f CREWSand the industrial sponsors of CREWS.