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Published byGerald Hipps
Modified over 2 years ago
Making CMP’s From chapter 16 “Elements of 3D Seismology” by Chris Liner
Outline Normal Moveout Stacking
Normal Moveout x T Hyperbola:
Normal Moveout x T “Overcorrected” Normal Moveout is too large Chosen velocity for NMO is too (a) large (b) small
Normal Moveout x T “Overcorrected” Normal Moveout is too large Chosen velocity for NMO is too small (a) large (b) small
Normal Moveout x T “Under corrected” Normal Moveout is too small Chosen velocity for NMO is (a) too large (b) too small
Normal Moveout x T “Under corrected” Normal Moveout is too small Chosen velocity for NMO is too large (a) too large (b) too small
Vinterval from Vrms Dix, 1955
Vrms V1 V2 V3 Vrms < Vinterval
Vinterval from Vrms
Primary seismic events x T
Multiples and Primaries x T M1 M2
Conventional NMO before stacking x T NMO correction V=V(depth) e.g., V=mz + B M1 M2 “Properly corrected” Normal Moveout is just right Chosen velocity for NMO is correct
Over-correction (e.g. 80% Vnmo) x T NMO correction V=V(depth) e.g., V=0.8(mz + B) M1 M2 x T M1 M2
f-k filtering before stacking (Ryu) x T NMO correction V=V(depth) e.g., V=0.8(mz + B) M1 M2 x T
Correct back to 100% NMO x T NMO correction V=V(depth) e.g., V=(mz + B) M1 M2 x T M1 M2
Outline Convolution and Deconvolution Normal Moveout Stacking
NMO stretching V1 V2 T0T0 “NMO Stretching”
NMO stretching V1V1 V2V2 T0T0 “NMO Stretching” V 1
"name": "NMO stretching V1V1 V2V2 T0T0 NMO Stretching V 1
NMO stretching V1V1 V2V2 V 1
"name": "NMO stretching V1V1 V2V2 V 1
NMO stretching V1V1 V2V2 V 1
"name": "NMO stretching V1V1 V2V2 V 1
stretching for T=2s,V1=V2=1500 m/s Green line assumes V1=V2 Blue line is for general case, where V1, V2 can be different and delT0=0.1s (this case: V1=V2) Matlab code
Stacking + + =
+ + = Stacking improves S/N ratio
+ = Semblance Analysis “Semblance” + X Twtt (s)
+ = Semblance Analysis + X Twtt (s) V3V3 V1V1 V2V2 V Peak energy
Accommodation space, Coluvial wedge. Even in this image, throw is hard to interpret however, there is still geologic insight to be gained. Surface expression.
EXPLORATION GEOPHYSICS. EARTH MODEL NORMAL-INCIDENCE REFLECTION AND TRANSMISSION COEFFICIENTS WHERE: 1 = DENSITY OF LAYER 1 V 1 = VELOCITY OF LAYER.
T 2 = T X 2 /V 2. It is a hyperbola with apex at X = 0 and T 0 = 2H/V. – –V and H are the layer velocity and thickness. T 2 -X 2 plot is a straight.
Tom Wilson, Department of Geology and Geography Environmental and Exploration Geophysics II tom.h.wilson Department of Geology.
Processing and Binning Overview From chapter 14 “Elements of 3D Seismology” by Chris Liner.
Reflection seismograms Each reflection will follow a moveout trajectory according to the moveout equation.
Geology 5640/6640 Introduction to Seismology 3 Apr 2015 © A.R. Lowry 2015 Last time: Reflection Seismic Equations for a reflection two-way travel-time.
The Experimental Comparison of Conventional and Differential Semblance on several data sets Jintan Li Rice University.
Loading of the data/conversion Demultiplexing Editing Geometry Amplitude correction Frequency filter Deconvolution Velocity analysis NMO/DMO-Correction.
Processing: zero-offset gathers
Velocity Analysis Introduction to Seismic ImagingERTH 4470/5470 Yilmaz, ch
Basic Seismic Processing INPUT FILTER CMP Gather NMO STACK MIGRATE DISPLAY GEOM VEL ANAL STATICS MUTE.
Primary-Only Imaging Condition Yue Wang. Outline Objective Objective POIC Methodology POIC Methodology Synthetic Data Tests Synthetic Data Tests 5-layer.
Introduction to Seismic Reflection Imaging References: J.M. Reynolds, An Introduction to Applied and Environmental Geophysics, John Wiley & Sons,
Processing Seismic Reflection Data of La Bajada Fault Ryan Lester.
Impact of MD on AVO Inversion
Geology 5660/6660 Applied Geophysics 10 Feb 2016 © A.R. Lowry 2016 Last Time: Seismic Reflection Travel-Time Cont’d Dix Equations for multiple layers:
Radon Transforms in Tau-P space and Multiple Removal.
GG450 April 22, 2008 Seismic Processing.
Super-virtual Interferometric Diffractions as Guide Stars Wei Dai 1, Tong Fei 2, Yi Luo 2 and Gerard T. Schuster 1 1 KAUST 2 Saudi Aramco Feb 9, 2012.
Seismic Reflection Data Processing and Interpretation A Workshop in Cairo 28 Oct. – 9 Nov Cairo University, Egypt Dr. Sherif Mohamed Hanafy Lecturer.
Seismic Reflection: Processing and Interpretation Katie Wooddell UW Madison.
Seismic reflection Ali K. Abdel-Fattah Geology Dept.,
Yue Du Mark Willis, Robert Stewart AGL Research Day
SOES6004 Data acquisition and geometry
Occurs when wave encounters sharp discontinuities in the medium important in defining faults generally considered as noise in seismic sections seismic.
GG 450 April 16, 2008 Seismic Reflection 1.
Geology 5660/6660 Applied Geophysics 12 Feb 2016 © A.R. Lowry 2016 For Fri 14 Feb: Burger (§ ) Last Time: Seismic Reflection Travel-Time.
Migration In a Nutshell Migration In a Nutshell Migration In a Nutshell D.S. Macpherson.
Filters Temporal Fourier (t f) transformation Spatial Fourier (x k x ) transformation applications f-k x transformation Radon (-p x ) transformation.
Refraction Statics Bryce Hutchinson Sumit Verma. 3D Statics display 1. Click this button on the right side of the statics window to open a 3D statics.
The ray parameter and the travel-time curves P flat and P radial are the slopes of the travel time curves T-versus-X and T-versus- , respectively. While.
Multisource Least-squares Reverse Time Migration Wei Dai.
Geology 5660/6660 Applied Geophysics Last time: The Refraction Method Cont’d Multiple Horizontal Layers: Using Snell’s law, generalizes simply to: Dipping.
Time vs Depth Migration Insensitive to v(z) model Sensitive to v(z) model Time migration uses best fit hyperbola Depth migration uses best guess moveout.
Seismic Reflection Processing Illustrations The Stacking Chart and Normal Moveout Creating a seismic reflection section or profile requires merging the.
Introduction to GeoProbe
Velocity Picking Bryce Hutchinson Sumit Verma Objectives : 1. Be able to understand semblance, supergather, CVS 2. Recognize under corrected, over corrected,
5. Seismology William Wilcock OCEAN/ESS 410. A. Earthquake Seismology.
Lee M. Liberty Research Professor Boise State University.
I. Basic Techniques in Structural Geology
MULTIPLE PREDICTION & ATTENUATION Ruiqing He University of Utah Feb Feb
Land and Marine Seismic Acquisition from 2D to 3D
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