References - GeoScienceWorld

189

References

Bahorich, M., and S. Farmer, 1995, 3D seismic discontinuity for faults and stratigraphic features: The coherence cube: The Leading Edge, 14, 1053–1058.

Barnes, A. E., 2007, Redundant and useless seismic attributes: Geophysics, 72, no. 3, P33–P38.

Bertram, G. T., and N. J. Milton, 1996, Seismic stratigraphy, in D. Emery and K. J. Meyers, eds., Sequence stratigraphy: Blackwell Scientific, 45–60.

Brown, A. R., 1996, Seismic attributes and their classification: The Leading Edge, 15, 1090.

Brown, A. R., 2011, Interpretation of three-dimensional seismic data, 7th ed.: AAPG Memoir 42 and SEG Investigations in Geophysics No. 9.

Calvert, R., 2005, Insights and methods for 4D reservoir monitoring and characterization: SEG/EAGE Distinguished Instructor Series No. 8.

Chopra, S., and K. J. Marfurt, 2007, Seismic attributes for prospect identification and reservoir characterization: SEG.

Chun, J. H., and C. A. Jacewitz, 1981, Fundamentals of frequency domain migration: Geophysics, 46, 717–733.

Dix, C. H., 1952, Seismic prospecting for oil: Harper & Brothers.———, 1955, Seismic velocities from surface measurements: Geophysics, 20,

68–86.———, 1984, Interview with TLE editor Robert Dean Clark: The Leading Edge,

3, 14–17.Ebaid, H., A. Tura, M. Nasser, P. Hatchell, F. Smit, N. Payne, D. Herron, D. Stanley,

J. Kaldy, and C. Barousse, 2008, First dual-vessel high-repeat GoM 4D survey shows development options at Holstein field: The Leading Edge, 27, 1622–1625.

Etgen, J., S. H. Gray, and Y. Zhang, 2009, An overview of depth imaging in exploration geophysics: Geophysics, 74, no. 6, WCA5–WCA17.

Feynman, R. P., 1985, Surely you’re joking, Mr. Feynman!: Bantam Books.Gould, S. J., 1993, Eight little piggies: W. W. Norton & Co.———, 1995, Dinosaur in a haystack: Harmony Books.Gray, S. H., J. Etgen, J. Dellinger, and D. Whitmore, 2001, Seismic migration

problems and solutions: Geophysics, 66, 1622–1640.

SEG-SEISMIC-11-0601-REF.indd 189 05/12/11 2:18 PM

Downloaded from http://pubs.geoscienceworld.org/books/book/chapter-pdf/3783875/9781560802938_backmatter.pdfby gueston 25 January 2022

190 First Steps in Seismic Interpretation

Hardage, B. A., M. V. DeAngelo, P. E. Murray, and D. Sava, 2011, Multicomponent seismic technology: SEG Geophysical Reference Series No. 18.

Hart, B. S., 2011, An introduction to seismic interpretation: AAPG Discovery Series No. 16, CD-ROM.

Hawking, S., and L. Mlodinow, 2010, The grand design: Bantam Books.Herron, D. A., 2000a, Horizon autopicking: The Leading Edge, 19, 491–492.———, 2000b, Pitfalls in seismic interpretation: Depth migration artifacts: The

Leading Edge, 19, 1016–1017. ———, 2001, Problems with too much data: The Leading Edge, 20, 1124–1126.———, 2003, Characteristics of an interpreter: The Leading Edge, 22, 49.———, 2009, Interpreting depth-imaged data: Case studies, examples and pitfalls

from the interpreters’ perspective: The Leading Edge, 28, 364–367.Hilterman, F. J., 2001, Seismic amplitude interpretation: SEG/EAGE Distinguished

Instructor Series No. 4.Lindseth, R. O., 1979, Synthetic sonic logs — A process for stratigraphic

interpretation: Geophysics, 44, 3–26.Mitchum, R. M., Jr., 1977, Glossary of terms used in seismic stratigraphy, in C. E.

Payton, ed., Seismic stratigraphy — Applications to hydrocarbon exploration: AAPG, 205–212.

Mitchum, R. M., Jr., P. R. Vail, and J. B. Sangree, 1977, Stratigraphic interpretation of seismic reflection patterns in depositional sequences, in C. E. Payton, ed., Seismic stratigraphy — Applications to hydrocarbon exploration: AAPG, 117–133.

Nettleton, L. L., 1940, Geophysical prospecting for oil: McGraw-Hill Book Company.

Ogilvie, J. S., and G. W. Purnell, 1996, Effects of salt-related mode conversions on subsalt prospecting: Geophysics, 61, 331–348.

Orwell, G., 1946, Politics and the English language: Harcourt.Payton, C. E., ed., 1977, Seismic stratigraphy — Applications to hydrocarbon

exploration: AAPG. Pennington, W. D., A. Minaeva, and S. Len, 2004, Uses and abuse of “phantom

horizons”: The Leading Edge, 23, 454–456.Petroski, H., 1992, To engineer is human: The role of failure in successful design:

Vintage Books.———, 2008, Success through failure: The paradox of design: Princeton University

Press.Sheriff, R. E., 2002, Encyclopedic dictionary of exploration geophysics, 4th ed.:

SEG Geophysical Reference Series No. 1.Shuey, R. T., 1985, A simplification of the Zoeppritz equations: Geophysics, 50,

609–614.Tucker, P. M., 1982, Pitfalls revisited: SEG Geophysical Monograph Series No. 3.———, 1988, Seismic contouring: a unique skill: Geophysics, 53, 741–749.



References 191

Tucker, P. M. and H. J. Yorston, 1973, Pitfalls in seismic interpretation: SEG Geophysical Monograph Series No. 2.

Tufte, E. R., 2001, The visual display of quantitative information: Graphics Press LLC.Vail, P. R., R. G. Todd, and J. B. Sangree, 1977, Seismic stratigraphy and global

changes of sea level, part 5 — Chronostratigraphic significance of seismic reflections, in C. E. Payton, ed., Seismic stratigraphy: Applications to hydrocarbon exploration: AAPG, 99–116.

Wikipedia, Accuracy and precision, accessed 15 June 2011, http://en.wikipedia.org/wiki/accuracy_and_precision.

Yilmaz, O., 2001, Seismic data analysis: Processing, inversion, and interpretation of seismic data: SEG Investigations in Geophysics No. 10.



http://en.wikipedia.org/wiki/accuracy_and_precision

http://en.wikipedia.org/wiki/accuracy_and_precision

This page has been intentionally left blank


193

Index

A

accuracy, as distinguished from precision, 175–176 (see also precision, as distin-guished from accuracy)

acoustic impedance (AI), 4, 5, 9, 22, 30, 31, 34, 117, 166

and density logs, 117and properties of layers, 30and reflection-coefficient

(RC) series, 30, 31, 117and sonic logs, 117calculation from reflection-

coefficient series, 34magnitude and algebraic

sign, 22measurable change, posi-

tive, 166reflection coefficient, 22

acoustic-impedance (AI) bound ary, 9, 10

seismic pulse incident to, 10and structural interpreta-

tion, 23acoustic-impedance (AI)

function, and reflection-coefficient (RC) series, 30, 31

AI (see acoustic impedance)air gun, 38aliasing, 75, 76, 79, 80amplitude, 22–28

above-background ampli-tude, 24

acoustic-impedance bound-ary, magnitude and alge-braic sign, 22

acoustic-impedance boundary, reflection coefficient, 22

and convolutional model, 22and dominant frequency, 27and gain recovery, 23and manifestation of geol-

ogy, 24and quantitative analysis, 23and reflection-coefficient

series, 22and seismic facies analysis,

26and sequence stratigraphy, 26and stacking, 23and time-amplitude (tuning)

analysis, 26autotracking, 24average absolute amplitude,

25balancing, 23baseline value, 22convolutional model, 22ΔA, delta amplitude, 22ΔT, delta time, 22maximum positive ampli-

tude, 25quantitative use of, and

picking of reflections, 24root-mean-square (rms)

amplitude, 25amplitude anomalies, 24, 115

highlighting, 24amplitude balancing, 23amplitude spectra, 15amplitude variation with angle

of incidence (AVA), 49, 112

amplitude variation with offset (AVO), 32, 49, 112

amplitudes, misinterpreted, and misestimated wavelet phase, 112–113

angular unconformity, 93

anisotropic depth-imaged data, 57, 111

anisotropic prestack depth migration (APSDM), 57, 58

anisotropy, 56 (see also veloc-ity anisotropy)

polar, 56 (see also polar anisotropy)

vertical transverse, 56tilted transverse, 56

antialias filter, 75anticlines, 109, 110apophenia, 109apparent-dip 2D migrated

seismic lines, and time migration, 128

approximation and thinking, 175

approximations, 174–176artifacts, and interpretation

pitfalls, 105–113categories, 105coherent noise, misinter-

preted as primary signal, 106–109

correlation, 106detection of, 113false time structures inter-

preted as real depth structures, 109–112

noise interpreted as discon-tinuous signal, 109

partial stacks and nonrecog-nition of high-coherence events, 112

seismic artifacts, recognition of, 105

wavelet phase misestimated and amplitudes misinter-preted, 112–113

SEG-SEISMIC-11-0601-IDX.indd 193 06/12/11 7:30 PM



attenuation, 11, 27and distance, 11and dominant frequency, 27correction of, determinis-

tic, 11correction of, probabilistic, 11

attribute, seismic, 21automatic gain control (AGC), 23

and structural interpreta-tion, 23

automatic tracking, versus manual tracking (see tracking, manual versus automatic)

autotracking, 24, 27, 29, 96– 104, 121, 139, 151

average absolute amplitude, 25average velocity, 61AVO/AVA effects, 50

B

balancing and decompaction, 136

bandwidth, 13baseline survey, 165basement, 19, 20beam-migration depth-migra-

tion method, 72bias, 6bin size, and spatial sample

rate, Δx, 81biostratigraphic data, 116block diagrams, 149bottom-simulating reflection

(BSR), 107boundaries, subsurface, reflec-

tions, use of, conditions, 19–20

and visual estimation of wavelet phase, 19–20

bow-tie reflection, 66, 68Brazil, 71bright spots, 24buried focus syncline, 69

C

calibrated velocity model, for vertical conversion of points, 59

causal wavelets, 15CDP (see common depth point)

CDP gathers, 47, 48, 49Cenozoic basins, 24channel, 100, 101, 115channel margins, 28check-shot survey, 38, 39,

40, 60compared with vertical seis-

mic profile, 40circular wavefronts, and con-

stant-velocity migrations, 124

clipping values, 23CMP (see common midpoint)coherence, 28–30

and channel margins, 28and coherence slices, 29and coherence volume, 28and faults, 28, 29and noise, 28and 3D seismic data, 28

coherence data, and faults, 87coherence horizon slice, 29coherence slices, 133coherence time slice, 29coherence volume, 28–29, 30

and data-analysis window, 28reflectivity volume, and

faults, 30coherent noise, 106, 107

crosscutting primary reflec-tions, 107

interpreted as primary sig-nal, 106

color table, 116common-azimuth depth-migra-

tion method, 72common depth point (CDP),

43, 44, 47, 48, 49gather, 44, 47, 48, 49method of acquisition,

model of, 43common-depth-point interval,

and spatial sample rate, Δx, 81

common-depth profiling, 1common midpoint (CMP),

43, 44compaction of reservoirs, 166composite seismic response and

reflection coefficients, 18composite seismic responses,

accurate interpretation and source wavelets, 18

compressional-wave reflec-tions, 9

constant-velocity migrations and circular wavefronts, 124

continuous velocity model, for vertical conversion of points, 59, 61

contouring (see gridding and contouring)

convolution, 16and simulation of propaga-

tion of seismic pulse, 16of reflection-coefficient

(RC) series, 16convolutional model, 16–18, 22

composite response, and interference, 16–17

scaled wavelet, 16seismic response to reflec-

tion coefficient, 16cores, 116corrected gathers, inspection,

before partial stacking, 50correlation, and depth-migra-

tion projects (see depth-migration projects)

correlation, jump (see jump correlation)

correlation, processes and tech-niques that control data quality, 183

correlation ambiguity, 132correlation concepts, 83–113

artifacts and interpretation pitfalls, 105–113

coherent noise interpreted as primary signal, 106–109

false time structures inter-preted as real depth structures, 109–112

first look, 83–84horizons versus faults,

84–93manual tracking versus

automatic tracking, 96–104

multiple reflections, 94–96noise interpreted as discon-

tinuous signal, 109partial stacks and nonrecog-

nition of high-coherence events, 112



Index 195

wavelet phase misdeter-mined and amplitudes misinterpreted, 112–113

correlation of seismic records, 4, 5

and most common intellec-tual difficulty, 5

and pattern recognition, 4correlation polygon, 133, 134,

137correlation procedures,

115–151depth-migration projects,

correlations, 140–145interpretation processes and

work flows, 149–150jump correlation, 120,

133–139loop tying, 120, 121–133reflection seismic data, pro-

cedures, 120visualization, 145–149

cosine wave, 12, 13and sine wave, phase rela-

tionship, 13as function of time, 12shape of waveform, vari-

ables in, 12crosscutting coherent noise,

108cuttings, 116

D

data, phase of, description, 15data acquisition and process-

ing, as related to seismic interpretation, 5

data management, 158–159 (see also data quality, and data management)

data quality, and data manage-ment, 153–161 (see also data management; data quality, responsibility for assessment)

and depth-migration proj-ects, 158

and detection, 155and image fidelity, 155–156and resolution, 155–156assessment of, 153data quality, 153–158

data-quality maps, 156–157nomenclature systems, 159–

161power of data set, 155primary elements of, 155quantitative measurement

of, 154relative to purpose of data,

153–155resolution, 155“traffic-light” map, 156–157variation, mapping of, 156

data quality, responsibility for assessment, 3 (see also data management)

data-quality maps, 156–157decompaction and balancing,

136δ, Thomsen parameter, and

short-offset moveout correction, vertical veloc-ity, 56

ΔA (delta amplitude), 22, 23, 26

and time-amplitude analy-sis, 26

and tuning analysis, 26ΔT (delta time), 22, 23, 26

and time-amplitude analy-sis, 26

and tuning analysis, 26Δti (two-way-time thickness,

ith layer), 36Δx (spatial sample rate), 2D

and 3D seismic lines, 81relative to bin size, 81relative to common-depth-

point interval, 81relative to sampling wave-

number, 81Δzi (thickness, ith layer), 36demultiple processing, 95, 172density logs, 117, 118

and reflection-coefficient (RC) series, 117

and synthetic seismogram, 118

depositional systems, 26depth domain, 43depth gathers, 112depth imaging, 58, 70, 169

and isotropic models, 58failure of, conditions, 70

inaccurate, manifestation of, 169

depth-imaging domain, pitfalls, 111

depth migration, 57, 70–71, 73, 91, 173

and correction for velocity anisotropy, 57

and time migration, differ-ences, 70–71

artifacts, and faults, 91methods, migration algo-

rithms, 72depth-migration artifacts, 91, 168depth-migration processing

sequence, marine 3D data, subsalt exploration, 140

final migration, and imaging subsalt section, 140

salt-flood migration, and imaging base of salt, 140

sediment-flood migration, and imaging top of salt, 140

waterflood migration, and imaging of seafloor, 140

depth-migration projects, 140–145, 158

and data management, 158and subsalt exploration, 140correlations in, 140–145depth-migration processing

sequences, steps in, 140final migration, and imaging

subsalt section, 140salt-flood migration, and

imaging base of salt, 140sediment-flood migration,

and imaging top of salt, 140


detection, 3, 155diagenesis, 175difference survey, 166dip, 87dip line, time-migrated, 123direct hydrocarbon indicator

(DHI), 24display formats, reflection seis-

mic data, 15, 16, 17display lines, 117




distortion, inevitability of, 83Dix equation, 51, 53

conditions for valid applica-tion of, 53

Dix interval velocities, 54, 55example, 55sensitivity, to stacking-

velocity picks, 54Dix interval-velocity calcula-

tion, sensitivity, illus-trated, 54

Dix’s correlation procedure, in modern seismic interpre-tation, 2

Dix’s threshold of impossibil-ity, 106

domain of information, 4dominant frequency, 27, 28, 76,

78, 79and attenuation, 27and depth-domain data, 28and time-domain data, 28and tuning thickness, 76calculation of, 27, 28

double multiple, 94, 95, 96, 97, 98

E

80-20 rule, 120, 185elastic medium and seismic

pulse, 100elastic waves, 9ε (Thomsen parameter), 57ergonomics, 179–180η (Thomsen parameter), and

deviation of long-offset P-wave moveout, 56

evidence, rules of, 2extensional fault, 122, 123

F

f (dominant frequency, seismic signal), 79, 81

false time structures, 109–112, 116

fault block, 133fault correlations, 131–133

and coherence slices, 133and horizontal reflectivity

slices, 133

fault cuts, 139comparing, to identify mis-

correlations, 139fault heaves, 104fault picks, aliasing of, 131faults, 28–30, 68, 69, 84–93,

94, 116, 117, 119, 120, 122, 123, 131, 133, 136, 138, 168

accurate positioning of, 131and coherence data, 87and depth-migration arti-

facts, 91, 168and tents, 131correlating, concerns in, 86faults versus horizons, 84–93interpretation of, 119listric normal, 90normal, 86, 131, 136, 138reverse, 86, 90, 136, 138tracking of, 85–862D and 3D data, compared,

86fence diagrams, 149first arrival, 39flat spot, seismic, 19, 20fold of coverage, 43fold of data, volume of data,

and reduction in stack-ing, 49

foreshortened perspective, for viewing data, 146, 147, 148, 149

formalities, titular, recom-mended abandonment of, 182

forward seismic modeling, 167, 174

4D seismic (time, and three spatial dimensions), 165–167

amplitude-attribute analysis of, differences, 166

baseline and monitor sur-veys, 165

compaction, 166difference survey, 166fluid saturation, variation

of, 166geomechanical changes, 166“hardening” of reservoirs, 166impedance changes, analysis

of, 166

interpretation and analysis, 166

overburden, stretching of, 166

pore pressure, variation of, 166

purpose, 165requirements, 165“softening” of reservoirs,

1664D time-shift effects, 166Fourier analysis, 11, 13

and waveform phase, 13Fresnel zone, 78

and spatial resolving power, seismic data, 78

geometry, 78measurement, 78

frowning events, 46

G

gain recovery, 23gambler’s ruin, 186gas breakout, 166gas-charged sediments, 110gas hydrate stability zone

(GHSZ), 107, 108Gulf of Mexico, 108

gates, and reflections, 24geochemical data, 116geology, value of, in geophys-

ics, 182ghost multiples, 95gridding, 121gridding and contouring,

163–165gridding programs, and

subjective elements of geology, 164

manual operations, merits of, 164–165

purposes, 163ground truth, 184Gulf Coast, 119Gulf of Mexico, 108, 166

H

“hardening” of reservoirs, 166high-amplitude response and

hydrocarbon-charged sand, 136



Index 197

horizon, 10, 84–85horizon autotracking, 139horizon identification, wildcat

exploration compared with production proj-ects, 10

horizon names, 160–161horizon time, 21horizons, 84–93, 94, 136, 160

components, 160picking, 93, 136versus faults, 84–93

horizontal reflectivity slices, 133

hydrocarbon migration, 175hydrocarbon/water contact,

19, 108for estimation of wavelet

phase, 19hypotheses, working, 170–174

I

illumination, 49, 70–73image fidelity, 3, 156imaging accuracy, 2D data

compared with 3D data, 66, 69

imaging artifacts, 94, 170impedance changes, analysis

of, prestack domain, 166implicit uncertainty, data acqui-

sition and imaging, 133impossibility, threshold of, 2inclined reflector and two

orthogonal 2D time-migrated lines, mis-tie, 129–130

interpretation, 1, 2, 184–185advanced, 184–185and seismic data quality, 2

interpretation paradox, 174interpretation pitfalls (see arti-

facts, and interpretation pitfalls)

interpretation processes and work flows, 149–150

generic interpretation, 149, 151

granularity in work flow, 149processes, summary of, 150

interval transit time (ITT), 36, 37, 53

and interval velocity, 36, 37and the term “slowness,” 36

interval velocity, 36, 37, 39, 51, 53, 55, 60, 61, 62

and interval transit time, 36, 37

calculated from stacking velocities, 55

calculated with Dix equa-tion, 53, 62

calculation, 39, 51model, layered, 60

intrusions, 117inverse seismic modeling, 167inversion, 30–34

and quality of data acquisi-tion and processing, 32

and synthetic sonic log, 32and time domain, 32assumptions about process-

ing input reflectivity data, 32

correlation of, compared with conventional reflec-tivity data, 32–33

relative to acquisition-pro-cessing-interpretation, reflection seismic data, 30

inverted data, scaling of, 32isotropic depth-imaged data

and Z-to-D correction, 111

J

jump correlation, 115, 131, 133–139, 168, 170

and correlation polygon, 133and fault blocks, 133–134and pattern recognition, 133and tunnel vision, 134common use of, 133flattening, on correlated

horizon, 134–135

K

k (wavenumber), relative to wavelength, 81

Kirchhoff multiarrival depth-migration method, 72

Kirchhoff single-arrival depth-migration method, 72

L

lag, 12λ (wavelength), 76, 81

relative to wavenumber, k, 81layered interval-velocity model, 60layered velocity model, for

vertical conversion of points, 59

lead, 12limestone, 119limitations, necessity of under-

standing, 2line ties by reflection character,

122–126lines, mis-tied, critical factor, 125listric normal fault, 90, 122, 123

dip and strike views, 90long-wavelength structures, 112loop, 121loop tying, 115, 120–133

and 3D data, 121–122and faults, 120

M

map migration, 65, 131and subsurface reflecting

points, positioning of, 131maximum positive amplitude, 25migration, 4, 63–73, 116, 170

algorithms, matrix of, for variations in complexity of subsurface geology, 72

and dip-field complexity, 72and multipathing waves, 72and velocity complexity, 72artifacts, 170for structure, simple or com-

plex, 69for velocities, simple or com-

plex, 69map migration, 65purpose, 63steep/overturned reflec-

tors, 72time domain compared with

depth domain, 69types of, for prestack and

poststack depth domains, 69

migration, of hydrocarbons, 175




migration swings, interpreted as primary signal, 106

migration velocities, differ-ences between, 130

migration velocity model, 116mis-tie, 122, 123

2D data, 122mis-tied lines, critical fac-

tor, 125 (see also time migration; time migra-tion and apparent-dip 2D migrated seismic lines)

mis-ties caused by differences in acquisition and pro-cessing, 130

mode-converted waves, subsalt exploration, 173

model-based interpretation, 6monitor survey, 165moveout-corrected CDP gath-

ers, 47, 48, 49moveout-corrected traces,

stacking, and noise reduction, 45

moveout correction, as related to velocity, 46

moveout velocities, and errors in stacked traces, 46–47

multifold acquisition, 42multifold coverage, and con-

ventional seismic veloc-ity analysis, 42

multiple reflections, 94–96, 97, 98

common multiples, 95demultiple processing, 95double multiple, 94, 95, 96,

97, 98ghost, 95long-period, 94peg-leg, 95, 96, 97period, 94positions of, prediction,

96, 97recognition of, 96short-period, 94

multiple velocity functions, for vertical conversion of points, 59

multiples, 94, 106, 172interpreted as primary sig-

nal, 106

multivalued horizon capability, of workstation system, 141

N

NMO (see normal moveout)NMO-corrected gathers, 54noise, 106, 109

coherent, interpreted as primary signal, 106

interpreted as discontinuous signal, 109

nomenclature systems, 159–161attributes, 159horizon names, core elements

and purposes, 160–161horizons, components, 160importance, 159requirements of, 159

noncausal wavelet, 13, 15and causal wavelet, 15

normal hyperbolic moveout, 45normal-incidence reflection,

point of, 64normal moveout (NMO), 43–45

correction, 45equation, 43, 44traces, stacking, and noise

reduction, 45normal-moveout (NMO) veloc-

ity, 45, 57and correction for velocity

anisotropy, 57and stacking velocity, Vstk, 45

Nyquist frequency, 75, 76Nyquist theorem, 75, 78, 81,

121, 164Nyquist wavelength, and sam-

pling wavenumber, 81Nyquist wavenumber, and sam-

pling wavenumber, 81

O

observe-interpret-test cycle, 6oil-water contacts, tilted, 19onland data, 116optimal stacking velocity,

42– 43orthogonal 2D time-migrated

lines, tying, 125, 127– 129

overburden, stretching, 166overpressured sediments, 110

P

partial stacking, purpose, 49partial stacks, and nonrecogni-

tion of high-coherence events, 112

particle motion as function of time, and seismic wave-form, 11

particle motions, positive and negative reflection pro-cesses, 11

pattern recognition, and cor-relation of seismic records, 4

peg-leg multiples, 95, 96, 97, 106, 107, 172, 173

phantom horizons, 119phase, 10 (see also wavelet

phase)phase lag, 12phase rotation, 13, 34

and inversion of reflectivity data, 34

phase spectra, 15pitfalls, interpretation (see arti-

facts, and interpretation pitfalls)

plate convergence, 175polar anisotropy, 56 (see also

anisotropy, defined, polar)

and reflection seismic data, 56and vertical transverse isot-

ropy (VTI), 56characterization, and Thom-

sen parameters, 56polarity, 10polarity reversals, 106pore pressure, variation, and

impedance, 166poststack depth migration

(PoSDM), 69poststack time migration

(PoSTM), 69power, of data set, 155precision, as distinguished from

accuracy, 175–176 (see also accuracy, as distin-guished from precision)



Index 199

presentations, 180–181requirements, 180–181

prestack depth migration (PSDM), 57, 58, 61, 69, 91, 92, 98, 110, 111, 168, 169

and Z-to-D vertical correc-tion, 57

isotropic, and migrated velocities, 57

line, 169velocity model, 98, 111volume, 168

prestack time migration (PSTM), 69

primary reflection, 94, 95principal component analysis, 21probability of success, 177problem solving, 182PSDM (see prestack depth

migration)pull-up, and shallow salt, 116pulse width, 17P-wave conversion to S-wave,

173P-wave energy, 173P-wave reflections, 9

Q

qualitative assessments, and quantitative expressions, 177

quality, 2–3 (see also seismic data quality)

of data, determinants in, 4

R

Rayleigh limit, vertical resolu-tion, 76, 79

rays, 64reflection and reflector, distin-

guished, 11reflection coefficient (RC), 4, 5,

9, 16, 18and composite seismic

response, 18defined in terms of AI, 9responses, 18

reflection-coefficient (RC) series, 16–18, 22, 30–31, 34, 117

and acoustic-impedance data, 117

and four coefficients, 16and properties of layers, 30as derivative of AI function,

assumptions, 30–31as distinguished from reflec-

tivity data, 30convolved with zero-phase

wavelet, 16, 18derivative of AI function,

assumptions, 31reflection seismic data, 15, 16,

120composite response to

boundaries, 16correlation, procedures, loop

tying and jump correla-tion, 120

display formats, 15variable density, 15

reflection times, manual record-ing, 165

reflections, multiple, 94–96reflections, ties, 3D data, mi-

grated, 122reflectivity data, correlation,

compared with correla-tion, seismic inversions, 32, 33

reflectivity data, zero-phase, 32–33

reflectivity volume, coherence volume, and faults, 30

reflector and reflection, distin-guished, 11

refraction, of seismic energy, 70reservoir engineering, 183resolution, 3, 75–81, 155–156

aliasing, 75, 76and Nyquist theorem, 75, 78antialias filter, 75resolvable limit, 156sampling frequency, 75sampling, specified, 75

resolvable limit, for discrete seismic reflectors, 156

reverse fault, dip and strike views, 90

reverse time depth-migration method, 72

risk, and uncertainty, 176–178and geologic models, 177

and risk, quantitative expres-sion of, 177, 178

and symmetry of estimate, 177

qualitative assessments and quantitative expressions, 177

risking systems and risk factors, 178

uncertainty, and aspects free of implication about accuracy, 176

uncertainty, and implication about accuracy, 176

uncertainty, common mea-sure of, 177

uncertainty, relative to preci-sion of measurement, 176

risk assessment and seismic data quality, 178

rock velocities, error in mea-surement, sources, 38

root-mean-square (rms) ampli-tude, 25

root-mean-square (rms) veloc-ity, 39, 62

rotation of image, 146

S

salt, 19, 20, 60, 67, 70, 91, 97, 98, 101, 109, 110, 116, 140, 141–144, 145

and pull-up, 116and salt-flood migration,

140base-of-salt reflection, 101closed bodies, top and base,

picking, technique, 141–143, 144

correlation, top and base, accuracy, 140

sutures, 144, 145top and base of, picking, and

tracking, 140, 144salt bodies, 141, 144, 145

merged, 144, 145spatial closing and correla-

tion, 141salt-body geometry, 91salt-flood migration, and imag-

ing base of salt, 140, 141, 171, 173, 174




salt floods, 158salt overhang, 143salt sheet, 99, 100, 111, 112,

168, 169salt sutures, 144, 145

AI contrast, 144picking of, 144

salt tectonism, 170sampling frequency, seismic

data, defined, 75sampling wavenumber, 81

relative to Δx, 81relative to Nyquist wave-

length, 81relative to Nyquist wave-

number, 81seafloor, 96, 140

tracking, 140seafloor double multiple, 107seafloor scarp, 168seafloor spreading, 175search image, 3sediment flood, 98, 141, 158sediment-flood migration, 140,

171, 174and imaging base of salt,

171, 174and imaging top of salt, 140

sediment-flood–salt-flood se-quence, 143

seed points, 99, 101, 102, 103seed tracking, 151SEG positive standard display

convention, reflection seismic data, 16

seismically derived velocity, 41–56

seismic amplitudes, quantita-tive use of, and picking of reflections, 24

seismic attribute analysis, refer-ences, 22

seismic attributes, 21–34, 116amplitude, 22–28coherence, 28–30horizon time, 21inversion, 30–34two-way traveltime, 21use of, 22utility spectrum, 21

seismic data, correlation with well data, 10

seismic data, sampling, 75

seismic data quality, 3, 155, 156 (see also data qual-ity, and data manage-ment; quality, defined)

detection, 3, 155elements of, 3image fidelity, 3, 156resolution, 3, 155

seismic facies, defined, 93–94seismic facies analysis, 26, 93seismic flat spot, 19seismic event, 10seismic interpretation, subjec-

tivity of, 3seismic inversion, 30–34

and quality of data acquisi-tion and processing, 32

and synthetic sonic log, 32and time domain, 32assumptions about processing

input reflectivity data, 32correlation of, compared

with conventional reflec-tivity data, 32–33

relative to acquisition-processing-interpretation, reflection seismic data, 30

seismic migration, importance, 72–73

seismic modeling, 167appropriate complexity, 167forward modeling, 167inverse modeling, 167utility of, 167

seismic pulse, normal incidence at acoustic-impedance boundary, 9

seismic records, limitations of, 83

seismic response, 9–20and standard impedance

configuration, 15described by way of convo-

lutional model, 9measurement of, 9

seismic sequences, and uncon-formities, 92

seismic stratigraphy, 94seismic waveform and particle

motion as function of time, 11

selectivity, 3semblance plot, 45

sequence boundary, 117sequence-stratigraphic analy-

sis, 26shale, 119shear waves, 9, 173short-offset moveout correction

applied to vertical veloc-ity, 56

shot-profile one-way depth-migration method, 72

sideswipe, 66, 67signal processing, 13signal-to-noise ratio (S/N), 26,

39, 154, 155significant figures, 175, 176sine wave, and cosine wave,

phase relationship, 13single-valued workstation sys-

tems, 141single velocity function, for

vertical conversion of points, 59

sinusoidal wave, a periodic function, single fre-quency, time domain, 12

slowness, 36small offset, 51, 53smiling events, 46Snell’s law, 70“softening” of reservoirs, 166sonic logs, 36–38, 117, 118

and reflection-coefficient (RC) series, 117

and synthetic seismogram, 118interval transit time, 36rock velocities, error in,

sources, 38source-receiver offset, 43source wavelet, and wavelet

phase, 17source wavelets, and differ-

ences between composite responses, 18

spatial sample rate (Δx), 2D and 3D seismic lines, 81

speed, a scalar quantity, 35squash plot, 146, 147, 148stacked traces, 46–47, 50

and errors in moveout veloc-ities, 46–47

stacking, of data, 42, 43, 49 (see also stacking velocity)



Index 201

and optimal stacking veloc-ity, 42, 43

and volume of data, 49partial, purpose, 49

stacking velocity (Vstk), 45, 51, 54, 55, 56, 62 (see also stacking, of data; Vstk)

and Dix equation, 62and NMO velocity, 45and optimization of signal, 56and true propagation veloc-

ity, 56and root-mean-square veloc-

ity (Vrms), 45identification of, 45

stacking-velocity volume, 61standard impedance con-

figuration and seismic response, 15

statics corrections, 112strike, 88strike and dip, 115strike line, rotated into dip line,

124strike line, time-migrated, 124structural restorations, 136structures, false, in seismic

depth, interpreted as real, in true depth, 111

subsalt exploration, and mode-converted waves, 173

subsalt plays, 71subsalt section, imaging, 140subsalt targets, 3syncline, 69, 109, 110

buried focus, 69synthetic seismogram, 11, 46,

117, 118and well tie, 11, 118generated with invariant

wavelet, 11two-way time/stacking-

velocity pairs, 46synthetic sonic log, 32S-wave conversion to P-wave,

173S-waves, 9, 173

T

T (period, time-domain wave-form), 81

t (traveltime), 16

tents, 131θ (maximum dip), 79Thomsen parameters, 56

δ, and short-offset moveout correction, 56

η, and deviation of long-off-set P-wave moveout, 56

3D bin, 78, 79relation to average dip, 79relation to average veloc-

ity, 793D data compared with 2D

data, general, 1333D features on 2D displays,

rendering of, 1493D scale model, 1493D time-migrated line, 118tie point, 124–125, 148

correct, conditions for, 124–125

to a strike line, 148tilted plane-wave depth-migra-

tion method, 72tilted transverse anisotropy

(TTI), 56time-amplitude analysis, 26, 77time-depth conversion, 57–62

(see also vertical conver-sion, T to D and Z to D)

time-depth function, from check-shot survey, 59, 60

time domain, 43time-domain imaging, 171time-domain waveform, 81time-migrated dip line, 123time-migrated strike line, 124time migration, 70–71, 125,

127, 128 (see also mis-tied lines, critical factor)

and depth migration, differ-ences, 70–71

and true-dip lines, 125, 127, 128

2D, and mis-tied lines, 125, 127, 128

time migration and apparent-dip 2D migrated seismic lines, 128 (see also mis-tied lines, critical factor)

time sag, and shallow gas accu-mulations, 109

time spent and value added, correlation of, 185–187

diminishing returns, 18680-20 rule, 185gambler’s ruin, 186hidden value, 186

time structures, false, inter-preted as real depth structures, 109–112

time-to-depth conversion, and correction for velocity anisotropy, 57

titular formalities, recom-mended abandonment of, 182

Tobs (recorded traveltime, source to receiver), 38

trace spacing, 146trace stretching, 146tracking, manual versus auto-

matic, 96–104, 151 (see also automatic tracking, versus manual tracking)

errors, examples, 101–104faults, picking of, 99, 101–

104parameters for, 98–104precautionary measures, 101quality control, importance,

104seed points, 99, 101, 102, 103seed tracking, 151vertical seismic sections,

101tracking artifacts, 29“traffic-light” data-quality map,

156–157transformation of observations,

reflection-time domain into depth domain, 6

trough-over-peak amplitude response, 19, 25

and hydrocarbon-bearing reservoirs, 25

trough-over-peak reflection, misinterpreted, 113

true-dip lines, 66, 122, 125, 127, 128

and time migration, 125, 127, 128

true propagation velocity, 56true relative amplitude recovery

and preservation, 26Tstat (vertical traveltime, datum

to source depth), 38




tuning analysis, 26, 77tuning model, 76–77tuning thickness, 19, 76–77, 79

and resolution, 76turbidite reservoirs, 166Tvert (recorded traveltime, con-

verted to vertical travel-time), 38

2D data compared with 3D data, general, 133

2D imaging of subsurface, fun-damental limitation, 130

migration velocities, differ-ences between, 130

2D migration, failure of, 662D seismic lines, orthogonal

pattern aligned with predominant strike and dip, 130

tracking horizons on dip lines and strike lines, 130

2D time-migrated lines, 122, 123, 124

two-way time/stacking-velocity pairs, 46

two-way traveltime (TWT), 21, 46, 78

type line, 117type locality, of geologic for-

mation, 117

U

uncertainty, 176–178and aspects free of implica-

tion about accuracy, 176

and geologic models, 177and implication about accu-

racy, 176and risk, quantitative expres-

sion of, 177, 178and symmetry of estimate, 177common measure of, 177qualitative assessments and

quantitative expressions, 177

range of, 176relative to precision of mea-

surement, 176, 177unconformities, 85, 87, 92, 93,

94, 117and seismic sequences, 92

angular, 93utility spectrum, 21

V

V (average propagation veloc-ity), 78

validity, of measurement or calculation, 176

Vavg (average velocity), 36, 37variable amplitude response,

112variable-density display for-

mat, reflection seismic data, 15

velocity, 35–62and Dix equation, 62and sonic logs, 36and transformation from

time to depth, 35and well-velocity surveys,

36anisotropy, 35average velocity, schematic,

37, 61basic types, 61, 62error in, sources, 38interval velocity, 35, 37,

39, 61moveout, errors in, and

stacked traces, 46–47P-wave, and anisotropy, 42root-mean-square (rms)

velocity, 37, 39, 62seismically derived, 41–56sonic logs, 36–38sources of data, 36stacking, 52, 62time-depth conversion,

57–62vector quantity, and associ-

ated scalar quantity, 35velocity anisotropy, 56–57well-velocity survey, 38–41

velocity anisotropy, 42, 56–57 (see also anisotropy)

and check-shot survey, 42and time-to-depth conver-

sion, 57and vertical seismic profile,

42correction for, conditions, 57polar anisotropy, 56

velocity anomalies, and false time structures, 116

velocity picks, accuracy, as related to depth, 46

velocity pull-up, 109velocity spectrum, 46vertical conversion, T to D and

Z to D, 59–60 (see also time-depth conversion)

calibrated velocity model, 59

continuous velocity model, 59

layered velocity model, 59multiple velocity functions,

59single velocity function, 59uncertainty, estimation of,

59with layered velocity model

and interval velocities, 59, 60

with velocity functions, and time-depth functions, 59–60

vertical exaggeration, seismic display, purpose of, 146

vertical resolution, Rayleigh limit, 76

vertical seismic profile (VSP), 40, 42, 59, 117

advantages over check-shot survey, 40

and velocity anisotropy, 42and well ties, 117and well-velocity surveys,

40critical factors, 59geophones, station spac-

ing, 40walkaway VSP, 40walkover VSP, 40

vertical transverse isotropy (VTI), 56

and tilted transverse isotropy (TTI), 56

vibroseis, 38Vint (interval velocity), 35, 36,

37, 50, 53visualization, of subsurface

geology, 145–149, 182and motion of observer,

148–149



Index 203

foreshortened perspective, 146, 147, 148, 149

objectives, 146rotation of image, 146trace spacing, 146trace stretching, 146

VNMO (normal-moveout veloc-ity), 45, 50, 51, 53

accurate estimation, and ray tracing, 51

and calculation of interval velocity by Dix equa-tion, 51

relative to Vint, 50relative to Vrms, 50, 51

Vrms (root-mean-square veloc-ity), 36, 37, 51, 52

as approximation for VNMO, or stacking velocity Vstk, 51

root-mean-square velocity, 36, 37

volcanics, 19, 20VSP (see vertical seismic

profile)Vstk (stacking velocity), 45,

51 (see also stacking velocity)

W

walkaway vertical seismic profile (VSP), 40

walkover vertical seismic pro-file (VSP), 40


water injection, effect on acoustic impedance, 166

waveform, 10and frequency, amplitude,

and phase characteris-tics, 10

mathematical description for, 10

wavefront, 63, 64, 65

wavelet phase, 17, 18, 19, 20, 112–113 (see also phase)

and hydrocarbon/water con-tact, 19

and seafloor reflection, 19and source wavelet, 17critical value of, 112estimation of, 17–18, 19, 20impedance boundaries and

seismic responses, 20limitations in estimating, 20misestimated, and ampli-

tudes misinterpreted, 112–113

wavelets, 11–12, 13, 14, 15, 16, 17

and extraction from seis-mic data over windows, 11–12

and interpretation of geol-ogy, 17

causal, 16finite, band-limited, 13, 14higher-frequency compo-

nents and preferential reduction in strength, 11

noncausal, 15scaled, 16zero-phase, seismic re-

sponse, 15wavenumber, k, 81wedge model, 26, 76well data, correlation to seismic

data, importance, 183well locations, selection, 34well tie, 11, 116, 117, 118, 184

and density log, 118and synthetic seismogram,

11, 117, 118and vertical seismic profiles,

117correlation for, uncertainty,

117unsatisfactory, causes, 117

well trajectories, selection, 34

well-velocity surveys, 36, 38–41, 131

and check-shot surveys, 38, 39

and vertical seismic pro-files, 40

field setup, 38procedure, 39source and receiver geom-

etries, 40with fixed source, field

geometry, 41with moving source, field

geometry, 41wiggle traces, 15work flow and interpretation

processes, 149–151generic interpretation, 149,

151granularity in work flow,

149processes, summary of, 150

workstation systems, single-valued and multivalued, 141, 142

Z

Z-depths, and isotropic depth-migrated data, 57

compared with anisotropic depth-imaged data, 57

zero-phase wavelet, 13, 14, 15phase rotation of, 14seismic response, 15time duration for given

bandwidth, 13Zoeppritz equations, 9

and nonnormal angles of inci-dence at AI boundary, 9

Z-to-D (migrated depth-to-true vertical depth) correc-tion, 57, 111

isotropic depth-imaged data, 111



This page has been intentionally left blank


Documents

References - GeoScienceWorld