Attributes Table

Attributes

Information

Energy

• Description: sum of Amplitudes Squared in a time-gate
• Plugin: OS, OD
• Stratigraphic: highlights packages with different reflection strengths
• Siliciclastics: energy may correlate with lithology & porosity
• Fluids: enhances Bright Spots
• Other: use Sqrt output option to control output dynamic range
• References

Scaling

• Description: various functions to correct amplitudes vs. time
• Plugin: OS, OD
• Structural: scaling can be tuned to facilitate structural interpretation
• Fluids: AGC time-gates smaller than 500ms should be avoided in quantitative interpretation
• Other: do not apply in workflows that require preservation of original amplitudes
• References

Event

• Description: quantifies the shape of an event or relative distance between events
• Plugin: OS, OD
• Structural: useful to determine horizon quality
• Stratigraphic: useful inputs for 3D NN facies classifications
• References

Stratal Amplitude

• Description: returns statistical property (min, max, sum etc.) of an attribute in an interval defined along one horizon or between two horizons
• Plugin: OS, OD
• Stratigraphic: useful to characterize intervals
• References

Attributes

Information

Frequency

• Description: returns a characteristic feature of an amplitude spectrum
• Plugin: OS, OD
• Stratigraphic: useful inputs for 3D NN facies classifications
• Fluids: Frequency Slope Fall may pick up frequency loss below HC reservoirs
• Other: Sweetness = RMS Energy / Average Freq. (construct with mathematics) may highlight hydrocarbons and thick sands
• References

Instantaneous

• Description: returns Instantaneous Attributes (amplitude, phase, frequency, and derivatives)
• Plugin: OS, OD
• Stratigraphic: Amp. useful for sequence boundaries and thin bed tuning; Phase for pinch-outs, sequence boundaries,lapout patterns
• Siliciclastics: Amp. correlates with lithology & porosity
• Carbonates: Freq. indicator for fractured zones which show up as low frequency anomalies
• Fluids: Freq. picks up HC associated low frequency anomalies; Amp. picks up bright spots
• References

Spectral Decomposition

• Description: decomposes a trace segment into frequency components (FFT) or Wavelet coefficients (CWT)
• Plugin: OS, OD
• Stratigraphic: picks-up thickness variations below seismic resolution caused by tuning; visualized on RGB(A) color-blended horizons; Useful inputs for 3D NN facies classifications
• Siliciclastics: useful in analysis of channel systems and turbidites using seismic geomorphology
• Fluids: hydrocarbons may have a distinctive frequency signature. Gas anomalies typically associated with low frequency components
• Noise: can be used to obtain information at high frequencies not normally believed to be useful
• Other: where there is a strong hydrocarbon signature masking the underlying geology the hydrocarbon signature may not be present at certain frequencies. These frequencies can be used to map geology
• References

Attributes

Information

Similarity

• Description: returns a value indicating how much two or more trace segments look alike
• Plugin: OS, (DS)
• Structural: visualize faults, salt edges
• Stratigraphic: visualize abrupt pinch-outs ; erosional incisions; lateral variable lithofacies
• Siliciclastics: visualize channels, point bar and barrier bar edges, can be used to identify mudflows from internal geometry
• Carbonates: visualize reef edges, karst features, fracture zones
• Other: Dip-steered Similarity is superior in dipping strata
• References

Thinned Fault Likelihood

• Description: returns the likelihood (0 and 1) of being a fault; Horizontal width is collapsed by thinning to one sample
• Plugin: FF
• Structural: visualize faults
• Carbonates: visualize fracture zones when used as input to fracture density and fracture proximity attributes
• Other: input for automated fault plane extraction and un-faulting
• References

Semblance

• Description: returns semblance coefficient which is a meassure of multichannel coherence
• Plugin: OS, OD
• Structural: visualize faults, salt edges
• Stratigraphic: visualize abrupt pinch-outs; erosional incisions; lateral variable lithofacies
• Ciliciclastics: visualize channels, point bar and barrier bar edges, can be used to identify mudflows form internal geometry
• Carbonates: visualize reef edges, karst features, fracture zones
• References

Volume Statistics

• Description: generic attribute returns a statistical property from a volume of data points
• Plugin: OS, (DS)
• Structural: core attribute in various user-defined filters, e.g. dip-steered median filter
• References

Texture

• Description: family of GLCM texture attributes from image processing to capture roughness / smoothness of the seismic response
• Plugin: OS, (DS)
• Stratigraphic: useful to capture variations in seismic facies either as stand-alone attributes, or as input to UVQ networks
• Ciliciclastics: visualize channels, lobes, slumps, flood plains etc.
• Carbonates: visualize reefs, platforms, karsts, etc.
• Other: Dip-steered Texture attributes should honor stratigraphy better than non dip-steered texture; Image anisotropy can be studied in all 13 possible directions
• References

Fracture

• Description: set of attributes to compute fracture properties
• Plugin: FF
• Structural: helps in directly visualizing fracture properties from an input fracture-related discontinuity volume, such as curvature, similarity, semblance, texture etc.
• Carbonates: characterize distance to the nearest fracture and proximity of individual fractures, as well as their density in a given area
• Fluids: proximity attribute may also be used to visualize the distance to the nearest DHI (e.g. a bright spot) defined on the basis of a simple seismic amplitude cutoff
• References

Fault Extraction

• Description: automated fault extraction work flow based on finger vein recognition algorithm (Start from Processing menu, or Volume Builder!)
• Plugin: FF
• Structural: visualize faults score volumes and fault-orientations; extract fault sticks, or fault planes
• References

Attributes

Information

Absolute Acoustic Impedance

• Description: model-driven deterministic inversion with stochastic add-on to evaluate uncertainties
• Plugin: DI, MPSI
• Stratigraphic: Impedance is a layer property, tuning-effects are removed, pinch-outs are better visible
• Siliciclastics: AI often correlates with lithology, porosity and pore-fill; Absolute impedance values are a prerequisite in quantitative rock-property predictions; input to quantitative NNs
• Carbonates: relation between AI and lithology, porosity and pore-fill is more variable and needs to be assessed on case by case basis
• Fluids: contacts may stand out better; pore-fill prediction is often possible
• Noise: inverted data contains less random noise
• Other: AI may be used for net pay estimation and assessing reservoir connectivity ; in presence of thin layers this is best done using the stochastic add-on
• References

Relative Acoustic Impedance

• Description: fast, band-limited Acoustic Impedance approach that optimally inverts data by globally honoring well information
• Plugin: SCI
• Stratigraphic: facilitates interpretation in geologic layers as opposed to interfaces
• Siliciclastics: facilitates discrimination between hard and soft layers
• Carbonates: may pick up high-porosity sweet-spots in tight carbonate reservoirs
• Fluids: highlights contacts and DHI’s
• Noise: high-frequency noise is reduced
• Other: advantage: no exact well tie needed; With SNP plugin Net Sand or Net Pay can be mapped
• References

Seismic Net Pay

• Description: computes Net Pay or Net Sand from SCI input and top and bottom reservoir horizons
• Plugin: SCI, SNP
• Siliciclastics: designed for siliciclastic settings with relatively thin reservoirs
• References

Extended Elastic Impedance

• Description: inverts angle stack data to EEI; Target EEI well logs can be created in OD from Density, P-Sonic and S-Sonic
• Plugin: DI, MPSI, SCI
• Fluids: used to incorporate pre-stack information in QI work flows for better separation of lithologies and fluids
• Noise: may help separate true and false DHI anomalies
• References

Attributes

Information

Dip

• Description: computes dips in various directions and azimuth from a SteeringCube that stores inline - and crossline dip
• Plugin: DS
• Structural: Polar dip is useful in fault interpretation; Apparent dip highlights faults in specified azimuth direction
• Stratigraphic: incisions and undulations can be emphasized calculating a lateral gradient of the dip; angular unconformeties can be visualized calculating the vertical gradient of the dip
• Other: taking gradients (convolve attribute) from the dip often enhances interpretability; apply the volume statistics - variance attribute to the dip gives a measure of chaos
• References

Curvature

• Description: group of attributes derived from a SteeringCube that return how curved the dip field is
• Plugin: DS
• Structural: highlights faults and fracture zones, local morphologies (bowl, valley, ridge, dome). In extensional settings high curvature-density is an indicator for high fracture-density. In compressional settings high fracture-density occurs in flat areas with low curvature-density
• Siliciclastics: might be used to detect differentially compacted features such as sand vs clay filled channels ; detects erosional incisions
• Carbonates: useful to pick reef edges, karst features, identification of fractured zones
• Fluids: possible usage in fluid flow patterns
• References

Attributes

Information

Mathematics

• Description: attribute that returns the output of a user-defined formula, or logical expression
• Plugin: OS, OD
• Other: used in many filters; complex chains of attributes can be computed; Supports Recursive filters (e.g. in Evaluate Attributes - default set)
• References

Dip-Steered Median Filter

• Description: edge-preserving smoothing filter; enhances laterally continuous events; removes random noise; default attribute set
• Plugin: DS
• Structural: facilitates structural interpretation, improves auto-tracker performance
• Noise: removes random noise without smearing spikes
• Other: amplitude and edge preserving
• References

Dip-Steered Diffusion Filter

• Description: sharpens faults in seismic data; Pre-processing step for fault attributes, e.g. Similarity; default attribute set
• Plugin: DS
• Structural: facilitates structural interpretation; should not be used in QI because amplitudes are shifted laterally
• Other: creates artifacts, best used as intermediate step to Fault Enhancement Filter
• References

Fault Enhancement Filter

• Description: evaluates the quality of the seismic data from Similarity; applies dip-steered median filter in good-quality data and a dip-steered diffusion filter in bad data zones (around faults); default attribute set
• Plugin: DS
• Structural: facilitates structural interpretation; sharpens the edges near discontinuities (faults), while smoothing else where; output has sharper faults and higher contrast between signal and background
• Stratigraphic: erosional incisions are also enhanced
• References

Smoothing

• Description: Structurally Oriented Filter that heavily smooths seismic without smearing across faults. Takes Thinned Fault Likelihood attribute as input
• Plugin: FF
• Structural: facilitates structural interpretation; generates seismic with razor sharp edges
• References

Seismic Spectral Blueing

• Description: attribute that balances the seismic amplitudes within the bandwidth to match the well reflectivity spectrum
• Plugin: SSB
• Structural: small scale faults get better imaged
• Noise: can create “ringing” if incorrectly applied
• Other: makes the amplitude spectrum “blue”: high frequencies have more energy that low energies
• References

Ridge Enhancement Filter

• Description: sharpens ridges in a Similarity cube; Filter compares three neighboring similarity values in four different time-slice directions and outputs the largest ridge value; improves resolution
• Plugin: OS, OD
• Structural: facilitates structural interpretation
• Other: be aware of side lobes, clip at zero
• References

Frequency Filter

• Description: lowpass, Highpass and Bandpass FFT, or Butterworth filters
• Plugin: OS, OD
• Structural: facilitates structural interpretation
• Noise: useful to remove frequency-related noise
• References

Convolve

• Description: group of filters that return the output of a convolution; Lowpass removes high frequencies and smooths the data; Laplacian is an edge-preserving filter; Prewitt returns the gradient which is used to enhance contrasts; Wavelet convolves the data with a wavelet
• Plugin: OS, OD
• Structural: facilitates structural interpretation
• Other: often used to enhance other attributes such as dip, similarity or curvature
• References

GapDecon

• Description: removes multiples from minimum-phase data with an inverse filter that aims to attenuate a user-defined part of the auto-correlation function; convert to minimum-phase: see Evaluate Attributes default set
• Plugin: OS, OD
• Structural: facilitates structural interpretation when multiples interfere with target horizons
• Stratigraphic: facilitates stratigraphic interpretation in intervals contaminated with multiples
• Other: GapDecon becomes a Whitening filter (=Spiking deconvolution) with lag=0
• References

Velocity Fan Filter

• Description: 3D filter to pass, or suppress energy with apparent velocities (Time surveys) or apparent dips (Depth surveys)
• Plugin: OS, OD
• Structural: useful e.g. to suppress flat multiples obscuring dipping primaries
• Noise: can be tuned to suppress coherent noise with specific velocity (/ dip)
• References

Match Delta & Delta Resample

• Description: two attributes that together enable residual alignment of seismic volumes; Match Delta computes vertical shifts that are applied in Delta Resample
• Plugin: OS, OD
• Structural: residual alignment of multi-azimuth stacks, or NMO sub-stack before final stacking
• Fluids: Residual alignment of Time-lapse volumes in 4D studies
• Other: Can also be used to align sub stacks prior to avo calculations
• References

Position

• Description: returns any attribute calculated at the location where another attribute has its minimum, maximum or median within a small volume
• Plugin: OS, OD
• Other: Position is the key attribute in the design of a dip-steered diffusion filter
• References

Reference Shift

• Description: moves the evaluation position in 3D space; can be used to return Amplitude at [0,0]
• Plugin: OS, OD
• Other: powerful combination with mathematics for designing special filters (e.g. ridge-enhancement)
• References

Fluid Contact Finder

• Description: stacks amplitudes along depth contour lines to enhance possible hydrocarbon effects
• Plugin: FCF
• Fluids: enhances flat-spots and amplitude anomalies; pinpoints fluid contacts; powerful tool in exploration & appraisal to investigate untested blocks
• Other: FCF pre-stack option enhances AVO effects; local FCF enhances 4D fluid-related effects
• References

Seismic Feature Enhancement

• Description: stacks traces along and across random lines to enhance flat-spots
• Plugin: SFE
• Fluids: enhances flat-spots and amplitude anomalies in channels
• References

Attributes

Information

ChimneyCube

• Description: highlights vertical disturbances in seismic data; Used in hydrocarbon migration path mapping and geohazard interpretation
• Plugin: DS, ML
• Structural: can discriminate active (vertically leaking) against passive (vertically sealing) faults
• Siliciclastics: onset of chimneys may indicate source rock
• Carbonates: highlights Thermobaric fluid paths (secondary porosity); associated A-shapes indicate porosity decrease, V-shapes indicate karstification/increase
• Fluids: gas chimney can derisk DHIs for low hydrocarbon saturation; positively identify hydrocarbon expulsion, migration and reservoir charge; predict oil vs gas phase reservoirs
• References

FaultCube

• Description: highlights major faults
• Plugin: DS, ML
• Structural: facilitates mapping of the structural framework
• Other: user can chose between two input attribute sets; standard and advanced
• References

SaltCube

• Description: highlights salt bodies
• Plugin: DS, ML
• Structural: helpful in mapping the edges of salt domes
• References

SlumpCube

• Description: highlights slumped deposits
• Plugin: DS, ML
• Stratigraphic: mapping of slumps and turbidites
• References

Fingerprint

• Description: returns how similar the seismic response is to the response at user-defined locations; response is captured by user-defined attributes
• Plugin: OS, OD
• Siliciclastics: useful to find similar good reservoirs as encountered in certain wells
• Carbonates: useful to find similar good reservoirs as encountered in certain wells
• Fluids: find similar responses as those at known oil and gas locations
• References

UVQ Waveform

• Description: clustering of seismic trace segments around a mapped horizon; available as Quick UVQ from horizon tree-menu
• Plugin: ML
• Stratigraphic: shows patterns in the interval that are associated with stratigraphy
• Siliciclastics: picks up channels, lobes, levees, bars, etc.
• Carbonates: picks up reefs, platforms, barriers, ramps, tidal flats etc.
• Other: UVQ network can also output 3D volumes; Input attributes should then be phase-independent (no waveforms)
• References

ML Classification

• Description: Supervised Neural Network Classification
• Plugin: ML
• Stratigraphic: alternative to UVQ; Difference is that patterns represent stratigraphic features the network was trained to recognize
• Siliciclastics: classification of: good vs bad reservoirs; sands/silts/shales etc.
• Carbonates: classification of: good vs bad reservoirs; reef/fore-reef/back-reef etc.
• Fluids: classification of: gas/oil/brine
• Other: target well logs can be real, or simulated with the SynthRock plugin
• References

ML Rock Property

• Description: Rock Properties predicted by MLP network that was trained on target well logs and impedance & seismic input volumes
• Plugin: ML
• Siliciclastics: AI often relates to porosity and fluids. Vshale, Gamma-ray usually requires additional pre-stack input
• Carbonates: Porosity from AI is typically feasible
• Fluids: Sw prediction may be possible with Acoustic Impedance, Elastic Impedance and Density inputs
• Other: target well logs can be real, or simulated with the SynthRock plugin
• References

Attributes

Information

Systems Tracts ID

• Description: assigns a unique ID to interpreted systems tracts for mathematical manipulations and visualization
• Plugin: HC, SSIS
• Stratigraphic: enables volume rendering of interpreted packages
• Siliciclastics: unravel depositional architecture of channel systems
• Carbonates: understand reef build-ups, platform architecture
• References

Systems Tracts Isopach

• Description: returns the thickness of the systems tract unit; helps to understand how sedimentation filled a basin as a function of geologic time
• Plugin: HC, SSIS
• Stratigraphic: used as color-overlay in Wheeler diagrams; enables study of depositional trends and sedimentation rates in space and time
• References

HorizonCube Density

• Description: returns the number of horizons in a continuous HorizonCube per time (depth) interval
• Plugin: HC
• Stratigraphic: highlights un-conformities and condensed sections
• Siciliclastics: facilitates systems tracts identification
• Carbonates: facilitates decomposition of carbonate build-ups
• References

HorizonCube Thickness

• Description: returns the thickness (in 2WT or depth) between consecutive horizons in a continuous HorizonCube
• Plugin: HC
• Stratigraphic: highlights variations in sedimentation patterns
• Siciliclastics: useful in identification of un-conformities, condensed sections, pinchouts, slumps
• Carbonates: highlights internal variations in carbonate build-ups
• References

Attributes

Information

AvO and AvA

• Description: computes Intercept & Gradient from offset or angle gathers; Derived products from I & G and near-far stacks are available as default attribute sets
• Plugin: OS, OD
• Siliciclastics: AvO/AvA analyses works best in loose, unconsolidated sands, but can be applied on more mature sands too (often AVO class I or II); can in select cases also be used for lithological prediction
• Carbonates: due to the higher and more unpredictable variations of rock properties limited success in carbonates ; review applicability on case by case basis
• Fluids: Primary DHI
• Other: well calibration and forward modeling/sensitivity analysis reduces uncertainty; note sine2 axis transformation (4.4.0c and later) needs radians as input
• References

Statistics

• Description: returns a statistical property from gathers, e.g. to create (partial) stacks that can serve as input for derived AvO attributes from default attribute set
• Plugin: OS, OD
• Structural: re-stacking with new parameters may improve structural image
• Fluids: primary use is pre-processing for AvO attributes in QI work flows
• References

Velocity Picking

• Description: pick NMO or RMO velocities on gathers as input to Pre-Stack Depth Migration
• Plugin: VMB
• Structural: structural image is improved in an iterative process of velocity picking, gridding, and seismic migration
• Other: updated velocities can be used to re-stack gathers
• References