Attributes Table

Sum of Amplitudes Squared in a time-gate.

• Stratigraphic: Highlights packages with different reflection strengths.
• Siliciclastics: Energy may correlate with lithology and porosity.
• Fluids: Enhances Bright Spots.
• Other: Use Sqrt output option to control output dynamic range.

Various functions to correct amplitudes vs. time.

• Structural: Scaling can be tuned to facilitate structural interpretation.
• Fluids: AGC time-gates smaller than 500 ms should be avoided in quantitative interpretation.
• Other: Do not apply in workflows that require preservation of original amplitudes.

Quantifies the shape of an event or relative distance between events.

• Structural: Useful to determine horizon quality.
• Stratigraphic: Useful inputs for 3D NN facies classifications.

Returns a statistical property (min, max, sum etc.) of an attribute in an interval defined along one horizon or between two horizons.

• Stratigraphic: Useful to characterize intervals.

Returns a characteristic feature of an amplitude spectrum.

• 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 Frequency (construct with mathematics) may highlight hydrocarbons and thick sands.

Returns Instantaneous Attributes (amplitude, phase, frequency, and derivatives).

• Stratigraphic: Amplitude useful for sequence boundaries and thin bed tuning; Phase for pinch-outs, sequence boundaries, lapout patterns.
• Siliciclastics: Amplitude correlates with lithology and porosity.
• Carbonates: Frequency indicator for fractured zones which show up as low frequency anomalies.
• Fluids: Frequency picks up HC associated low frequency anomalies; Amplitude picks up bright spots.

Decomposes a trace segment into frequency components (FFT) or Wavelet coefficients (CWT).

• 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.

Returns a value indicating how much two or more trace segments look alike.

• 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.

Returns the likelihood (0 and 1) of being a fault; horizontal width is collapsed by thinning to one sample.

• 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.

Returns semblance coefficient which is a measure of multichannel coherence.

• 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.

Generic attribute returns a statistical property from a volume of data points.

• Structural: Core attribute in various user-defined filters, e.g. dip-steered median filter.

Family of GLCM texture attributes from image processing to capture roughness / smoothness of the seismic response.

• Stratigraphic: Useful to capture variations in seismic facies either as stand-alone attributes, or as input to UVQ networks.
• Siliciclastics: 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.

Set of attributes to compute fracture properties.

• 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.

Automated fault extraction workflow based on finger vein recognition algorithm (start from Processing menu, or Volume Builder).

• Structural: Visualize fault score volumes and fault-orientations; extract fault sticks or fault planes.

Model-driven deterministic inversion with stochastic add-on to evaluate uncertainties.

• 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.

Fast, band-limited Acoustic Impedance approach that optimally inverts data by globally honoring well information.

• 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 DHIs.
• Noise: High-frequency noise is reduced.
• Other: No exact well tie needed; with SNP plugin Net Sand or Net Pay can be mapped.

Computes Net Pay or Net Sand from SCI input and top and bottom reservoir horizons.

• Siliciclastics: Designed for siliciclastic settings with relatively thin reservoirs.

Inverts angle stack data to EEI; target EEI well logs can be created in OD from Density, P-Sonic and S-Sonic.

• Fluids: Used to incorporate pre-stack information in QI workflows for better separation of lithologies and fluids.
• Noise: May help separate true and false DHI anomalies.

Computes dips in various directions and azimuth from a SteeringCube that stores inline and crossline dip.

• 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 unconformities 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.

Group of attributes derived from a SteeringCube that return how curved the dip field is.

• Structural: Highlights faults and fracture zones, local morphologies (bowl, valley, ridge, dome). In extensional settings high curvature-density indicates high fracture-density; in compressional settings high fracture-density occurs in flat areas with low curvature-density.
• Siliciclastics: May 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.

Attribute that returns the output of a user-defined formula or logical expression.

• Other: Used in many filters; complex chains of attributes can be computed; supports recursive filters (e.g. in Evaluate Attributes - default set).

Edge-preserving smoothing filter; enhances laterally continuous events; removes random noise; default attribute set.

• Structural: Facilitates structural interpretation, improves auto-tracker performance.
• Noise: Removes random noise without smearing spikes.
• Other: Amplitude and edge preserving.

Sharpens faults in seismic data; pre-processing step for fault attributes, e.g. Similarity; default attribute set.

• 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.

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.

• Structural: Facilitates structural interpretation; sharpens the edges near discontinuities (faults), while smoothing elsewhere; output has sharper faults and higher contrast between signal and background.
• Stratigraphic: Erosional incisions are also enhanced.

Structurally Oriented Filter that heavily smooths seismic without smearing across faults. Takes Thinned Fault Likelihood attribute as input.

• Structural: Facilitates structural interpretation; generates seismic with razor sharp edges.

Attribute that balances the seismic amplitudes within the bandwidth to match the well reflectivity spectrum.

• 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 than low frequencies.

Sharpens ridges in a Similarity cube; compares three neighboring similarity values in four different time-slice directions and outputs the largest ridge value; improves resolution.

• Structural: Facilitates structural interpretation.
• Other: Be aware of side lobes; clip at zero.

Lowpass, Highpass and Bandpass FFT, or Butterworth filters.

• Structural: Facilitates structural interpretation.
• Noise: Useful to remove frequency-related noise.

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.

• Structural: Facilitates structural interpretation.
• Other: Often used to enhance other attributes such as dip, similarity or curvature.

Removes multiples from minimum-phase data with an inverse filter that aims to attenuate a user-defined part of the auto-correlation function.

• 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.

3D filter to pass or suppress energy with apparent velocities (Time surveys) or apparent dips (Depth surveys).

• Structural: Useful e.g. to suppress flat multiples obscuring dipping primaries.
• Noise: Can be tuned to suppress coherent noise with specific velocity (or dip).

Two attributes that together enable residual alignment of seismic volumes; Match Delta computes vertical shifts that are applied in Delta Resample.

• 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.

Returns any attribute calculated at the location where another attribute has its minimum, maximum or median within a small volume.

• Other: Position is the key attribute in the design of a dip-steered diffusion filter.

Moves the evaluation position in 3D space; can be used to return Amplitude at [0,0].

• Other: Powerful combination with mathematics for designing special filters (e.g. ridge-enhancement).

Stacks amplitudes along depth contour lines to enhance possible hydrocarbon effects.

• 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.

Stacks traces along and across random lines to enhance flat-spots.

• Fluids: Enhances flat-spots and amplitude anomalies in channels.

Highlights vertical disturbances in seismic data; used in hydrocarbon migration path mapping and geohazard interpretation.

• 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.

Highlights major faults.

• Structural: Facilitates mapping of the structural framework.
• Other: User can choose between two input attribute sets: standard and advanced.

Highlights salt bodies.

• Structural: Helpful in mapping the edges of salt domes.

Highlights slumped deposits.

• Stratigraphic: Mapping of slumps and turbidites.

Returns how similar the seismic response is to the response at user-defined locations; response is captured by user-defined attributes.

• 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.

Clustering of seismic trace segments around a mapped horizon; available as Quick UVQ from horizon tree-menu.

• 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).

Supervised Neural Network Classification.

• 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.

Rock properties predicted by an MLP network that was trained on target well logs and impedance & seismic input volumes.

• 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.

Assigns a unique ID to interpreted systems tracts for mathematical manipulations and visualization.

• Stratigraphic: Enables volume rendering of interpreted packages.
• Siliciclastics: Unravel depositional architecture of channel systems.
• Carbonates: Understand reef build-ups, platform architecture.

Returns the thickness of the systems tract unit; helps to understand how sedimentation filled a basin as a function of geologic time.

• Stratigraphic: Used as color-overlay in Wheeler diagrams; enables study of depositional trends and sedimentation rates in space and time.

Returns the number of horizons in a continuous HorizonCube per time (depth) interval.

• Stratigraphic: Highlights unconformities and condensed sections.
• Siliciclastics: Facilitates systems tracts identification.
• Carbonates: Facilitates decomposition of carbonate build-ups.

Returns the thickness (in 2WT or depth) between consecutive horizons in a continuous HorizonCube.

• Stratigraphic: Highlights variations in sedimentation patterns.
• Siliciclastics: Useful in identification of unconformities, condensed sections, pinchouts, slumps.
• Carbonates: Highlights internal variations in carbonate build-ups.

Computes Intercept & Gradient from offset or angle gathers; derived products from I & G and near-far stacks are available as default attribute sets.

• 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 a case by case basis.
• Fluids: Primary DHI.
• Other: Well calibration and forward modeling/sensitivity analysis reduces uncertainty.

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.

• Structural: Re-stacking with new parameters may improve structural image.
• Fluids: Primary use is pre-processing for AvO attributes in QI workflows.

Pick NMO or RMO velocities on gathers as input to Pre-Stack Depth Migration.

• 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.