Stratigraphy_smoothing
Contents
Data Structure: Stratigraphy_smoothing |
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Description |
Defines smoothing data for stratigraphy horizons |
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Stratigraphy_smoothing NUM=ival where ival is the data structure number |
Description |
Overview Stratigraphy_smoothing can be used to prevent roll-over of the facets defining the stratigraphy. This can occur for example in thrust zones or diapirism where sediment is locally uplifted and offset. The algorithm prevents rollover by modifying the geometry of the facets in the region of the rollover by introducing a small amount of additional sediment. This is achieved by moving the nodes that connect contiguous facets if the angle defined by those facets exceeds a defined tolerance. It should be noted that the node correction does not introduce strain in the model, but a small change in volume. If stratigraphy is defined via Stratigraphy_definition, then by default the top surface of the model will be smoothed.
Examples None
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 | Active_flag Stratigraphy smoothing active flag |
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A flag that defines whether the stratigraphy smoothing is active. Generally not required as it is set on by default. But if stratigraphy smoothing is active but no longer required it can be removed by specifying a value of - 1. Valid values are: •-1 - Deactivate and remove if defined • 0 - Not defined • 1 - Defined and active
Notes •By default stratigraphy smoothing is automatically activated if sedimentation exists with smoothing of the top surface only.
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| Smoothing_frequency Smoothing frequency |
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Defines the number of geomechanical steps between each smoothing assessment. If the problem is coupled it defines the number of increments (coupling steps) between each smoothing assessment. In coupled problems lower values of Smoothing_frequency are expected (smoothing assessment every coupling step may be desired). The default values are: •Mechanical Only Analysis: Every 10 steps •Coupled Analysis: Every coupled step
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| Surface_horizon Flag for smoothing top horizon |
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Flag to indicate whether the top surface horizon should be smoothed. Valid values are: • 0 - Do not smooth top horizon • 1 - Smooth top horizon (Default)
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| All_horizons Flag for smoothing all horizons |
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Flag to indicate whether the internal horizons of the model should be smoothed. Valid values are: • 0 - Do not smooth all horizons (Default) • 1 - Smooth all horizons
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| Angle_tolerance Angle tolerance between adjacent segments |
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Defines the angle tolerance (in degrees) between two adjacent segments for the top surface horizon smoothing (Default = 60 deg.). The angle is measured as shown in the picture below. If the angle falls below the tolerance a smoothing operation will be performed. Lower angles result in increased amounts
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| Angle_tolerance_internal Angle tolerance between adjacent segments for internal lines |
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Defines the angle tolerance (in degrees) between two adjacent segments for internal lines of the model (Default = 60 deg.). The angle is measured as shown in the picture below. If the angle falls below the tolerance a smoothing operation will be performed. Lower angles result in increased amounts of smoothing and very low angles may result in loss of features within the solution. Angle_tolerance_internal should only be specified if the tolerance for smoothing for internal lines is not equal to Angle_tolerance.
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| Displacement_factor Displacement factor for node correction |
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The smoothing operation moves the node that connects two lines a fraction of the minimum of the two line lengths. The Displacement_factor defines the fraction of the line length to calculate the node correction for the smoothing operation. The value must be in the range 0.0 to 1.0 and generally the default value of 0.5 should be used.
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| Convex_smoothing_factor Displacement factor for node correction of convex facet angles |
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By default smoothing is only applied if the adjacent facet angle is concave, which results in the smoothing algorithm reducing the facet angle by moving the node slightly away from the current location (a small gain in volume). Optionally smoothing can also be applied to convex cases; i.e. in this case the node is moved slightly into the model (a small reduction in volume). This case will more likely lead to smaller elements so should be used with caution, and generally a smaller displacement is used, via specifying Convex_smoothing_factor < 1.0, e.g. 0.25. The actual displacement factor is then the product of Displacement_factor and Convex_smoothing_factor.
Notes •It should be emphasised that the node correction does not introduce strain in the location, but a small gain/loss in volume.
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| Horizon_names List of horizon names for smoothing |
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List of horizon names that should be checked using the smoothing algorithm. This may be used for example when smoothing is desired in some of the internal lines but not all.
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| Horizon_numbers List of horizon ID numbers for smoothing |
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List of horizon ID numbers that should be checked using the smoothing algorithm. This may be used for example when smoothing is desired in some of the internal lines but not all.
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| Output_level Output level for information to the log file |
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Defines the output level of information to the log file. Valid values are: • 0 - No output data relative to stratigraphy smoothing to .res file • 1 - Limited output (Default) • 2 - Detailed output
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