Stratigraphy_pinchout_data
Contents
Data Structure: Stratigraphy_pinchout_data |
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Description |
Stratigraphy merge/pinchout data |
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Stratigraphy_pinchout_data NUM=ival where ival is the data structure number |
Description |
Overview It should be noted that Stratigraphy_pinchout_data follows different strategies / algorithms depending on whether it is used in a 2D or 3D model.
Pinchout in 2D In some cases a given element group edge might become very thin due to pinchout. Therefore very small elements may be required in order to represent properly such pinchout of stratigraphy, thus increasing the computational cost. Furthermore numerical instabilities might arise due to mesh distortion if stratigraphy pinchout zones are deformed. Therefore a pinchout removal and geometry merge operation is an efficient tool that can help to mitigate such situations. The Stratigraphy_pinchout_data structure defines the data to control merge and pinchout checks caused by sediment geometry evolution.
Pinchout in 3D Geometry operations in 3D are more complex and may lead to undesired intersections. Thus the pinchout algorithm in 3D works by preventing further thinning of those regions of a formation which satisfy the user input criteria. To that end the stratigraphy nodes in the problematic region are moved to increase the formation thickness to a target thickness thus preventing the pinchout.
Examples demonstrating the usage of 2D pinchout include: •merge*.dat
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 | Active_flag Pinchout active flag |
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Defines whether the pinchout check is active and is only necessary if pinchout is to be deactivated. Valid values are: •-1 - Deactivate and remove pinchout data • 1 - Active pinchout data (default if defined)
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| Lower_horizon_name Name of lower horizon |
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Name of lower horizon defined by Stratigraphy_horizon considered for pinchout removal.
Notes •If no geometry is targeted for pinchout removal operation, by default the pinchout checks will consider all geometry.
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| Upper_horizon_name Name of upper horizon |
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Name of upper horizon defined by Stratigraphy_horizon considered for pinchout removal.
Notes •If no geometry is targeted for pinchout removal operation, by default the pinchout checks will consider all geometry.
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| Lower_horizon_number Lower horizon number |
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Lower horizon number defined by Stratigraphy_horizon considered for pinchout removal.
Notes •If no geometry is targeted for pinchout removal operation, by default the pinchout checks will consider all geometry.
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| Upper_horizon_number Upper horizon number |
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Upper horizon number defined by Stratigraphy_horizon considered for pinchout removal.
Notes •If no geometry is targeted for pinchout removal operation, by default the pinchout checks will consider all geometry.
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| Initiation_time Pinchout check initiation time |
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Defines the pinchout check initiation time. This may be used for example to delay the time of pinchout initiation relative to the time corresponding to the stage where pinchout data is being defined.
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| Update_frequency_time Time increment for pinchout checks |
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Defines the time increment between each pinchout check (Default 0.0 - single pinchout check).
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| Update_control_flag Flag indicating that a pinchout check should be performed at the start of each control stage |
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Description |
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Flag indicating that a pinchout check should be performed at the start of each control stage. Valid values are: • 0 - Not active • 1 - Active (perform a pinchout check at the start of each control stage).
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| Minimum_thickness Layer thickness below which merge is performed |
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Defines the layer thickness below which pinchout removal and merge is performed. Note that the length with that minimum thickness should be equal or above the length defined via Minimum_merge_length for pinchout removal to occur.
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| Absolute_minimum_thickness Layer thickness below which merge is performed irrespective of merge region length |
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Defines the layer thickness below which merge is performed irrespective of merge region length (defined via Minimum_merge_length ).
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| Mesh_size Mesh size for generation of new stratigraphy |
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Description |
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Defines the default mesh size for generation of the mesh on the newly deposited stratigraphy unit.
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| Minimum_merge_length Length tolerance for pinchout evaluation |
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Length tolerance for pinchout evaluation. The length of a geometry pinchout should be equal or larger than the Minimum_merge_length in order to trigger a pinchout removal and merge operation.
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| Angle_tolerance Angle tolerance for pinchout evaluation |
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Angle tolerance for pinchout evaluation. The maximum angle between two parallel sided lines in order to trigger a pinchout removal and merge operation.
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| Restart_output_flag Output a restart file before merge operation |
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Description |
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Flag to indicate whether a restart file before pinchout removal and merge operation should be output. Valid values are: • 0 - No output of restart file • 1 - Output of restart file
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| Target_thickness Target Layer thickness after merge is performed |
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Description |
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Defines the target layer thickness for 3D pinchout prevention.
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| Output_level Flag for indicating amount of output to the log (.res) file |
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Flag for indicating amount of output to the log (.res) file. Valid values are: •0 - minimum output (default) •1 - medium level output •2 - maximum level output
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| Side_bound_corr_flag Pinchout side boundary correction flag |
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Pinchout side boundary correction flag. Valid values are: •0 - No Correction of side boundaries during pinchout •1 - Correct side boundaries during pinchout (default)
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