Rest_003_Rest Restoration model
Contents
For the restoration model the initial geometry considers only the sediments to be restored (salt is removed). In the figure below the geometry and boundary conditions is shown. The sediment horizon ages is indicated. The porosity trend to initialize the simulation and to perform the decompaction is shown below.
Look for ! TODO text in the datafile and follow the instructions.
Restoration model geometry and boundary conditions (left). Porosity trend to initialize the model and perform vertical decompaction (right).
Basic Set Up: Data File Description
The initial data file for the project is: Rest_003\01 Restoration\Data\Rest_003_Rest.dat. Look for ! TODO text in the datafile and follow the instructions. The basic data includes:
1Geometry_data to read the .geo file containing the geometry 2Group data for the three formations which are assigned the "Elastic_dec" properties using Group_control_data and Group_data data structures. 3Geometry_set data defining two model boundaries 4Stratigraphy_definition and Stratigraphy_horizon identifying the three formations top horizons. 5A Material_data and Fluid_properties data structures defining elastic material properties with vertical decompaction. 6Geostatic_data, Spatial_variation_definition and Spatial_variation_values to define the initial porosity trend vs depth to initialise the model. Note that this Spatial_variation_definition is also assigned in Material_data in order to perform the vertical decompaction. 7A second set of Geostatic_data, Spatial_variation_definition and Spatial_variation_values that will be included in the exported isopachs to perform pre-compacted sedimentation during the forward simulation. 8Support data (Support_data) defining fixity in X direction at the pin line location (West_fix). 9Mesh control (Mesh_control) and Unstructured mesh generation data (Unstructured_mesh_data) defining an element size between 50 m and 100 m. 10Restoration_data defining: (a) Assignment of restoration surface (b) The restoration operation (i.e. Translate for first stage and Restore for subsequent stages) (c) Decompaction type (set to None for first stage and continuous for subsequent stages) (d) The time curve for the decompaction (e) Data related to the isopach output 11Part geometry data (Part_geometry_set, Part_line and Part_nodal_data) to define the restoration surface 12Time scaling data (Time_scaling_data) with optimal time step 1E-5 Ma. 13Damping data (Damping_global_data) to define bulk damping on the effective mean stress (Bulk Viscosity model) 14Control data (Control_data) for three stages defining: (a) Incremental solution algorithm (Type 1), (b) Maximum number of time steps of 108 (very large to avoid premature termination) (c) Durations of 1 Ma, 1 Ma and 1.5 Ma for the three stages. (d) Factor of critical time step = 0.5, (e) Plot file output every 0.2 Ma, (f) Plot file output at the end of the stage, (g) Screen message output every 1000 mech steps, (h) Output of a restart file at the end of the stage.
The aim of the present tutorial example is to demonstrate the restoration to forward simulation work flow for mini-basins type models. Thus the user is assumed to have undertaken other tutorial examples previously and be familiar with most basic data structures so only the most relevant data structures or data set up for the present case will be described in detail.
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Results
The result files for the project are in directory: Rest_003\01 Restoration\Results.
In the figures below it can be seen the geometry configuration at the end of each restoration step and the matching output isopachs. In the output .dat files containing data for sedimentation of the isopachs and corresponding control data it can be seen that
1.A Sedimentation_horizon data structure is generated for each isopach. 2.The generated Sedimentation_data contains information about the material, material file and geostatic set assigned for the isopach to be deposited 3.The duration of each stage is consistent with the restoration step of the corresponding formation. 4.The Initial_time_increment is defined according to the duration of the stage and the defined Isopach_flow_steps
Geometry configuration at the end of each restoration step
Output isopachs
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