Case02 Slice Model

 

The 3D slice model presented here is extracted from the basin model at the highlighted location in green outline. A full description of the geomechanical restoration and forward simulation for the slice model will not be described - only description of additional data or data different to the Case01 - Column Model is presented here.  To this end, it is recommended to familiarise with the Case01 column model before undertaking this example.

 

Simulation runs on a single 3.6GHz AMD Processor PC for Case02 slice model comprising 5965 nodes, 2899 elements took:

•Restoration - 3 minutes.

•Forward Simulation - 7 minutes.

 

Geol_002_02_01

Slice Model located at Grid cells i=34-80, j=15 in Geol_002 Basin Model with 80 x 80 grid cells (1 cell = 1km)

 

The workflow comprise four main steps:

1Step 01 - Zmap file import and output to ParaView plot file and Abaqus input .inp file.

2Step 02 - Conversion of .inp file to suitable ParaGeo geometry (.geo and .geometry) files and data .dat file.

3Step 03 - Geomechanical restoration of the defined 3D geological structure with directional strain decompaction.

4Step 04 - Forward simulation of the sedimentation process (THM modelling).

 

Each of these steps contains only a description of additional data or data different to the column example in their respective sections following.

 

Click to expand/collapseStep 01 - Zmap file import and output to ParaView plot file and Abaqus input file

 

The Zmap import data files for the slice model are in : Geol_002\Case02\01 - Zmap import\Data. The key differences in the Step 01 workflow is in the main Zmap import data file Geol_002_Case02_geom.dat.

 

Geol_002_01_01

Workflow Flowchart for Step 01 - Zmap Import

 

Data File Description

 

The main data file (Geol_002_Case02_geom.dat) for importing and processing Zmap data with the mesh discretization shown below is described with key differences to the Case01 column model.

 

Geol_002_02_02

Extraction of Slice (Sub-) Model from 'Actnum' Geol_002 Basin Model and Discretisation of Grids in i, j, k

 

 

Data File

 

 

* Util_eclipse_import

! ---------------------------------

  ........

 

 Output_file_name        "Geol_002_Case02_abaq"

 

  ........

 

 Sub_grid_dimensions  IDM=6

  /I,J,K Minimum/ 34  15  1

  /I,J,K Maximum/ 80  15  10

 

  ........

 

 Grid_subdivision_i   2

!  Grid_subdivision_j   2

 Grid_subdivision_list_k IDM=10   JDM=2

  /Layer Number/       1  2  3  4  5  6  7  8  9  10

  /No. Subdivisions/   3  3  3  3 3 3  5  3 3  3

! Horizontal_horizon_flag   1 ! Define as horizontal layers

 

  ........

 

1Util_eclipse_import data different to the Case01 column model are in bold text.  These include:

a.Output_file_name - Defines output file name to be "Geol_002_Case02_abaq".

b.Sub_grid_dimensions - Defines the minimum and maximum extent of the subgrid in i, j and k directions to extract and output.

c.Grid_subdivision_i (_j and _k) - Defines the grid sub-divisions in i, j and k directions.  Note that in the Eclipse coordinate system, k direction is top to bottom, so layer 1 corresponds to the topmost layer, i.e. formation10.

d.Horizontal_horizon_flag =1 is commented out as it is to be used only for column models.

 

 

 

Results

 

The results of the Zmap import for the slice model are in : Geol_002\Case02\01 - Zmap import\Results. The key results file include:

 

•Geol_002_Case02_abaq.inp - Abaqus input file of extracted slice model which can be readily converted to ParaGeo data in Step 02.

•Geol_002_Case02_geom_update_eclipse.xmf (and .ecl) - ParaView plot files of extracted slice model (see figure below).

 

Geol_002_02_03

Extracted Slice Model from Zmap Import (Geol_002_Case02_geom_update_eclipse.xmf, .ecl)

 

 

Click to expand/collapseStep 02 - ParaGeo Geometry Creation

 

The data files for the ParaGeo geometry creation for the slice model are in : Geol_002\Case02\02 - Geometry creation\Data. The key difference in the Step 02 workflow is in the main ParaGeo geometry creation file Geol_002_Case02_rest.inp.

 

Geol_002_01_08

Workflow Flowchart for Step 02 - ParaGeo Geometry Creation

Data File Description

 

The key difference in addition to the Case## ID is the name of the external material file containing the data for the directional strain decompaction.

 

Data File (Geol_002_Case02_rest.inp)

 

 

 ........

 

*PARAGEO CONVERSION, TYPE=GROUP, PARAGEO FILE=Geol_002_Case02_rest

 

 ........

 

*INCLUDE, INPUT=Geol_002_Case02_abaq.inp

**

*MATERIAL FILE, FILE=Geol_002_rest01a_Ss_Si_Sh_Ca.mat

 

 ........

 

 

1MATERIAL FILE defines the material data file with directional strain decompaction data to be included into the ParaGeo generated data file.

 

 

Results

 

The results of the geometry creation data for the slice model are in : Geol_002\Case02\02 - Geometry creation\Results. The key results file include:

 

•Geol_002_Case02_rest.dat - ParaGeo data file for use in geomechanical restoration Step 03.  Note that this generated data contains minimum data and the final data used in restoration will be mostly edited.

•Geol_002_Case02_rest.geo - ParaGeo "hdf" format geometry file to be included in Step 03.

•Geol_002_Case02_rest.geometry - ParaGeo geometry file with geometry, group and stratigraphy data to be included in Step 03.

 

The figure for the ParaGeo slice model hex mesh (Geol_002_Case02_rest_mesh.xmf) created from the Abaqus input file is the same as that shown in Step 01 for the extracted Zmap grid output file (Geol_002_Case02_geom_update_eclipse.xmf, .ecl).

 

 

Click to expand/collapseStep 03 - Restoration

 

Step 03 involves performing the geomechanical restoration for the slice model with directional strain decompaction as shown in the flowchart below.  This involves input of two additional files in the workflow shown in green text:

1Geol_002_rest01a_Ss_Si_Sh_Ca.mat: File containing Material_data defining the mechanical properties and directional strain decompaction.

2Geol_002_Case02_Directional_Strains.spat: File containing the directional strain spatial grid data with 3% strain in XX for the entire slice model.

 

The restoration data files for the slice model are in: Geol_002\Case02\03 - Restoration\Data.

 

Geol_002_02_05

Workflow Flowchart for Step 03 - Restoration

 

Geol_002_02_04

Initial Slice Model showing prescribed boundary conditions

 

 

Geol_002_02_06

Initial Slice Model showing locations of notional 'Well_01' and 'Well_02'

 

Basic Set Up: Data File Description

 

Key differences in the restoration data comprise:

1Geol_002_Case02_RestSurf01.dat: Part geometry data for horizontal restoration surface named "Restoration_surface" located at Z=8700m, just above the topmost Z-coordinate of the slice model, and extending slightly beyond the lateral boundaries.

2Main restoration data file Geol_002_Case02_rest.dat.

 

These differences are described in the respective sections following.

 

The restoration surface data file Geol_002_Case02_RestSurf01.dat comprise part geometry data for the restoration surface sited just above the topmost Z-coordinate of the model and extending slightly beyond the lateral boundaries.

 

Data File (Geol_002_Case02_RestSurf01.dat)

 

 

 (........)

 

* Part_nodal_data  NUM=1

! ---------------------------------

 Nodes   IDM=4

   1  2  3  4

 Coordinates  IDM=3  JDM=4

   30000 10000 8700

  83000 10000 8700

        83000 20000 8700        

   30000 20000 8700

 

1Part geometry coordinate data defined to cover the whole lateral profile of the slice model and located at Z=8700m, just above the topmost Z-coord of the initial slice model.

 

 

 

Key differences in the main restoration data file Geol_002_Case02_rest.dat comprise:

1Update all references of Case## ID.

2Include external material file Geol_002_rest01a_Ss_Si_Sh_Ca.mat containing data for directional strain decompaction for use during geostatic initialisation and translation stages.  Note that the external material file Geol_002_rest01b_Ss_Si_Sh_Ca.mat containing data for decompaction to the porosity vs depth trend will be included during the restoration 'restore' stage.

3Support data to fix the "North" and "South" boundaries in Y, fix the "East" boundary in X and couple the "West" boundary in X.

4Additional history section line data for notional 'Well_02' to output porosity at this well location for the initial model.

5Include external file Geol_002_Case02_Directional_Strains.spat containing the directional strain spatial grid data and assign to element strain variables for all groups.

6Perform directional strain decompaction with translation after geostatic initialization stage.

7Include external material file Geol_002_rest01b_Ss_Si_Sh_Ca.mat containing data for decompaction to the porosity vs depth trend during the restoration 'restore' stage and re-initialise stresses from the translation stage.

 

Following are descriptions of the key restoration data differences:

 

 

Data File

 

 

* Include   ! Material Include file with Directional Decompaction

! ----------------------------------------

 Filename Geol_002_rest01a_Ss_Si_Sh_Ca.mat

 

 

* Material_data       ! Extract from Geol_002_rest01a_Ss_Si_Sh_Ca.mat    

! ---------------------------------

 Name                                 "Mech_00_00_100_00"

! -------------------------------------------------------------

 Grain_stiffness                    70000.0   ! MPa

 Grain_density                       2700.0

! -------------------------------------------------------------

 Porosity_model_type                      1  

 Porosity                               0.7

! -------------------------------------------------------------

 Elastic_model_type                       1  

 Elastic_properties  IDM=2  

   /"Young's Modulus (E)"/          10000.0   ! MPa

   /"Poisson's Ratio (v)"/              0.3

! -------------------------------------------------------------

 Singlephase_fluid_name             "Water"

! -------------------------------------------------------------

Directional_decomp_type              2 ! Directional decompaction strain component model

Directional_decomp_properties    IDM=1 ! Magnification factor for total volume changes

  1.0

 

 (......)

 

1Material data file containing data for directional strain decompaction.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2Directional_decomp_type = 2 defines the directional strain component model.

3Directional_decomp_properties define the magnification factor for total volume changes.

 

 

Data File

 

 

* Support_data

! ----------------------------------------

 Displacement_codes IDM=3 JDM=4

  /Set 1/     1 0 0

  /Set 2/     0 1 0

  /Set 3/     0 0 1

   /Set 4/     1 1 0

 Displacement_code_geom_set IDM=3

   "East"

   "North"

   "South"

 Displacement_code_geom_ass IDM=3

    1  2  2

 

 

* Couple_freedoms      NUM=1

! ----------------------------------------

 Geomechanical_codes  IDM=3

   1 0 0

 Geometry_sets IDM=1

   "West"

 

1Support_data defining "East" boundary fixed in X, "North" and "South" fixed in Y.

 

 

 

 

 

 

 

 

 

 

2Couple_freedoms defining "West" boundary with displacements coupled in X.

 

 

 

The additional history section line data is at notional 'Well_02' location as shown in the figure above.  History section line data for 'Well_01' is as defined at the location in the column model.

 

Data File

 

 

* History_section_line      NUM=2

! ----------------------------------------

 Name                    "Well_02_las"

 Output_frequency_increment        -1 ! end of stages

 Point_distribution_type            0 ! Based on number of points

 Number_points                     10

 Section_type              "Vertical"

 Path_format                        0 ! Vertical

 Formation_data_flag                1

 Plan_coordinates  IDM=2

  33500 14500

 Output_formats  IDM=1

   "las"

 Element_data  IDM=1

   "Porosity"

 

1History_section_line data for notional 'Well_02' is defined to output (in .las format) the initial porosities of the formation layers along a vertical well path defined by the coordinates specified.

 

 

 

Include data for Directional Strain File

Data File (Geol_002_Case02_Directional_Strains.spat)

 

 

* Include

! ----------------------------------------

 Filename "Geol_002_Case02_Directional_Strains.spat"

 

 

* Spatial_grid   NUM=1 ! Extract from Geol_002_Case02_Directional_Strains.spat

! ---------------------------------

 Name              "Directional_Strains"

 Type                            "Grid3"

 Nodal_variables    IDM=6

   "Strn_xx"

   "Strn_yy"

   "Strn_zz"

   "Strn_xy"

   "Strn_yz"

   "Strn_zx"

 Num_cells_x            1

 Num_cells_y            1

 Num_cells_z            1

 Grid_coordinates   IDM=3  JDM=8

   30000.0  10000.0  0.0

         83000.0  10000.0  0.0

   30000.0  20000.0  0.0

   83000.0  20000.0  0.0

   30000.0  10000.0  10000.0

   83000.0  10000.0  10000.0

   30000.0  20000.0  10000.0

   83000.0  20000.0  10000.0

 Point_values   IDM=6  JDM=8

   -0.03          0                0                0                0                0

   -0.03          0                0                0                0                0

   -0.03          0                0                0                0                0

   -0.03          0                0                0                0                0

   -0.03          0                0                0                0                0

   -0.03          0                0                0                0                0

   -0.03          0                0                0                0                0

   -0.03          0                0                0                0                0

 

1Include spatial grid file containing directional strain data.

 

 

 

 

2Spatial grid data named "Directional_Strains" containing nodal strain variables with strains in XX of -0.03 (i.e 3% compaction).  The restoration process will decompact this strain in XX by applying a stress loading to achieve this.

 

3As the directional strain of 3% is to be applied to the whole domain, a single grid unit is used to define the eight grid coordinate data with values large enough to encompass the domain boundaries in X, Y and Z directions.

 

 

 

 

Restoration Data

•Restoration data (to perform the translation to restoration surface and directional strain decompaction) and the include file containing the part geometry data for the restoration surface data are described below.

 

Geol_002_02_07

"Restoration_surface" defined in part geometry data in Geol_002_Case02_RestSurf01.dat

 

Data File

 

 

* Include

! ---------------------------------

 Filename  "Geol_002_Case02_RestSurf01.dat"

 

 

* Restoration_data

! ---------------------------------

 Restoration_surface         "Restoration_surface"

 Operation_type                        "Translate"

 Decompaction_Type                    "Continuous"

 Spatial_grid_for_tracking                  "Disp"

 

1Include to read in the file named "Geol_002_Case02_RestSurf01.dat".  This file contains the part geometry data named "Restoration_surface" defining the planar restoration surface located at 8700m (a little above the topmost z-coordinate of formation10) and extending slightly beyond the side boundaries (as shown in picture above).

 

2Restoration_data is defined for the Operation_type "Translate" to take place in conjunction with the directional strain decompaction:

a.Decompaction_type is defined as "Continuous".

 

 

 

Include data for Material File with Porosity-Depth Trend Decompaction Spatial Data

Data File

 

 

* Include

! ------------------------------------------

 Filename  Geol_002_rest01b_Ss_Si_Sh_Ca.mat

 

1Include to read in external material file Geol_002_rest01b_Ss_Si_Sh_Ca.mat containing the four Material_data defining the mechanical properties and decompaction data to porosity vs depth trend spatial data (Spatial_variation_definition and Spatial_variation_values).

 

Note that without directional strain decompaction as in the Case01 column example, this material file is read in at the start during the geostatic initialization stage.

 

Deactivation of History Data

Data File

 

 

* History_section_line      NUM=1

! ----------------------------------------

 Active_flag      -1

 

 

* History_section_line      NUM=2

! ----------------------------------------

 Active_flag      -1

 

1History_section_line data for "Well_01" and "Well_02" defined previously in the first stage are deactivated and removed after the directional strain decompaction stage by defining Active_flag = -1.

 

 

Restoration Data

•Stress accumulated from the translation stage is re-initiazed during the ""Restore" restoration stage.

 

Data File

 

 

* Restoration_data

! ---------------------------------

 Operation_type          "Restore"

 

   .....

 

 State_reinit_flag              1

 

1Restoration_data with Operation_type "Restore" is defined with State_reinit_flag set to 1 in order to re-initialize the stresses accumulated during the previous translation stage.

 

 

 

The results of the geomechanical restoration for the slice model are in : Geol_002\Case02\03 - Restoration\Results. The key results files from the restoration step to be used in Step 04 forward simulation include:

 

•Geol_002_Case02_rest_formation01.geo - Geometry file for the pre-existing layer in the forward simulation in Step 04.

•Geol_002_Case02_rest_Disp_formation##.spat - Spatial boundary displacement data from restoration to be applied to the forward simulation in Step 04.

 

The evolution of porosity plots for the initial configuration, translation + directional strain decompaction and various restoration stages are shown below.

 

 

Geol_002_02_08

 

Evolution of porosity results at initial configuration, translation + directional strain decompaction and various restoration stages to end of restoration at t=11 Ma

 

 

Click to expand/collapseStep 04 - Forward Simulation

 

Step 04 involves performing the forward simulation for the slice model as shown in the flowchart below. The key files involved are the same as for the Case01 column model, likewise the simulation stages and process involved but with minor changes which are described in the next section.

 

The forward simulation data files for the slice model are in: Geol_002\Case02\04 - Forward simulation\Data.

 

Geol_002_01_14

Workflow Flowchart for Step 04 - Forward Simulation

 

Basic Set Up: Data File Description

 

Key differences in the forward simulation data from the column model comprise:

1Geol_002_Case02_RestSurf01.dat: Part geometry data containing the horizon at Z=8700m for deposition of formation layers. This is the same file as in Step 03 - restoration.

2Main forward simulation data file Geol_002_Case02_fwdsim.dat.  The differences in this file include:

a.Update all references of Case## ID.

b.Couple_horizon_flag (valid only for column models) is removed from Sedimentation_parameters.

c.The water level reference location is changed to the notional 'Well_02' location on the West side of the model. This is arbitrarily chosen as the reference as this side of the model has the most height difference at the end of the simulation.  A Partial_saturation_flag keyword data set to 2 is added to ensure that formations above the water table are treated as fully saturated with zero pore pressure value.

d.Num_struct_divisions in Sedimentation_data will be defined with the same number of z-divisions as in the Zmap grid data file (Geol_002_Case02_geom.dat) for the slice model.

e.Optional - Additional history section line data for 'Well_02' line path on the West side of the model to output variables such as temperature, pore pressure, hydrostatic pore pressure, porosity, stresses and Kinetic KTR at the end of every stage. The output will be in "las" format with 10 points per sedimentation layer.

f.Optional - Additional history section line data for 'Well_02' line path to output variables such as temperature, pore pressure, hydrostatic pore pressure, porosity, stresses and strains every 1.0 Ma. The output will be in "hdh" format with one point per sedimentation layer.

g.Optional - Point location for History_point data in formation02 (layer with kerogen) changed to location along 'Well_02' line path.

 

 

Sedimentation_parameters

 

Data File

 

 

* Sedimentation_parameters

! ---------------------------------

  ........

 

Couple_horizon_flag                 1

 

1Couple_horizon_flag 1 is removed as it is only to be used for column models only for stability by imposing the tops of the deposited layer to remain horizontal.

 

Sedimentation_data

 

Data File

 

 

* Sedimentation_data

! ---------------------------------

  ........

 

Num_struct_divisions        #

 

1Num_struct_divisions is defined with same number of z-divisions as in the Zmap grid data file (Geol_002_Case02_geom.dat) for the slice model, noting the opposite layer direction between the Zmap grid data (top to bottom) and the Parageo model (bottom to top).

 

 

Data File

 

 

* Water_level_data          NUM=1

! ---------------------------------

  ........

 

 Reference_location  IDM=2

  /XCoord/   33500

  /YCoord/   14500

 

  ........

 

 Partial_saturation_flag     2

 

1Reference_location X and Y-coordinates specified at 'Well_02' line path on the West side of the model. This is arbitrarily chosen to be used as reference as it has the greatest height.

2Partial_saturation_flag data set to 2 ensures that formations above the water table are treated as fully saturated with zero pore pressure value.

 

 

Two additional history section line data on the West side are defined and the history point data point location coordinate in formation02 (layer with kerogen) is changed:

•History_section_line data set 3 to represent a notional 'Well_02' line path to output variables in "las" format at the end of every stage - 10 points per sedimentation layer.

•History_section_line data set 4 to represent a notional 'Well_02' line path to output variables in "hdh" format at every 1.0 Ma - 1 point per sedimentation layer.

•History_point data point location coordinate in formation02 (layer with kerogen) is changed to be also on the West side.

 

Data File

 

 

* History_section_line      NUM=3

! ----------------------------------------

 Name                    "Well_02_las"

 Output_frequency_increment        -1 ! end of stages

 Point_distribution_type            0 ! Based on number of points for layer boundaries

 Number_points                     10

 Section_type              "Vertical"

 Path_format                        0 ! Vertical

 Formation_data_flag                1

 Plan_coordinates  IDM=2

   33500 14500

 Output_formats  IDM=1

   "las"

 Element_data  IDM=3

   "Elt_temp" "Elt_pore" "Porosity"

 Nodal_pore_pressure IDM=1

   "Pore_nod"

 Nodal_temperature IDM=1

   "Temp_nod"  

 Hydrostatic_pressure_flag         1

 Stresses  IDM=3

   "Strs_xx"  "Strs_yy"  "Strs_zz"

 Hc_kinetics_state_variables   IDM=1

   "K_KTR"

 

 

* History_section_line      NUM=4

! ----------------------------------------

 Name                    "Well_02_hdh"

 Output_frequency_time            1.0

 Point_distribution_type            0 ! Based on number of points for layer boundaries

 Number_points                      1

 Section_type               "Vertical"

 Path_format                        0 ! Vertical

 Formation_data_flag                1

 Plan_coordinates  IDM=2

   33500 14500

 Output_formats  IDM=1

   "hdh"

 Element_data  IDM=3

   "Elt_temp" "Elt_pore" "Porosity"

 Nodal_pore_pressure IDM=1

   "Pore_nod"

 Nodal_temperature IDM=1

   "Temp_nod"      

 Hydrostatic_pressure_flag         1

 Strains  IDM=6

  "Strn_xx"  "Strn_yy"  "Strn_zz"  "Strn_xy"  "Strn_yz"  "Strn_zx"

 Stresses  IDM=6

  "Strs_xx"  "Strs_yy"  "Strs_zz"  "Strs_xy"  "Strs_yz"  "Strs_zx"

 

1History_section_line data set 3 is defined to represent a notional Well_02 line path on the West side in the middle of the slice to output (in .las format) variables of the formation layers along the well path at the end of every stage:

a.Name defines the .las output file name appended with "Well_02_las".

b.Point_distribution_type set to 0 defines output at points based on Number_points.

c.Number_points in conjunction with Section_type set to "Vertical" define the number of points to output to be 10 for each group/stratigraphy unit.

d.Path_format is set to 0, i.e. vertical path.

e.Formation_data_flag set to 1 defines the output of formation data for the section line based on vertical distance.

f.Plan_coordinates defines the reference x- and y-coordinates for the section line in plan view to be located in the middle of the column.

g.Output_formats data defines the output in "las" format.

h.Element_data  defines the list of element variables such as temperature, pore pressure, hydrostatic pore pressure, porosity, stresses and kinetic KTR for output.

 

2History_section_line data set 4 is similar to data set 3 but the output will be in "hdh" format with one point per sedimentation layer and output variables every 1.0Ma.

 

 

 

History_point data for Kerogen Layer (i.e. formation02 sediment)

 

Data File

 

 

* History_point NUM=1

! ---------------------------------

  ........

 

 Point_coordinates  IDM=3  JDM=1

  33500 14500 5600

 

  ........

 

1History_point data in kerogen layer formation02 point location coordinate is changed to be on the West side in the line path of notional 'Well_02'.

 

 

 

 

The results of the forward simulation for the slice model are in : Geol_002\Case02\04 - Forward simulation\Results. Results of the high definition history files for the output variables have been processed for "Well_02" into the excel file 00_Geol_002_Case02_Results.xlsx. Some of the graphical plots are presented at the end of the results section.

 

A comparison of the target configuration and the predicted forward model configuration show very good correlation achieved in all bar the top layer (i.e last deposition layer).  This is expected due to the inconsistency in the initialization of the top layer to the NCT during forward simulation whereas in the restoration, decompaction to "Top_layer" following the NCT starts in the second restoration stage. "Continuous" decompaction can only be defined for the first restoration stage (after geostatic initialization) due to directional strain decompaction happening at the same time.

 

Geol_002_02_09

Comparison of target configuration and predicted forward model configuration (nb: plots are of material number)

 

 

The figure below shows the evolution of porosity plots in the generated forward model from initial configuration to end of deposition stage.  A comparison evolution plot of the restoration process is also presented.

 

 

Geol_002_02_10

 

Evolution of porosity in the generated forward model from initial configuration, various stages of deposition to end of forward simulation at t=120 Ma

 

 

 

Geol_002_02_08

 

Evolution of porosity in the restoration model from initial configuration, translation and various restoration stages to end of restoration at t=11 Ma

 

 

The figures below show the distribution of temperature, kinetic KTR, kinetic Vitrinite reflectance, porosity, displacements in Z, strain in ZZ, stress in ZZ, pore pressure, over-pressure and permeability in Z.  The basal thermal flux loading has resulted in increase in temperature up to 161.5°C at the base and 140°C in the kerogen formation02 layer, which is sufficient to produce a kinetic KTR percentage of 78% transformation.  Over the simulation duration of 120Ma, over-pressures up to 38MPa have developed predominantly in the bottom two shale layers with some under-pressures up to 7.5MPa focused on the East end of the model. Permeability in Z is observed to be highest in the two sandstone layers corresponding to highest porous flow expected in these layers.

 

Geol_002_02_11

 

Geol_002_02_12

Geol_002_02_13

 

Distribution of variables in generated forward model. Variables include Temperature, Kinetic KTR, Kinetic Vitrinite Reflectance, Porosity, Displacement in Z, Strain in ZZ, Stress in ZZ, Pore Pressure, Over-Pressure and Permeability in Z

 

 

The figures below show the flow vectors in the formation layers. As expected, lateral flow is greatest in the two sandstone layers (light blue) with some flow across the 80% sandstone layer (light brown) on the East boundary. All lateral flow in the bottom sandstone layer is observed to flow "upwards" along the layer towards the East end of the model which is higher, progress across the 80% sandstone layer and then flow back "downwards" along the upper sandstone layer. This transition of flow behaviour in the three layers at this East end of the model coincides with the observation of up to 7.5MB under-pressure (see picture above).

 

Geol_002_02_14

 

Flow vectors at end of forward simulation stage

 

The graphs below show plots of porosity, pore pressures and stresses along the notional 'Well_02' line on the West end of the model.  The comparison plots of porosity between the target and the generated forward model show greater deviation in the deeper layers.  As observed in the pore pressure plot, this is due to over-pressures generated which are highest in the deeper layers. The vertical and horizontal effective stresses have reduced at these lower levels to compensate for the increase in pore pressure.  The locations of the layers are highlighted with the dotted lines at their respective depths.

 

 

Geol_002_02_15

 

Porosity, Pore Pressure and Stresses at end of forward simulation stage

 

 

The graphs below show plots of kinetic KTR and temperature along the notional 'Well_02' line on the West end of the model. As expected, the kerogen formation02 layer shows hydrocarbon expulsion with kinetic KTR of 59 - 77% at temperatures of 120 - 135°C.

 

Geol_002_02_16

 

Kinetic KTR and Temperature distribution at end of forward simulation stage