Case05 Contact normal flow permeability as a function of depth

 

The initial data file for the project is: Cont_002\Case05\Data\Cont_002_Case05.dat.  

 

The basic datafile definition is very similar to the previous cases. In this case the contact normal permeability is defined as a function of depth. Hence minimal stratigraphy data identifying top surface need to be included. Note that in this case fault angle has been increased so that the fault has depths ranging from 500m to 3500m thus facilitating demonstration of model usage.

 

For more information about contact mechanics see Overview of Contact in ParaGeo and for contact data definition see Contact Data.

 

Contact_property

Data File

 

 

* Contact_property                  NUM=1

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

 Name                           "Sand_contact"

 Compression_model                           1

 Compression_properties IDM=1

  /Normal Penalty/                       5000

 Tangential_model                            2

 Tangential_properties IDM=2

  /Tangential Penalty/                     10

  /Friction coefficient/                  0.1

 Flow_model_normal                          13

 Flow_normal_table IDM=4  JDM=3

  /Depth/            0.0      2500      2501     4000

  /Penalty Perm/     1E-20   1E-20     1E-20    1E-20

  /Filter Cake Perm/ 1E-22   1E-22     1E-31    1E-31

 Flow_model_tangential                      11

 Flow_properties_tangential IDM=1    

  /"Perm."/                 1E-22    

 Thermal_model_normal                        1

 Thermal_properties_normal IDM=2

  /Therm. Cond. (Penalty)/        12.6144E+13

  /Therm. Cond. (Filter Cake)/    12.6144E+13

 Contact_width                           0.001            

 

 

1The Flow_model_normal is set to 13 (permeability as a function of depth).

2The flow normal model requires definition of Flow_normal_table whereby the normal contact penalty and filter cake permeabilities are defined as a function of depth in a tabular form. The chosen values have been arbitrarily selected so that the deepest 1500m of the fault act as a flow barrier whereas the shallowest 2500m of the fault is highly conductive.

 

 

 

 

Stratigraphy data

Data File

 

 

* Stratigraphy_definition

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

 Top_surface_horizon       "Top"

 

 

* Stratigraphy_horizon  NUM=1

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

 Name              "Top_surface"

 Geometry_set             "Top"        

 

1Minimal stratigraphy data to identify the top surface is required in order to allow depth dependent data.

 

 

 

 

Results

 

The results for the project are in: Cont_002\Case05\Results.

 

In the results below it can be seen that the low normal conductivities of the deepest part of the fault hindered transfer of pore pressure to the hanging wall.

 

 

Cont_002_case05_01

Pore pressure contours and fault normal flow conductivity at two simulation times.  Flow velocity vectors show flow crossing the fault at the upper 2500m sections of the fault with the high normal flow conductivities.