PCFACT
Recognised by the OPM Flow parserPROPS
PCFACT defines the capillary pressure multiplication factor due to a change in porosity. Currently the keyword is used in conjunction with OPM Flow’s Salt Precipitation model, in which the pore space is reduced due to salt precipitating in the pore space, causing a reduction in porosity and an associated increase in capillary pressure.
Note
This is an OPM Flow specific keyword for the simulator’s Salt Precipitation model that is activated by the BRINE and PRECSALT keywords and declaring that vaporized water is present in the run via the VAPWAT keyword. All three keywords are in the RUNSPEC section.
Notes:
The keyword is followed by NTSFUN tables as declared on the TABDIMS keyword in the RUNSPEC section.
Each table must contain a minimum of two rows and a maximum of NSSFUN rows as declared on the TABDIMS keyword in the RUNSPEC section.
There must be same number of entries for each column.
Each table is terminated by a single “/” and there is no “/” terminator for the keyword.
The porosity reduction is a function of the volume fraction of salt ([s sub s]) precipitated out of the vaporized water phase, that is:) precipitated out of the vaporized water phase, that is:
[%phi ~=~ ( 1`-` s sub s) %phi sub 0]
(8.3.199.1)
The capillary pressure factor data can be estimated from the permeability and porosity factors defined by the PERMFACT keyword in the PROPS section using the Leverett J-function, for example:
[p sub c over p sub c0`=`left( {%phi over %phi sub 0} {k sub 0 over k} right) ^ {1 over 2}]
(8.3.199.2)
Where:
[%phi_0], [%phi]=the initial and scaled porosity,
[k_0], [k]=the initial and scaled permeability, and
[p_c0], [p_c]=the initial and scaled capillary pressure.
- Records
- Fixed number of records
- Variadic
- The record accepts a variable number of items
Parameters
| No. | Name | Description | Type | Dimension | Field | Metric | Lab | Default |
|---|---|---|---|---|---|---|---|---|
| 1 | DATAmanual: POROFAC | A real monotonically increasing positive columnar vector that defines the porosity factor ([%phi over %phi sub 0]) for the corresponding PCFAC vector.) for the corresponding PCFAC vector. In the simulator’s Salt Precipitation model, the maximum value of [%phi]is [%phi sub 0], implying a maximum value of one for POROFAC., implying a maximum value of one for POROFAC. | DOUBLE | 1, 1 | dimensionless | dimensionless | dimensionless | None |
| 2 | PCFAC | A real positive monotonically decreasing columnar vector that defines the capillary pressure ([p sub c]) multiplier associated with POROFAC and used to scale a grid block's capillary pressure due to the reduction in pore volume caused by salt precipitation. ) multiplier associated with POROFAC and used to scale a grid block's capillary pressure due to the reduction in pore volume caused by salt precipitation. Where: [PCFAC~=~ m left (%phi over %phi_0 right) newline with `` p sub c~=~ m left (%phi over %phi_0 right) p sub c0] | dimensionless | dimensionless | dimensionless | None |
Example
The example below defines two PCFACT tables assuming NTSFUN equals two and NSSFUN is greater than or equal to five on the TABDIMS keyword in the RUNSPEC section.
--
-- CAPILLARY PRESSURE FACTOR INCREASE DUE TO SALT PRECIPITATION
-- (OPM FLOW KEYWORD)
--
PCFACT
-- PORO PC
-- FACTOR FACTOR
-- ------- --------
0.00 2.0000
0.25 2.0000
0.50 1.4142
0.75 1.1547
1.00 1.0000 / TABLE NO. 01
-- ------- --------
0.00 2.0000
0.25 2.0000
0.50 1.4142
0.75 1.1547
1.00 1.0000 / TABLE NO. 02
Note that the capillary pressure factor has been capped for POROFAC less than 0.25.
| Note This is an OPM Flow specific keyword for the simulator’s Salt Precipitation model that is activated by the BRINE and PRECSALT keywords and declaring that vaporized water is present in the run via the VAPWAT keyword. All three keywords are in the RUNSPEC section. |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [%phi ~=~ ( 1`-` s sub s) %phi sub 0] | (8.3.199.1) |
|---------------------------------------|-------------|
| [p sub c over p sub c0`=`left( {%phi over %phi sub 0} {k sub 0 over k} right) ^ {1 over 2}] | (8.3.199.2) |
|----------------------------------------------------------------------------------------------|-------------|Manual source: parts/chapters/subsections/8.3/PCFACT.fodt