PRECSALT
Recognised by the OPM Flow parserRUNSPEC
This keyword activates the OPM Flow Salt Precipitation model that accounts for salt precipitating out of the water phase when the water is being vaporized into the gas phase and the dissolved salt reaches the solubility limit as the pressure in the reservoir is being depleted (see the VAPWAT keyword in the RUNSPEC section). This facility is an extension to the standard Brine model, and as such the BRINE keyword in the RUNSPEC must also be present in the input deck. In general, if the PRECSALT keyword has been activated in the input deck then the VAPWAT keyword should also be activated. The keyword should only be used if both water and gas phases are active in the model.
Note
This is an OPM Flow specific keyword for the simulator’s Salt Precipitation model, note that this is an extension to the commercial simulator’s Brine model.
If the keyword is present in the input deck then the SALTSOL keyword in the PROPS section also needs to be present in the input deck to define the salt solubility. In addition, either the SALTPVD or SALTP keywords in the SOLUTION section should be used to define the initial salt precipitated saturation.
There is no data required for this keyword and there is no terminating “/” for this keyword.
- Records
- No records — the keyword stands alone
Example
The first part of the example shows the keywords for the RUNSPEC section.
-- ==============================================================================
--
-- RUNSPEC SECTION
--
-- ==============================================================================
RUNSPEC
-- ------------------------------------------------------------------------------
-- FLUID TYPES AND TRACER OPTIONS
-- ------------------------------------------------------------------------------
--
-- OIL PHASE IS PRESENT IN THE RUN
--
OIL
--
-- WATER PHASE IS PRESENT IN THE RUN
--
WATER
--
-- GAS PHASE IS PRESENT IN THE RUN
--
GAS
--
-- DISSOLVED GAS IN LIVE OIL IS PRESENT IN THE RUN
--
DISGAS
--
-- ACTIVATE STANDARD BRINE MODEL IN THE RUN
--
BRINE
--
-- ACTIVATE THE OPM FLOW SALT PRECIPITATION MODEL (OPM FLOW KEYWORD)
--
PRECSALT
The above example declares that the oil, water, gas, dissolved gas, and brine phases are present in the model, and activates the Brine (BRINE keyword) and Salt Precipitation (PRECSALT keyword) models.
The second part of the example shows the additional PVT fluid keywords require for the Salt Precipitation model in the PROPS section. Note that in addition to the Salt Precipitation model specific keywords, the standard DENSITY (or GRAVITY), PVDG, and PVTO keywords are required.
-- ==============================================================================
--
-- PROPS SECTION
--
-- ==============================================================================
PROPS
--
-- WATER SALT PVT TABLE
--
PVTWSALT
-- REF PRES REF SALT
-- PSIA LB/STB
-- -------- --------
3000.0 0.000 / REFERENCE DATA
--
-- SALTCONC BW CW VISC VISC
-- LB/STB RB/STB 1/PSIA CPOISE GRAD
-- -------- -------- ------- ------ ------
0.0 1.0 3.0E-6 1.0 1.0E-6
10.0 0.8 3.0E-6 1.0 1.0E-6 / SALT CONCENTRATION
--
-- SET SALT SOLUBILITY LIMIT FOR ALL CELLS (OPM FLOW KEYWORD)
--
SALTSOL
-- MAX SALT
-- SALTSOL DENSITY
0.500 135.46867445023383 /
In addition, to the above the PERMFACT keyword may be used to account for the reduction in porosity and permeability due to salt precipitating into the pore space. Again, in addition to the Salt Precipitation model specific keywords, the standard ROCK, SGOF, and SWOF keywords are required.
--
-- PERMEABILITY FACTOR REDUCTION DUE TO SALT (OPM FLOW KEYWORD)
--
PERMFACT
-- PORO PERM
-- FACTOR FACTOR
-- ------- --------
0.0 0.000
0.4 0.005
0.6 0.010
0.9 0.100
1.0 1.000 / TABLE NO. 01
/
In order to initialize the model in the SOLUTION section, apart from the standard equilibration keywords, the following Salt Precipitation model specific keywords should be included.
-- ==============================================================================
--
-- SOLUTION SECTION
--
-- ==============================================================================
SOLUTION
--
-- PRECIPITATED SALT VOLUME FRACTION VERSUS DEPTH (OPM FLOW KEYWORD)
--
-- DEPTH SALTPSAT
-- ------ --------
SALTPVD
8300.0 0.010
8450.0 0.010 / SALT VS DEPTH EQUIL REGN 01
--
-- DEPTH SALT-1 SALT-2 SALT-3
-- SALTCON SALTCON SALTCON
-- ------ ------- ------- -------
SALTVD
8300.0 0.500
8450.0 0.500 / SALT VS DEPTH EQUIL REGN 01
Note that OPM Flow does not support Multi-Component Brine model, thus there should only one column of salt concentrations.
Finally, in the SCHEDULE section, one may optionally one can add the injections well's injection salt concentrations, as shown below.
-- ==============================================================================
--
-- SCHEDULE SECTION
--
-- ==============================================================================
SCHEDULE
--
-- DEFINE WATER INJECTION WELL SALT CONCENTRATIONS
--
-- WELL SALT-1 SALT-2 SALT-3 SALT-4
-- NAME SALTCON SALTCON SALTCON SALTCON
-- ------- ------- ------- --------
WSALT
'INJ' 0.0000 /
/
Normally, with this option one would also include vaporized water via the VAPWAT keyword in the RUNSPEC section, as well as the PVTGW keyword to define gas PVT properties for dry gas, or the PVTGWO keyword that declares the gas PVT properties for wet gas. Both keywords are in the PROPS section. The RWGSALT keyword in the PROPS section, may be used to define the relationship of water vaporization versus pressure and salt concentration. Again, the keyword is in the PROPS section. Secondly, in the SOLUTION section, the RVW keyword can be used to set the initial equilibration vaporized water in gas ratio values for all grid cells in the model for Enumeration Initialization, or the RVWVD keyword that declares the vaporized water-gas ratio (Rvw) versus depth tables for each equilibration region, for Equilibrium Initialization.
| Note This is an OPM Flow specific keyword for the simulator’s Salt Precipitation model, note that this is an extension to the commercial simulator’s Brine model. |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|Manual source: parts/chapters/subsections/5.3/PRECSALT.fodt