OPM Flow Keyword Reference

CO2STORE

Recognised by the OPM Flow parserRUNSPEC

The CO2STORE keyword activates the carbon dioxide (CO2) storage model for the run to account for both carbon dioxide and water phase solubility, via the simulator’s CO2-Brine PVT model. This keyword is a compositional keyword in the commercial simulator but has been implemented in OPM Flow’s black-oil model.

The CO2-Brine PVT model computes the PVT properties such as density, viscosity, and enthalpy internally as functions of pressure, temperature, and composition by using analytic correlations and models from the literature rather than by interpolation from tabulated values. These values are transformed to the standard black-oil equivalent PVT tables internally by the simulator. A full description of the underlying PVT models is described by Sandve et al.1 Tor Harald Sandve1, Sarah E. Gasda, Atgeirr Rasmussen, and Alf Birger Rustad. Convective dissolution in field scale CO2 storage simulation using the OPM Flow simulator. Submitted to TCCS 11 – Trondheim Conference on CO2 Capture, Transport and Storage Trondheim, Norway – June 21-23, 2021.. This means that the normal PVT keywords like DENSITY, PVTO, PVDG etc. are not required by OPM Flow when this model is activated, and if entered will be ignored by the simulator. Note that the CO2-Brine PVT properties depend on the temperature and salinity and these must therefore be entered in the PROPS or SOLUTION sections. The reservoir temperature can be defined using, e.g., the RTEMP keyword. Region based salinity can be provided using the SALINITY keyword.

Tor Harald Sandve1, Sarah E. Gasda, Atgeirr Rasmussen, and Alf Birger Rustad. Convective dissolution in field scale CO2 storage simulation using the OPM Flow simulator. Submitted to TCCS 11 – Trondheim Conference on CO2 Capture, Transport and Storage Trondheim, Norway – June 21-23, 2021.

The CO2STORE keyword must be used together with either: (1) the GAS and WATER keywords (or alternatively the GASWAT keyword), or (2) the GAS and OIL keywords in the RUNSPEC section. It is recommended that the standard method option (1) is used.

The DISGASW keyword in the RUNSPEC section can be used with option (1) to model dissolution of CO2 in the Brine.

Option (1) has the advantage that it can be used with the VAPWAT and PRECSALT keywords in the RUNSPEC section to model the impact of both vaporization of residual water and salt precipitation in the near wellbore region on injectivity of CO2 injection wells.

In option (1), the GAS and WATER (or GASWAT) keywords declare that the gas and water phases are present in the model. When the CO2STORE option is used the water phase represents the brine and the gas phase represents CO2. Note that the input and output keywords need to be consistent with this assumption, e.g., GSF (gas saturation function) and WSF (water saturation function) should be used for the CO2-Brine relative permeability, etc.

Although, the DISGAS and VAPOIL keywords can be used with option (2) to model CO2 dissolution and water vaporization, salt precipitation is not supported with option (2).

In option (2), the GAS and OIL keywords declare that the gas and oil phases are present in the model. Internally when CO2STORE is used the oil phase refers to the brine and the gas phase to CO2. Again, the input and output keywords need to be consistent with this assumption, e.g., SGOF (gas-oil relative permeability) is used for the CO2-Brine relative permeability, FOIP (Field Oil-In-Place) shows the total amount of brine in the reservoir, etc.

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 example shows the standard usage of CO2STORE with Option (1) the Gas-Water model (GASWAT). Here we also activate the dissolved gas in water (DISGASW) and vaporized water in gas (VAPWAT) options in the RUNSPEC section.
-- ==============================================================================
--
-- RUNSPEC SECTION
--
-- ==============================================================================
RUNSPEC
-- ------------------------------------------------------------------------------
-- FLUID TYPES AND TRACER OPTIONS
-- ------------------------------------------------------------------------------
--
-- ACTIVATE CO2 STORAGE IN THE MODEL (OPM FLOW CO2 STORAGE KEYWORD)
--
CO2STORE
--
-- ACTIVATE GAS-WATER THE MODEL (OPM FLOW KEYWORD)
--
GASWAT
--
-- DISSOLVED GAS IN WATER IS PRESENT IN THE RUN (OPM FLOW KEYWORD)
--
DISGASW
--
-- VAPORIZED WATER IN DRY/WET GAS IS PRESENT IN THE RUN (OPM FLOW KEYWORD)
--
VAPWAT
The second part of the example covers the data required for the PROPS section, in which the two-phase relative permeability functions are set using GSF and WSF keywords.
-- ==============================================================================
--
-- PROPS SECTION
--
-- ==============================================================================
PROPS
--
-- RESERVOIR
-- TEMPERATURE
-- -----------
RTEMP
80.0 / RESERVOIR TEMP
--
-- ROCK COMPRESSIBILITY
--
-- REFERENCE PRESSURE IS TAKEN FROM THE HCPV WEIGHTED RESERVOIR PRESSURE
--
-- REF PRES CF
-- BARSA 1/BARSA
-- -------- --------
ROCK
200.0 5.0E-05 / ROCK COMPRESSIBILITY
--
-- GAS RELATIVE PERMEABILITY TABLES (OPM FLOW KEYWORD)
--
GSF
-- SGAS KRG PCGW
-- FRAC PSIA
-- -------- -------- -------
0.000 0.000 0.0
0.080 0.001 0.0
0.170 0.010 0.0
0.350 0.050 0.0
0.530 0.200 0.0
0.620 0.350 0.0
0.650 0.390 0.0
0.710 0.560 0.0
0.800 1.000 0.0 / TABLE NO. 01
--
-- WATER RELATIVE PERMEABILITY TABLES (OPM FLOW KEYWORD)
--
WSF
-- SWAT KRW
-- FRAC
-- -------- --------
0.200 0.0000
0.400 0.1000
0.800 0.5000
1.000 1.0000 / TABLE NO. 01
--
-- SET SALINITY FOR ALL CELLS (OPM FLOW KEYWORD)
--
SALINITY
0.7 /
No other data is required to define the fluid and rock properties in the PROPS section as the data is generated from internal analytic correlations and models by the simulator. Finally, note that units for salinity are to the 10-3, thus for metric units we have 10-3 x kg-M/kg.
The third part of the example covers initializing the model in the SOLUTION section. Here we set the EQUIL(EQLOPT6) parameter equal to one, to use table number one of the RVWVD keyword, in order to set the vaporized water versus depth distribution for the model.
-- ==============================================================================
--
-- SOLUTION SECTION
--
-- ==============================================================================
SOLUTION
--
-- SYSTEM IS SATURATED WITH WATER
--
-- DATUM DATUM OWC PCOW GOC PCGO RS RV N E300 RVW
-- DEPTH PRESS DEPTH ---- DEPTH ---- OPT OPT OPT OPT OPT
EQUIL
2000.0 200.0 1800.0 0.00 1800.0 0.00 1* 1* 1* 2* 1 /
--
-- WATER VAPOR RATIO VS DEPTH (OPM FLOW KEYWORD)
--
-- DEPTH RVW
-- STB/MSCF
-- ------ --------
RVWVD
1000.0 0.000
3000.0 0.000 / RVW VS DEPTH EQUIL REGN 01
In the SUMMARY section, the simulator supports summary vectors specific to CO2 storage (see Section 11.1.12 Option Specific Variables - CO2STORE/H2STORE Model) including those shown below.
-- ==============================================================================
--
-- SUMMARY SECTION
--
-- ==============================================================================
SUMMARY
--
-- EXPORT STANDARD SUMMARY VARIABLE VECTORS TO FILE
--
ALL
--
-- FIELD CO2 DISOLVED IN WATER PHASE
FWCD
--
-- FIELD CO2 TRAPPED IN GAS PHASE
FGCDI
--
-- FIELD CO2 MOBILE IN GAS PHASE
FGCDM
The final part of the example covers the SCHEDULE section. The standard WCONINJE keyword is used to set the gas injection rate, in this case 100,000 sm3/day of CO2.
-- ==============================================================================
--
-- SCHEDULE SECTION
--
-- ==============================================================================
SCHEDULE
--
-- RESTART CONTROL BASIC (LAST=1, ALL=2, YEARLY=4, MONTHLY=5, TSTEP=6)
--
RPTRST
'BASIC=2' ALLPROPS TEMP RSWSAT RVWSAT /
--
-- WELL SPECIFICATION DATA
--
-- WELL GROUP LOCATION BHP PHASE DRAIN INFLOW OPEN CROSS PVT
-- NAME NAME I J DEPTH FLUID AREA EQUANS SHUT FLOW TABLE
WELSPECS
INJ1 'G1' 25 25 1* GAS /
/
--
-- WELL CONNECTION DATA
--
-- WELL --- LOCATION --- OPEN SAT CONN WELL KH SKIN D DIR
-- NAME II JJ K1 K2 SHUT TAB FACT DIA FACT FACT FACT PEN
COMPDAT
INJ1 25 25 1 10 OPEN 1* 1* 0.3 /
/
--
-- WELL INJECTION CONTROLS
--
-- WELL FLUID OPEN/ CNTL SURF RESV BHP THP VFP
-- NAME TYPE SHUT MODE RATE RATE PRES PRES TABLE
WCONINJE
INJ1 GAS OPEN RATE 100000 1* 300 /
/
--
-- ADVANCE SIMULATION BY REPORTING TIME
--
TSTEP
36*30.4375
/
Note in order to get the liquid phase mole fractions of CO2, that is, the mole fractions of CO2 in the water phase (XMFCO2), and the vapor phase mole fractions (YMFWAT) to the restart file, one must use the command line parameter enable-opm-rst-file set equal to true.
The second example shows how to use CO2STORE with the alternative option (2). The example below declares that the carbon dioxide storage model is active for the run to account for both carbon dioxide and water phase solubility using OPM Flow’s CO2-Brine PVT model. Option (2) is used where the OIL phase refers to the brine and the GAS phase to CO2.
-- ==============================================================================
--
-- RUNSPEC SECTION
--
-- ==============================================================================
RUNSPEC
-- ------------------------------------------------------------------------------ -- FLUID TYPES AND TRACER OPTIONS
-- ------------------------------------------------------------------------------ --
-- ACTIVATE CO2 STORAGE IN THE MODEL (OPM FLOW CO2 STORAGE KEYWORD)
--
CO2STORE
--
-- OIL PHASE IS PRESENT IN THE RUN BUT IS THE BRINE PHASE FOR CO2STORE
--
OIL
--
-- GAS PHASE IS PRESENT IN THE RUN BUT IS THE CO2 PHASE FOR CO2STORE
--
GAS
--
-- DISSOLVED GAS IN LIVE OIL IS PRESENT IN THE RUN (CO2 IN BRINE)
--
DISGAS
--
-- VAPORIZED OIL IN WET GAS IS PRESENT IN THE RUN (WATER IN CO2)
--
VAPOIL
The second part of the example covers the data required for the PROPS section, in which the input keywords need to be consistent with the OIL phase referring to the Brine and the GAS to CO2; that is SGOF (gas-oil relative permeability) is used to define the CO2-Brine relative permeability table.
-- ==============================================================================
--
-- PROPS SECTION
--
-- ==============================================================================
PROPS
--
-- RESERVOIR
-- TEMPERATURE
-- -----------
RTEMP
90.0 / RESERVOIR TEMPERATURE
--
-- ROCK COMPRESSIBILITY
--
-- REFERENCE PRESSURE IS TAKEN FROM THE HCPV WEIGHTED RESERVOIR PRESSURE
--
-- REF PRES CF
-- BARSA 1/BARSA
-- -------- --------
ROCK
200.0 5.0E-05 / ROCK COMPRESSIBILITY
--
-- GAS-OIL RELATIVE PERMEABILITY TABLES (SGOF) – CO2STORE PHASES
SGOF
-- SG KRG KROG PCOG
-- FRAC PSIA
-- ------- -------- ------- -------
0.00000 0.000000 1.00000 0.0000
1.00000 1.000000 0.00000 0.0000 / TABLE No. 01
--
-- SET SALINITY FOR ALL CELLS (OPM FLOW KEYWORD)
--
SALINITY
0.7 /
The third part of the example covers initializing the model in the SOLUTION section. Here we set the EQUIL(EQLOPT1 and EQLOPT2) parameters equal to one, to use table number one of the RSVD and RVVD keywords, in order to set the initial dissolved CO2 and vaporized water versus depth distribution for the model.
-- ==============================================================================
--
-- SOLUTION SECTION
--
-- ==============================================================================
SOLUTION
--
-- SYSTEM IS SATURATED WITH OIL (BRINE)
--
-- DATUM DATUM OWC PCOW GOC PCGO RS RV N E300 RVW
-- DEPTH PRESS DEPTH ---- DEPTH ---- OPT OPT OPT OPT OPT
EQUIL
2000.0 200.0 2200.0 0.00 1800.0 0.00 1 1 1* 2* 1* /
--
-- DEPTH RS
-- MSCF/STB
-- ------ --------
RSVD
1000.0 0.000
3000.0 0.000 /
--
-- DEPTH RVW
-- STB/MSCF
-- ------ --------
RVVD
1000.0 0.000
3000.0 0.000 /
See also the DRSDTCON keyword in the SCHEDULE section for details of how to control convective dissolution of carbon dioxide into the in-situ brine.

Manual source: parts/chapters/subsections/5.3/CO2STORE.fodt