PVTG
Recognised by the OPM Flow parserPROPS
PVTG defines the gas PVT properties for wet gas219 Natural gas that contains significant heavy hydrocarbons such as propane, butane and other liquid hydrocarbons is known as wet gas or rich gas. The general rule of thumb is if the gas contains less methane (typically less than 85% methane) and more ethane, and other more complex hydrocarbons, it is labeled as wet gas. Wet gas normally has GOR's less than 100,000 scf/stb or 18,000 Sm3/m3, with the condensate having a gravity greater than 50 °API.. This keyword should be used when the VAPOIL keyword has been declared in the RUNSPEC section indicating that vaporized oil (more commonly referred to as condensate) is present in the wet gas phase. The keyword may be used for gas-water and oil-water-gas input decks that contain the oil and gas phases.
Natural gas that contains significant heavy hydrocarbons such as propane, butane and other liquid hydrocarbons is known as wet gas or rich gas. The general rule of thumb is if the gas contains less methane (typically less than 85% methane) and more ethane, and other more complex hydrocarbons, it is labeled as wet gas. Wet gas normally has GOR's less than 100,000 scf/stb or 18,000 Sm3/m3, with the condensate having a gravity greater than 50 °API.
Notes:
The keyword is followed by NTPVT tables as declared on the TABDIMS keyword in the RUNSPEC section.
Each table must contain a minimum of two rows and a maximum of NPPVT rows and NRPVT Rv entries as declared on the TABDIMS keyword in the RUNSPEC section.
Apart from the PRESS data there must be same number of entries for each column.
Each sub table defining the under saturated gas properties must be terminated by “/”.
Each main table is terminated by a single “/” on a separate line and there is no “/” terminator for the keyword.
Note that provided the first table has been entered, subsequent tables may be defaulted, in this case the prior table is copied to the current table. See the second example for an illustration on how to use this feature.
Note
If the VAPWAT keyword in the RUNSPEC section is also present in the input deck, then the PVTG keyword in the PROPS section should be used to define the gas properties as function of pressure and RV, assuming water-saturated gas. Also, in this case, the PVTGW keyword, also in the PROPS section, should also be in the input deck. In this case, PVTGW defines the gas properties as function of pressure and RVW, assuming oil-saturated gas.
- Records
- One or more records, each terminated by
/ - Variadic
- The record accepts a variable number of items
Parameters
| No. | Name | Description | Type | Dimension | Field | Metric | Lab | Default |
|---|---|---|---|---|---|---|---|---|
| 1 | GAS_manual: PRESS | A real monotonically increasing down the column vector that defines the gas phase pressure, associated with the saturated condensate-gas ratio (“CGR”) or Rv, the gas formation volume factor and the gas viscosity for the corresponding pressure for the stated saturated RVS. For a given PRESS the variability of the gas formation volume factor and the gas viscosity with respect to the under-saturated Rv is optionally included as a sub table under RVU, FVFU and VISU columns, that is it is not necessary to repeat PRESS for each sub table entry. However, each sub table must be terminated by a “/”. The under saturated Rv entries are optional, except for perhaps the last PRESS entry to define the PVT properties above the initial saturation pressure. | DOUBLE | Pressure | psia | barsa | atma | None |
| 2 | DATAmanual: RVS / | A columnar vector of real positive number for both the saturated (RVS) and under saturated (RVU) Rv sub table entries. The RVS entry on the main table is the saturated CGR at the pressure indicated by PRESS and may be increasing or decreasing in value as PRESS varies. Subsequent under-saturated Rv for a sub table at the given PRESS, as defined by RVU, are monotonically decreasing for entries in a given sub table. | DOUBLE | OilDissolutionFactor, OilDissolutionFactor, Viscosity | stb/ | sm3/ | scc/ | None |
| 3 | FVFS / | A columnar vector of real decreasing down the column values that defines the corresponding gas phase formation volume factor for a given pressure (PRESS) and for a given Rv (either RVS or RVU). | rb/ | rm3/ | rcc/ | None | ||
| 4 | VISS / | VISS a columnar vector of real increasing down the column values that defines the corresponding gas phase viscosity for a given pressure (PRESS) and for a given RVS. VISU a columnar vector of real decreasing from VISS down the column values that defines the corresponding gas phase viscosity for a given pressure (PRESS) and for a given RVU. | cP | cP | cP | None |
Example
The first example defines two wet gas PVT tables assuming NTPVT equals two, NPPVT is greater than or equal to eight, and NRPVT greater than or equal to two on the TABDIMS keyword in the RUNSPEC section.
--
-- GAS PVT TABLE FOR WET GAS WITH VAPORIZED OIL
--
PVTG
-- PRES RV BG VISC
-- BARSASM^3/SM^3 RM^3/SM^3 CPOISE
-- ------ --------- ------- ------
20 0.000132 0.042340 0.01344
0 0.042310 0.01389 /
40 0.000124 0.020460 0.01420
0 0.020430 0.01450 /
60 0.000126 0.013280 0.01526
0 0.013250 0.01532 /
80 0.000135 0.009770 0.01660
0 0.009730 0.01634 /
100 0.000149 0.007730 0.01818
0 0.007690 0.01752 /
120 0.000163 0.006426 0.01994
0 0.006405 0.01883 /
140 0.000191 0.005541 0.02181
0 0.005553 0.02021 /
160 0.000225 0.004919 0.02370
0 0.004952 0.02163 /
/ TABLE NO. 1
-- PRES RV BG VISC
-- BARSASM^3/SM^3 RM^3/SM^3 CPOISE
-- ------ --------- ------- ------
20 0.000132 0.042340 0.01344 /
40 0.000124 0.020460 0.01420 /
60 0.000126 0.013280 0.01526 /
80 0.000135 0.009770 0.01660 /
100 0.000149 0.007730 0.01818 /
120 0.000163 0.006426 0.01994 /
140 0.000191 0.005541 0.02181 /
160 0.000225 0.004919 0.02370
0 0.004952 0.02163 /
/ TABLE NO. 2
The second example defines four wet gas PVT tables assuming NTPVT equals four, NPPVT is greater than or equal to eight, and NRPVT greater than or equal to two on the TABDIMS keyword in the RUNSPEC section. Here table two defaults to table one, and table four defaults to table three.
--
-- GAS PVT TABLE FOR WET GAS WITH VAPORIZED OIL
--
PVTG
-- PRES RV BG VISC
-- BARSASM^3/SM^3 RM^3/SM^3 CPOISE
-- ------ --------- ------- ------
20 0.000132 0.042340 0.01344
0 0.042310 0.01389 /
40 0.000124 0.020460 0.01420
0 0.020430 0.01450 /
60 0.000126 0.013280 0.01526
0 0.013250 0.01532 /
80 0.000135 0.009770 0.01660
0 0.009730 0.01634 /
100 0.000149 0.007730 0.01818
0 0.007690 0.01752 /
120 0.000163 0.006426 0.01994
0 0.006405 0.01883 /
140 0.000191 0.005541 0.02181
0 0.005553 0.02021 /
160 0.000225 0.004919 0.02370
0 0.004952 0.02163 /
/ TABLE NO. 1
/ TABLE NO. 2
-- PRES RV BG VISC
-- BARSASM^3/SM^3 RM^3/SM^3 CPOISE
-- ------ --------- ------- ------
20 0.000132 0.042340 0.01344 /
40 0.000124 0.020460 0.01420 /
60 0.000126 0.013280 0.01526 /
80 0.000135 0.009770 0.01660 /
100 0.000149 0.007730 0.01818 /
120 0.000163 0.006426 0.01994 /
140 0.000191 0.005541 0.02181 /
160 0.000225 0.004919 0.02370
0 0.004952 0.02163 /
/ TABLE NO. 3
/ TABLE NO. 4
Notice that in both examples there is no terminating “/” for this keyword only for a table and a sub table.
| Note If the VAPWAT keyword in the RUNSPEC section is also present in the input deck, then the PVTG keyword in the PROPS section should be used to define the gas properties as function of pressure and RV, assuming water-saturated gas. Also, in this case, the PVTGW keyword, also in the PROPS section, should also be in the input deck. In this case, PVTGW defines the gas properties as function of pressure and RVW, assuming oil-saturated gas. |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|Manual source: parts/chapters/subsections/8.3/PVTG.fodt