OILJT
Recognised by the OPM Flow parserPROPS
OILJT activates the oil Joule-Thomson effect202 The Joule–Thomson coefficient is defined as the change in temperature with respect to an increase in pressure at constant enthalpy. in temperature calculations, and defines the oil Joule-Thomson Coefficient (“JTC”) at a given reference pressure, for when OPM Flow’s thermal option has been activated by the THERMAL keyword in the RUNSPEC.
The Joule–Thomson coefficient is defined as the change in temperature with respect to an increase in pressure at constant enthalpy.
Note
This is an OPM Flow keyword used with OPM Flow’s black-oil thermal model, that is not available in the commercial simulator’s black-oil thermal formulation.
This keyword can only be used if OPM Flow’s thermal option has been activated by the THERMAL keyword in the RUNSPEC section. Note this is different to the commercial simulator that uses the TEMP keyword in the RUNSPEC section to activate the black-oil thermal model, and does not include the Joule-Thomson effect in temperature calculations.
Notes:
The keyword is followed by NTPVT records as declared on the TABDIMS keyword in the RUNSPEC section.
Each data set is terminated by a “/” and there is no “/” terminator for the keyword.
The Joule–Thomson effect is when a real gas, as opposed to an ideal gas, expands, resulting in the temperature of the gas dropping203 Natural Gas Engineering (McGraw-Hill chemical engineering series), Donald L. Katz, Robert l Lee, McGraw-Hill Education, 1990 (ISBN 0071007776, 9780071007771).. For liquids the effect is the opposite, that is the internal energy is transferred to kinetic energy with a corresponding increase in temperature as velocity increases.
Natural Gas Engineering (McGraw-Hill chemical engineering series), Donald L. Katz, Robert l Lee, McGraw-Hill Education, 1990 (ISBN 0071007776, 9780071007771).
Thermodynamically, the Joule–Thomson coefficient is defined as the isenthalpic204 An isenthalpic process or isoenthalpic process, is a process that proceeds without any change in enthalpy, H; or specific enthalpy, h. change in temperature in a fluid caused by a unitary pressure drop, as shown in the following equation:
An isenthalpic process or isoenthalpic process, is a process that proceeds without any change in enthalpy, H; or specific enthalpy, h.
[%eta` `=`` left({ partial T} over {partial P} right)]
(8.66)
Which can also express as205 Pippard, A.B.: Elements of Classical Thermodynamics: For Advanced Students of Physics. Cambridge University Press, Cambridge, UK (1957):
Pippard, A.B.: Elements of Classical Thermodynamics: For Advanced Students of Physics. Cambridge University Press, Cambridge, UK (1957)
[%eta ``=`` left( T %alpha``-``1 right) 1 over( %rho C_p )``-`` left( g over C_p dp over dz right)^-1]
(8.67)
Setting the gravity term, [g], to zero we have:, to zero we have:
[%eta ``=`` left( T %alpha``-``1 right) 1 over( %rho C_b )]
(8.68)
Where:
[%eta]=Joule–Thomson coefficient °C/Pa),
[%alpha]=thermal expansivity at constant pressure (1/°C),
[C_p]= specific heat at constant pressure (J/kg °C),
[g]= gravitational acceleration (m/s2)
[P]= pressure (Pa),
[T]= temperature °C), and
[z]= height (m).
- Records
- Fixed number of records
- Items per record
- 2
Parameters
| No. | Name | Description | Type | Dimension | Field | Metric | Lab | Default |
|---|---|---|---|---|---|---|---|---|
| 1 | PREFmanual: PRESS | A real positive value that defines the reference pressure for the corresponding Joule-Thomson Coefficient, OILJTC. | DOUBLE | Pressure | psia | barsa | atma | None |
| 2 | JOULE_manual: OILJTC | OILJTC is a real positive or negative value that defines the oil phase Joule-Thomson Coefficient. If the value is defaulted (1*) or set to 0, then OILJTC is internally calculated using the thermal oil density data on the OILDENT keyword in the PROPS section. If a non-zero value is specified, then the OILJTC is assumed to be constant and equal to that value. | DOUBLE | AbsoluteTemperature/ | °F/ | °C/ | °C/ | 0 |
Example
The following example shows the OILJT keyword for when the thermal option has been activated by the THERMAL keyword in the RUNSPEC section, and for when NTPVT on the TABDIMS keyword in the RUNSPEC section is set equal to two.
--
-- OIL JOULE-THOMSON COEFFICIENT (OPM FLOW EXTENSION KEYWORD)
--
-- REF OIL
-- PRESS JTC
-- -------- -------
OILJT
20.0 1* / TABLE NO. 01
20.0 -0.20 / TABLE NO. 02
Here the first entry is defaulted, and the simulator will therefore calculate the oil JTC internally using the data on the OILDENT keyword in the PROPS section.
There is no terminating “/” for this keyword.
| Note This is an OPM Flow keyword used with OPM Flow’s black-oil thermal model, that is not available in the commercial simulator’s black-oil thermal formulation. |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [%eta` `=`` left({ partial T} over {partial P} right)] | (8.66) |
|--------------------------------------------------------|--------|
| [%eta ``=`` left( T %alpha``-``1 right) 1 over( %rho C_p )``-`` left( g over C_p dp over dz right)^-1] | (8.67) |
|--------------------------------------------------------------------------------------------------------|--------|
| [%eta ``=`` left( T %alpha``-``1 right) 1 over( %rho C_b )] | (8.68) |
|-------------------------------------------------------------|--------|Manual source: parts/chapters/subsections/8.3/OILJT.fodt