`TUNING`

Recognised by the OPM Flow parserSCHEDULE

The TUNING keyword defines the parameters used to control the commercial simulator’s time stepping and numerical convergence for the global grid. The keyword is similar to the TUNINGDP keyword in the SCHEDULE section that is optimized for high throughput runs. The keyword is mostly ignored by OPM Flow; however, the simulator can be instructed to read some parameters from the TUNING keyword if the appropriate command line parameter has been activated (see section 2.2Running OPM Flow 2023-04 From The Command Line).

Notes:

The keyword consists of three records, with items 1-1 to 1-11 representing record one items, 2-1 to 2-14 record two and 3-1 to 3-12 representing record number three. Each of the records are terminated by a “/” and is explicitly shown in the above rows.

There is no keyword terminating “/”.

Note that for record number two (items 2-1 to 2-13) the maximum values should always be greater than the associated target value; for example, XXXCNV should be greater than TRGCNV. Also note that the TUNING keyword is stored on the restart files (see RPTRST – Define Data to be Written to the RESTART File) enabling the parameters to be utilized in a restart run without re-specifying the keyword.

Records: Fixed number of records
Record count: 3
Items per record: record 1: 10, record 2: 13, record 3: 11

Parameters

Record 1

No.	Name	Description	Type	Dimension	Field	Metric	Lab	Default
1	`TSINIT`	TSINIT is a positive real value that defines the maximum length of the next time step. Note that whenever the keyword is used TSINIT is always set back to the default value of one, unless explicitly over written.	DOUBLE	Time	days	days	hours	1.0
2	`TSMAXZ`	TSMAXZ is a positive real value that defines the maximum length of time steps following the next time step (TSINIT).	DOUBLE	Time	days	days	hours	365.0
3	`TSMINZ`	TSMINZ is a positive real value that defines the minimum length of all time steps.	DOUBLE	Time	days	days	hours	0.1
4	`TSMCHP`	TSMCHP is a positive real value that sets the minimum time step length that can be chopped.	DOUBLE	Time	days	days	hours	0.15
5	`TSFMAX`	TSFMAX is a positive real value that specifies the maximum growth rate a time step can be increased by, subject to the maximum allowable time step size set by TSMAXZ. For example, if the current time step has converged at 10 days and TSFMAX is set to the default value, then the next time step will be 3.0 x 10 days, that is 30 days provided it is less than TSMAXZ.	DOUBLE		dimensionless	dimensionless	dimensionless	3.0
6	`TSFMIN`	TSFMIN is a positive real value that specifies the minimum decay rate a time step can be decreased by, subject to the minimum allowable time step size set by TSMINZ. For example, if the current time step has not converged at 10 days and TSFMIN is set to the default value, then the next time step will be 0.3 x 10 days, that is the maximum of 3 days and TSMINZ.	DOUBLE		dimensionless	dimensionless	dimensionless	0.3
7	`TSFCNV`	TSFCNV is a positive real value that specifies the decay rate a time step can be decreased by after a convergence failure.	DOUBLE		dimensionless	dimensionless	dimensionless	0.1
8	`TFDIFF`	TFDIFF is a positive real value that sets the time step growth factor of the time step after a convergence failure. For example, if the chopped current convergent time step is 10 days and TFDIFF is set to the default value, then the time step will be increased to 1.25 x 10 days, that is the minimum of 12.5 days and TSMAXZ.	DOUBLE		dimensionless	dimensionless	dimensionless	1.25
9	`THRUPT`	THRURT is a positive real value that specifies the maximum throughput ratio over a time step.	DOUBLE		dimensionless	dimensionless	dimensionless	1.0 x 1020
10	`TMAXWC`	TMAXWC is a positive real value that defines maximum allowed time step after a well event; for example, when a well is opened or closed, etc.	DOUBLE	Time	days	days	hours	None

Record 2

No.	Name	Description	Type	Field	Metric	Lab	Default
1	`TRGTTE`	TRGTTE is a positive real value that sets the target time truncation error.	DOUBLE	dimensionless	dimensionless	dimensionless	0.1
2	`TRGCNV`	TRGCNV is a positive real value that defines the target non-linear convergence error.	DOUBLE	dimensionless	dimensionless	dimensionless	0.001
3	`TRGMBE`	TRGMBE is a positive real value that specifies the target material balance error.	DOUBLE	dimensionless	dimensionless	dimensionless	1.0 x 10-7
4	`TRGLCV`	TRGLCV is a positive real value that specifies the target linear convergence error.	DOUBLE	dimensionless	dimensionless	dimensionless	0.0001
5	`XXXTTE`	XXXTTE is a positive real value that sets the maximum time truncation error.	DOUBLE	dimensionless	dimensionless	dimensionless	10.0
6	`XXXCNV`	XXXCNV is a positive real value that defines the maximum non-linear convergence error.	DOUBLE	dimensionless	dimensionless	dimensionless	0.01
7	`XXXMBE`	XXXMBE is a positive real value that specifies the maximum mass balance error, that is the tolerated mass balance error relative to total mass present.	DOUBLE	dimensionless	dimensionless	dimensionless	1.0 x 10-6
8	`XXXLCV`	XXXLCV is a positive real values that sets the maximum linear convergence error.	DOUBLE	dimensionless	dimensionless	dimensionless	0.0001
9	`XXXWFL`	XXXWFL is a positive real values that fixes the maximum well flow convergence error.	DOUBLE	dimensionless	dimensionless	dimensionless	0.001
10	`TRGFIP`	TRGFIP is a positive real value that stipulates the target fluid in-place error in Local Grid Refinements.	DOUBLE	dimensionless	dimensionless	dimensionless	0.025
11	`TRGSFT`	TRGSFT is a positive real values that defines the target surfactant change when the Surfactant Model is active in the run.	DOUBLE	dimensionless	dimensionless	dimensionless	None
12	`THIONX`	THIONX is a positive real value used to set the threshold for damping in the ion echange calculation for when the Brine Model is active in the run.	DOUBLE	dimensionless	dimensionless	dimensionless	0.01
13	`TRWGHT`	TRWGHT is an integer that stipulates the implicitness for active tracer updates within the Newton iterations, and should be set to: The calculation is explicit, that is fully decoupled. The calculation is implicit, that is fully coupled.	INT	dimensionless	dimensionless	dimensionless	1

Record 3

No.	Name	Description	Type	Dimension	Field	Metric	Lab	Default
1	`NEWTMX`	NEWTMX is a positive integer greater or equal to NEWTMN that stipulates the maximum number of Newton iterations for a time step.	INT		dimensionless	dimensionless	dimensionless	12
2	`NEWTMN`	NEWTMN is a positive integer that is less or equal to NEWTMX that defines the minimum number of Newton iterations for a time step.	INT		dimensionless	dimensionless	dimensionless	1
3	`LITMAX`	LITMAX is a positive integer greater or equal to LITMIN that sets the maximum number of linear iterations within a Newton iteration.	INT		dimensionless	dimensionless	dimensionless	25
4	`LITMIN`	LITMIN is a positive integer less or equal to LITMAX that sets the minimum number of linear iterations within a Newton iteration.	INT		dimensionless	dimensionless	dimensionless	1
5	`MXWSIT`	MXWSIT is a positive integer that defines the maximum number of iterations within a well flow calculation.	INT		dimensionless	dimensionless	dimensionless	8
6	`MXWPIT`	MXWPIT is a positive integer that stipulates the maximum number of iterations for solving the bottom-hole pressure for wells under tubing head pressure control within a well flow calculation.	INT		dimensionless	dimensionless	dimensionless	8
7	`DDPLIM`	DDPLIM is a positive real value that stipulates the maximum pressure change at the last Newton iteration.	DOUBLE	Pressure	psia	barsa	atma	1.0 x 106
8	`DDSLIM`	DDSLIM is a positive real value that sets the maximum saturation change at the last Newton iteration.	DOUBLE		dimensionless	dimensionless	dimensionless	1.0 x 106
9	`TRGDPR`	TRGDPR is a positive real value that defines the target maximum pressure change within a time step.	DOUBLE	Pressure	psia	barsa	atma	1.0 x 106
10	`XXXDPR`	XXXDPR is a positive real value that stipulates the maximum tolerable pressure change within a time step.	DOUBLE	Pressure	psia	barsa	atma	None
11	`MNWRFP`	MNWRFP is a positive integer greater than one and less than NEWTMX that defines the minimum number of Newton iterations before invoking the bisection algorithm for when the polymer phase is active in the model via the POLYMER keyword in the RUNSPEC section.	INT		dimensionless	dimensionless	dimensionless	4

Example

--
-- DEFAULT TUNING PARAMETERS
--
TUNING
1.0 365.0 0.1 0.15 3 0.3 0.1 1.25 1E20 1* /
/
/
The above example explicitly sets the default parameters for OPM Flow for when the appropriate command line parameter has been activated (see section 2.2Running OPM Flow 2023-04 From The Command Line) to instruct the simulator to read the first record of the TUNING keyword.Alternatively one could just use the following to accomplish the same thing.
TUNING
/
/
/

Manual source: parts/chapters/subsections/12.3/TUNING.fodt