MINNPCOL

Recognised by the OPM Flow parserRUNSPEC

The MINNPCOL keyword defines the minimum number of Newton iterations within a time step where the well production and injection targets may be updated, after which the well targets will be frozen until the time step calculations have converged and the time step is complete.

Note

This is an OPM Flow specific keyword that sets the minimum number of Newton iterations, as opposed to the NUPCOL keyword that defines the maximum number of Newton iterations within a time step, after which well targets are frozen.

The MINNPCOL keyword has been deprecated and the NUPCOL keyword should be used instead.

Wells under group control may suffer from some dependency with other wells in the same group that are also under group control. This may cause oscillations in the production and injection well rates within the group. In order to avoid this, the NUPCOL keyword in the RUNSPEC section can be used to set the maximum number of Newton iterations within a time step, after which the group well rates are frozen until the time step has converged. Reducing the potential for well rate oscillations within the time step may result in the group targets and limits not being exactly met in this case. Increasing the value of NUPCOL, will improve the accuracy of the group targets and limits at the expense of computational efficiency. Here, the MINNPCOL keyword sets the minimum number of Newton iterations within a timestep where the well production and injection targets may be updated.

See also section 2.2Running OPM Flow 2023-04 From The Command Lineon how to set various other numerical control parameters for OPM Flow.

Notes:

The keyword is terminated by a “/”.

Records

Fixed number of records

Record count

1

Items per record

1

Parameters

Example

--
-- DEFINE THE MIN NUMBER OF ITERATIONS TO UPDATE WELL FLOW TARGETS
--
MINNPCOL
3 /
The above example sets the MINNPCOL value to its default value of three.
| Note This is an OPM Flow specific keyword that sets the minimum number of Newton iterations, as opposed to the NUPCOL keyword that defines the maximum number of Newton iterations within a time step, after which well targets are frozen. |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

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