#13281 Improve unit system handling for Eclipse files

- Add shared utility functions in RifEclipseOutputFileTools:
  - unitValueToEnum(): Convert int unit value to optional enum
  - determineUnitSystem(): Apply unit preference hierarchy and log warnings
- Implement correct unit preference hierarchy: egrid > init > unrst
  (previously was unrst > init > egrid)
- Add validation and warning when different unit systems are detected
  across files
- Enhance grid unit parsing with debug logging to explicitly document
  support for "m" as abbreviation for "METRES"

ApplicationLibCode/FileInterface/RifEclipseOutputFileTools.cpp

@@ -20,6 +20,7 @@
 
 #include "RifEclipseOutputFileTools.h"
 
+#include "RiaLogging.h"
 #include "RiaOpmParserTools.h"
 #include "RiaQDateTimeTools.h"
 #include "RiaStringEncodingTools.h"
@@ -951,3 +952,90 @@ void RifEclipseOutputFileTools::extractResultValuesBasedOnPorosityModel( RigEcli
         }
     }
 }
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+std::optional<RiaDefines::EclipseUnitSystem> RifEclipseOutputFileTools::unitValueToEnum( int unitValue )
+{
+    if ( unitValue == 1 )
+        return RiaDefines::EclipseUnitSystem::UNITS_METRIC;
+    else if ( unitValue == 2 )
+        return RiaDefines::EclipseUnitSystem::UNITS_FIELD;
+    else if ( unitValue == 3 )
+        return RiaDefines::EclipseUnitSystem::UNITS_LAB;
+
+    return std::nullopt;
+}
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+RiaDefines::EclipseUnitSystem RifEclipseOutputFileTools::determineUnitSystem( const std::optional<RiaDefines::EclipseUnitSystem>& egridUnit,
+                                                                              const std::optional<RiaDefines::EclipseUnitSystem>& initUnit,
+                                                                              const std::optional<RiaDefines::EclipseUnitSystem>& unrstUnit )
+{
+    // Helper lambda to get unit name string
+    auto getUnitName = []( RiaDefines::EclipseUnitSystem unit ) -> QString
+    {
+        if ( unit == RiaDefines::EclipseUnitSystem::UNITS_METRIC ) return "METRIC";
+        if ( unit == RiaDefines::EclipseUnitSystem::UNITS_FIELD ) return "FIELD";
+        if ( unit == RiaDefines::EclipseUnitSystem::UNITS_LAB ) return "LAB";
+        return "UNKNOWN";
+    };
+
+    // Determine which unit to use based on priority: egrid > init > unrst
+    std::optional<RiaDefines::EclipseUnitSystem> selectedUnit;
+    QString                                      selectedSource;
+
+    if ( egridUnit.has_value() )
+    {
+        selectedUnit   = egridUnit;
+        selectedSource = "EGRID";
+    }
+    else if ( initUnit.has_value() )
+    {
+        selectedUnit   = initUnit;
+        selectedSource = "INIT";
+    }
+    else if ( unrstUnit.has_value() )
+    {
+        selectedUnit   = unrstUnit;
+        selectedSource = "UNRST";
+    }
+
+    // Check for mismatches and warn
+    if ( selectedUnit.has_value() )
+    {
+        // Build list of sources that differ from selected
+        QStringList conflicts;
+
+        if ( egridUnit.has_value() && initUnit.has_value() && egridUnit.value() != initUnit.value() )
+        {
+            conflicts.append( QString( "INIT file has %1" ).arg( getUnitName( initUnit.value() ) ) );
+        }
+        if ( egridUnit.has_value() && unrstUnit.has_value() && egridUnit.value() != unrstUnit.value() )
+        {
+            conflicts.append( QString( "UNRST file has %1" ).arg( getUnitName( unrstUnit.value() ) ) );
+        }
+        if ( !egridUnit.has_value() && initUnit.has_value() && unrstUnit.has_value() && initUnit.value() != unrstUnit.value() )
+        {
+            conflicts.append( QString( "UNRST file has %1" ).arg( getUnitName( unrstUnit.value() ) ) );
+        }
+
+        if ( !conflicts.isEmpty() )
+        {
+            QString warning = QString( "Unit system mismatch detected: Using %1 from %2 file, but %3. "
+                                       "Please verify your simulation files have consistent unit systems." )
+                                  .arg( getUnitName( selectedUnit.value() ) )
+                                  .arg( selectedSource )
+                                  .arg( conflicts.join( " and " ) );
+            RiaLogging::warning( warning );
+        }
+
+        return selectedUnit.value();
+    }
+
+    // Default to METRIC if no unit found
+    return RiaDefines::EclipseUnitSystem::UNITS_METRIC;
+}

ApplicationLibCode/FileInterface/RifEclipseOutputFileTools.h

@@ -35,6 +35,7 @@
 #include <QString>
 #include <QStringList>
 
+#include <optional>
 #include <vector>
 
 using ecl_file_type = struct ecl_file_struct;
@@ -114,6 +115,12 @@ public:
                                                          std::vector<double>*          values,
                                                          const std::vector<double>&    fileValues );
 
+    // Unit system handling utilities
+    static std::optional<RiaDefines::EclipseUnitSystem> unitValueToEnum( int unitValue );
+    static RiaDefines::EclipseUnitSystem                determineUnitSystem( const std::optional<RiaDefines::EclipseUnitSystem>& egridUnit,
+                                                                             const std::optional<RiaDefines::EclipseUnitSystem>& initUnit,
+                                                                             const std::optional<RiaDefines::EclipseUnitSystem>& unrstUnit );
+
 private:
     static void                     getDayMonthYear( const ecl_kw_type* intehead_kw, int* day, int* month, int* year );
     static RifEclipseReportKeywords createReportStepsMetaData( const std::vector<ecl_file_type*>& ecl_files );

ApplicationLibCode/FileInterface/RifReaderEclipseOutput.cpp

@@ -895,34 +895,30 @@ void RifReaderEclipseOutput::buildMetaData( ecl_grid_type* grid )
 
     // Unit system
     {
-        // Default units type is METRIC
-        RiaDefines::EclipseUnitSystem unitsType = RiaDefines::EclipseUnitSystem::UNITS_METRIC;
-        int                           unitsTypeValue;
+        std::optional<RiaDefines::EclipseUnitSystem> egridUnit;
+        std::optional<RiaDefines::EclipseUnitSystem> initUnit;
+        std::optional<RiaDefines::EclipseUnitSystem> unrstUnit;
 
+        // Read from grid file
+        if ( grid )
+        {
+            egridUnit = RifEclipseOutputFileTools::unitValueToEnum( ecl_grid_get_unit_system( grid ) );
+        }
+
+        // Read from init file
+        if ( m_ecl_init_file )
+        {
+            initUnit = RifEclipseOutputFileTools::unitValueToEnum( RifEclipseOutputFileTools::readUnitsType( m_ecl_init_file ) );
+        }
+
+        // Read from restart file
         if ( m_dynamicResultsAccess.notNull() )
         {
-            unitsTypeValue = m_dynamicResultsAccess->readUnitsType();
-        }
-        else
-        {
-            if ( m_ecl_init_file )
-            {
-                unitsTypeValue = RifEclipseOutputFileTools::readUnitsType( m_ecl_init_file );
-            }
-            else
-            {
-                unitsTypeValue = ecl_grid_get_unit_system( grid );
-            }
+            unrstUnit = RifEclipseOutputFileTools::unitValueToEnum( m_dynamicResultsAccess->readUnitsType() );
         }
 
-        if ( unitsTypeValue == 2 )
-        {
-            unitsType = RiaDefines::EclipseUnitSystem::UNITS_FIELD;
-        }
-        else if ( unitsTypeValue == 3 )
-        {
-            unitsType = RiaDefines::EclipseUnitSystem::UNITS_LAB;
-        }
+        // Determine final unit system using hierarchy (egrid > init > unrst) with warnings
+        RiaDefines::EclipseUnitSystem unitsType = RifEclipseOutputFileTools::determineUnitSystem( egridUnit, initUnit, unrstUnit );
         m_eclipseCaseData->setUnitsType( unitsType );
     }
 

ApplicationLibCode/FileInterface/RifReaderOpmCommon.cpp

@@ -189,13 +189,30 @@ bool RifReaderOpmCommon::importGrid( RigMainGrid* mainGrid, RigEclipseCaseData*
     mainGrid->setDualPorosity( opmGrid.porosity_mode() > 0 );
 
     // assign grid unit, if found (1 = Metric, 2 = Field, 3 = Lab)
+    // Note: Accepts "m" or "M" as abbreviation for "METRES" (METRIC units)
     auto gridUnitStr = RiaStdStringTools::toUpper( opmGrid.grid_unit() );
     if ( gridUnitStr.starts_with( 'M' ) )
+    {
         m_gridUnit = 1;
+        RiaLogging::debug(
+            QString( "Grid unit from EGRID file: '%1' (interpreted as METRIC)" ).arg( QString::fromStdString( opmGrid.grid_unit() ) ) );
+    }
     else if ( gridUnitStr.starts_with( 'F' ) )
+    {
         m_gridUnit = 2;
+        RiaLogging::debug(
+            QString( "Grid unit from EGRID file: '%1' (interpreted as FIELD)" ).arg( QString::fromStdString( opmGrid.grid_unit() ) ) );
+    }
     else if ( gridUnitStr.starts_with( 'C' ) )
+    {
         m_gridUnit = 3;
+        RiaLogging::debug(
+            QString( "Grid unit from EGRID file: '%1' (interpreted as LAB)" ).arg( QString::fromStdString( opmGrid.grid_unit() ) ) );
+    }
+    else if ( !gridUnitStr.empty() )
+    {
+        RiaLogging::warning( QString( "Unknown grid unit from EGRID file: '%1'" ).arg( QString::fromStdString( opmGrid.grid_unit() ) ) );
+    }
 
     auto totalCellCount           = opmGrid.totalNumberOfCells();
     auto globalMatrixActiveSize   = opmGrid.activeCells();
@@ -925,12 +942,23 @@ void RifReaderOpmCommon::buildMetaData( RigEclipseCaseData* eclipseCaseData, caf
 
     // Unit system
     {
-        // Default units type is METRIC, look in restart file, then init file and then grid file until we find something
-        RiaDefines::EclipseUnitSystem unitsType      = RiaDefines::EclipseUnitSystem::UNITS_METRIC;
-        int                           unitsTypeValue = -1;
+        std::optional<RiaDefines::EclipseUnitSystem> egridUnit = RifEclipseOutputFileTools::unitValueToEnum( m_gridUnit );
+        std::optional<RiaDefines::EclipseUnitSystem> initUnit;
+        std::optional<RiaDefines::EclipseUnitSystem> unrstUnit;
 
         namespace VI = Opm::RestartIO::Helpers::VectorItems;
 
+        // Read from init file
+        if ( m_initFile != nullptr )
+        {
+            const auto& intHeader = m_initFile->getInitData<int>( "INTEHEAD" );
+            if ( intHeader.size() > 2 )
+            {
+                initUnit = RifEclipseOutputFileTools::unitValueToEnum( intHeader[2] );
+            }
+        }
+
+        // Read from restart file
         if ( m_restartFile != nullptr )
         {
             for ( auto reportStep : m_restartFile->listOfReportStepNumbers() )
@@ -940,35 +968,15 @@ void RifReaderOpmCommon::buildMetaData( RigEclipseCaseData* eclipseCaseData, caf
                     const auto& intHeader = m_restartFile->getRestartData<int>( "INTEHEAD", reportStep );
                     if ( intHeader.size() > VI::intehead::UNIT )
                     {
-                        unitsTypeValue = intHeader[VI::intehead::UNIT];
+                        unrstUnit = RifEclipseOutputFileTools::unitValueToEnum( intHeader[VI::intehead::UNIT] );
                         break;
                     }
                 }
             }
         }
 
-        if ( unitsTypeValue < 0 )
-        {
-            if ( m_initFile != nullptr )
-            {
-                const auto& intHeader = m_initFile->getInitData<int>( "INTEHEAD" );
-                if ( intHeader.size() > 2 ) unitsTypeValue = intHeader[2];
-            }
-        }
-
-        if ( unitsTypeValue < 0 )
-        {
-            unitsTypeValue = m_gridUnit;
-        }
-
-        if ( unitsTypeValue == 2 )
-        {
-            unitsType = RiaDefines::EclipseUnitSystem::UNITS_FIELD;
-        }
-        else if ( unitsTypeValue == 3 )
-        {
-            unitsType = RiaDefines::EclipseUnitSystem::UNITS_LAB;
-        }
+        // Determine final unit system using hierarchy (egrid > init > unrst) with warnings
+        RiaDefines::EclipseUnitSystem unitsType = RifEclipseOutputFileTools::determineUnitSystem( egridUnit, initUnit, unrstUnit );
         m_eclipseCaseData->setUnitsType( unitsType );
     }
 

ApplicationLibCode/FileInterface/RifReaderOpmCommonActive.cpp

@@ -77,13 +77,30 @@ bool RifReaderOpmCommonActive::importGrid( RigMainGrid* /* mainGrid*/, RigEclips
     activeGrid->setDualPorosity( opmGrid.porosity_mode() > 0 );
 
     // assign grid unit, if found (1 = Metric, 2 = Field, 3 = Lab)
+    // Note: Accepts "m" or "M" as abbreviation for "METRES" (METRIC units)
     auto gridUnitStr = RiaStdStringTools::toUpper( opmGrid.grid_unit() );
     if ( gridUnitStr.starts_with( 'M' ) )
+    {
         m_gridUnit = 1;
+        RiaLogging::debug(
+            QString( "Grid unit from EGRID file: '%1' (interpreted as METRIC)" ).arg( QString::fromStdString( opmGrid.grid_unit() ) ) );
+    }
     else if ( gridUnitStr.starts_with( 'F' ) )
+    {
         m_gridUnit = 2;
+        RiaLogging::debug(
+            QString( "Grid unit from EGRID file: '%1' (interpreted as FIELD)" ).arg( QString::fromStdString( opmGrid.grid_unit() ) ) );
+    }
     else if ( gridUnitStr.starts_with( 'C' ) )
+    {
         m_gridUnit = 3;
+        RiaLogging::debug(
+            QString( "Grid unit from EGRID file: '%1' (interpreted as LAB)" ).arg( QString::fromStdString( opmGrid.grid_unit() ) ) );
+    }
+    else if ( !gridUnitStr.empty() )
+    {
+        RiaLogging::warning( QString( "Unknown grid unit from EGRID file: '%1'" ).arg( QString::fromStdString( opmGrid.grid_unit() ) ) );
+    }
 
     auto totalCellCount           = opmGrid.totalNumberOfCells();
     auto totalActiveCellCount     = opmGrid.totalActiveCells();