#6526 Fracture Model: Make TVD/MD values consistent in Deviation.FRK

The change in measured depth (MD) must be greater or equal to change in
true vertical depth (TVD), and this was not always the case due to
interpolation imprecision.

ApplicationCode/FileInterface/RifFractureModelDeviationFrkExporter.cpp

@@ -61,11 +61,15 @@ bool RifFractureModelDeviationFrkExporter::writeToFile( RimFractureModelPlot* pl
     std::vector<double> mdValues;
     RigWellPathGeometryExporter::exportWellPathGeometry( wellPath, mdStepSize, xValues, yValues, tvdValues, mdValues, useMdRkb );
 
-    convertFromMeterToFeet( mdValues );
-    convertFromMeterToFeet( tvdValues );
+    std::vector<double> exportTvdValues;
+    std::vector<double> exportMdValues;
+    fixupDepthValuesForExport( tvdValues, mdValues, exportTvdValues, exportMdValues );
 
-    appendToStream( stream, "mdArray", mdValues );
-    appendToStream( stream, "tvdArray", tvdValues );
+    convertFromMeterToFeet( exportMdValues );
+    convertFromMeterToFeet( exportTvdValues );
+
+    appendToStream( stream, "mdArray", exportMdValues );
+    appendToStream( stream, "tvdArray", exportTvdValues );
 
     appendFooterToStream( stream );
 
@@ -124,3 +128,37 @@ void RifFractureModelDeviationFrkExporter::convertFromMeterToFeet( std::vector<d
         data[i] = RiaEclipseUnitTools::meterToFeet( data[i] );
     }
 }
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+void RifFractureModelDeviationFrkExporter::fixupDepthValuesForExport( const std::vector<double>& tvdValues,
+                                                                      const std::vector<double>& mdValues,
+                                                                      std::vector<double>&       exportTvdValues,
+                                                                      std::vector<double>&       exportMdValues )
+{
+    if ( tvdValues.empty() || mdValues.empty() ) return;
+
+    exportMdValues.push_back( mdValues[0] );
+    exportTvdValues.push_back( tvdValues[0] );
+
+    for ( size_t i = 1; i < tvdValues.size(); i++ )
+    {
+        double changeMd  = mdValues[i] - exportMdValues[i - 1];
+        double changeTvd = tvdValues[i] - exportTvdValues[i - 1];
+
+        // Stimplan checks that the change in MD is larger than or equal to change in TVD.
+        // This condition is not always satisfied due to the interpolation of TVDs.
+        // Move the MD value to produce a file which can be imported.
+        if ( changeMd < changeTvd )
+        {
+            exportMdValues.push_back( exportMdValues[i - 1] + changeTvd );
+        }
+        else
+        {
+            exportMdValues.push_back( mdValues[i] );
+        }
+
+        exportTvdValues.push_back( tvdValues[i] );
+    }
+}

ApplicationCode/FileInterface/RifFractureModelDeviationFrkExporter.h

@@ -32,6 +32,11 @@ class RifFractureModelDeviationFrkExporter
 public:
     static bool writeToFile( RimFractureModelPlot* plot, const QString& filepath );
 
+    static void fixupDepthValuesForExport( const std::vector<double>& tvdValues,
+                                           const std::vector<double>& mdValues,
+                                           std::vector<double>&       exportTvdValues,
+                                           std::vector<double>&       exportMdValues );
+
 private:
     static void appendHeaderToStream( QTextStream& stream );
     static void appendToStream( QTextStream& stream, const QString& label, const std::vector<double>& values );

ApplicationCode/UnitTests/CMakeLists_files.cmake

@@ -73,6 +73,7 @@ ${CMAKE_CURRENT_LIST_DIR}/RifElasticPropertiesReader-Test.cpp
 ${CMAKE_CURRENT_LIST_DIR}/RiaStatisticsTools-Test.cpp
 ${CMAKE_CURRENT_LIST_DIR}/RifStimPlanXmlReader-Test.cpp
 ${CMAKE_CURRENT_LIST_DIR}/RigWellPathGeometryExporter-Test.cpp
+${CMAKE_CURRENT_LIST_DIR}/RifFractureModelDeviationFrkExporter-Test.cpp
 )
 
 if (RESINSIGHT_ENABLE_GRPC)

ApplicationCode/UnitTests/RifFractureModelDeviationFrkExporter-Test.cpp

@@ -0,0 +1,29 @@
+#include "gtest/gtest.h"
+
+#include "RifFractureModelDeviationFrkExporter.h"
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+TEST( RifFractureModelDeviationFrkExporterTest, TvdFixup )
+{
+    std::vector<double> tvd =
+        {475.722, 492.126, 508.53, 524.934, 541.338, 557.743, 574.147, 590.551, 606.955, 623.359, 639.764, 656.168, 672.572};
+    std::vector<double> md =
+        {475.722, 492.126, 508.53, 524.934, 541.339, 557.743, 574.147, 590.551, 606.955, 623.36, 639.764, 656.168, 672.572};
+
+    std::vector<double> exportTvd;
+    std::vector<double> exportMd;
+
+    RifFractureModelDeviationFrkExporter::fixupDepthValuesForExport( tvd, md, exportTvd, exportMd );
+
+    EXPECT_EQ( tvd.size(), exportTvd.size() );
+    EXPECT_EQ( md.size(), exportMd.size() );
+
+    for ( size_t i = 1; i < exportMd.size(); i++ )
+    {
+        double changeMd  = exportMd[i] - exportMd[i - 1];
+        double changeTvd = exportTvd[i] - exportTvd[i - 1];
+        ASSERT_GE( changeMd, changeTvd );
+    }
+}