diff --git a/opm/autodiff/StandardWellsDense.hpp b/opm/autodiff/StandardWellsDense.hpp
index 8a7368977..50285c64e 100644
--- a/opm/autodiff/StandardWellsDense.hpp
+++ b/opm/autodiff/StandardWellsDense.hpp
@@ -310,6 +310,9 @@ enum WellVariablePositions {
 
             EvalWell wellVolumeFractionScaled(const int wellIdx, const int phaseIdx) const;
 
+            // Q_p / (Q_w + Q_g + Q_o) for three phase cases.
+            EvalWell wellSurfaceVolumeFraction(const int well_index, const int phase) const;
+
             bool checkRateEconLimits(const WellEconProductionLimits& econ_production_limits,
                                      const WellState& well_state,
                                      const int well_number) const;
diff --git a/opm/autodiff/StandardWellsDense_impl.hpp b/opm/autodiff/StandardWellsDense_impl.hpp
index 6a7fb2133..f5f8c65e8 100644
--- a/opm/autodiff/StandardWellsDense_impl.hpp
+++ b/opm/autodiff/StandardWellsDense_impl.hpp
@@ -2076,6 +2076,26 @@ namespace Opm {
 
 
 
+    template<typename FluidSystem, typename BlackoilIndices>
+    typename StandardWellsDense<FluidSystem, BlackoilIndices>::EvalWell
+    StandardWellsDense<FluidSystem, BlackoilIndices>::
+    wellSurfaceVolumeFraction(const int well_index, const int phase) const
+    {
+        EvalWell sum_volume_fraction_scaled = 0.;
+        const int np = wells().number_of_phases;
+        for (int p = 0; p < np; ++p) {
+            sum_volume_fraction_scaled += wellVolumeFractionScaled(well_index, p);
+        }
+
+        assert(sum_volume_fraction_scaled.value() != 0.);
+
+        return wellVolumeFractionScaled(well_index, phase) / sum_volume_fraction_scaled;
+    }
+
+
+
+
+
     template<typename FluidSystem, typename BlackoilIndices>
     bool
     StandardWellsDense<FluidSystem, BlackoilIndices>::