diff --git a/opm/autodiff/BlackoilModelEbos.hpp b/opm/autodiff/BlackoilModelEbos.hpp
index b125ee317..3c320210c 100644
--- a/opm/autodiff/BlackoilModelEbos.hpp
+++ b/opm/autodiff/BlackoilModelEbos.hpp
@@ -213,8 +213,9 @@ namespace Opm {
         /// \param[in, out] well_state        well state variables
         void prepareStep(const SimulatorTimerInterface& /*timer*/,
                          const ReservoirState& /*reservoir_state*/,
-                         const WellState& /* well_state */)
+                         WellState& well_state)
         {
+            well_model_.prepareTimeStep(ebosSimulator_, well_state);
         }
 
 
diff --git a/opm/autodiff/NonlinearSolver_impl.hpp b/opm/autodiff/NonlinearSolver_impl.hpp
index 6c64f4cd0..9062ad5b0 100644
--- a/opm/autodiff/NonlinearSolver_impl.hpp
+++ b/opm/autodiff/NonlinearSolver_impl.hpp
@@ -127,7 +127,11 @@ namespace Opm
         failureReport_ = SimulatorReport();
 
         // Do model-specific once-per-step calculations.
-        model_->prepareStep(timer, initial_reservoir_state, initial_well_state);
+        // TODO: this is not the correct fix, possibly breaking the sequential solver
+        // TODO: the only reason to do this is that the wellPotentials() is part of the well_state, which will be modified
+        // during the well_potential calculation
+        model_->prepareStep(timer, initial_reservoir_state, well_state);
+        // model_->prepareStep(timer, initial_reservoir_state, initial_reservoir_state);
 
         int iteration = 0;
 
diff --git a/opm/autodiff/StandardWellsDense.hpp b/opm/autodiff/StandardWellsDense.hpp
index 38f769025..ca415a265 100644
--- a/opm/autodiff/StandardWellsDense.hpp
+++ b/opm/autodiff/StandardWellsDense.hpp
@@ -251,11 +251,16 @@ enum WellVariablePositions {
             computeWellPotentials(const Simulator& ebosSimulator,
                                   WellState& well_state)  const;
 
-
             // TODO: temporary function name for now before changing the simulator and also WellsMananger
             void computeWellPotentials(const WellState& well_state,
                                        std::vector<double>& well_potentials) const;
 
+            // TODO: some preparation work, mostly related to group control and RESV,
+            // at the beginning of each time step (Not report step)
+            template<typename Simulator>
+            void prepareTimeStep(const Simulator& ebos_simulator,
+                                 WellState& well_state);
+
             WellCollection* wellCollection() const;
 
             const std::vector<double>&
diff --git a/opm/autodiff/StandardWellsDense_impl.hpp b/opm/autodiff/StandardWellsDense_impl.hpp
index 92739cd19..ad7b6e11f 100644
--- a/opm/autodiff/StandardWellsDense_impl.hpp
+++ b/opm/autodiff/StandardWellsDense_impl.hpp
@@ -1834,7 +1834,45 @@ namespace Opm {
 
 
 
-    template<typename FluidSystem, typename BlackoilIndices, typename ElementContext, typename MaterialLaw>
+    template<typename FluidSystem, typename BlackoilIndices, typename ElementContext>
+    template<typename Simulator>
+    void
+    StandardWellsDense<FluidSystem, BlackoilIndices>::
+    prepareTimeStep(const Simulator& ebos_simulator,
+                    WellState& well_state)
+    {
+
+        // TODO: we should remove the wellPotentials() from the well_state.
+
+        if (well_collection_->groupControlActive()) {
+            // calculate the well potentials
+            // two functions will probably be merged in the final version
+            // and also the well potentials related parts in well state.
+            if (param_.compute_well_potentials_) {
+                setWellVariables(well_state);
+                computeWellConnectionPressures(ebos_simulator, well_state);
+
+                computeWellPotentials(ebos_simulator, well_state);
+
+                // To store well potentials for each well
+                std::vector<double> well_potentials;
+
+                computeWellPotentials(well_state, well_potentials);
+
+                // update/setup guide rates for each well based on the well_potentials
+                well_collection_->setGuideRates(wellsPointer(), phase_usage_, well_potentials);
+            }
+            applyVREPGroupControl(well_state);
+            wellCollection()->updateWellTargets(well_state.wellRates());
+        }
+    }
+
+
+
+
+
+
+    template<typename FluidSystem, typename BlackoilIndices, typename ElementContext>
     WellCollection*
     StandardWellsDense<FluidSystem, BlackoilIndices, ElementContext, MaterialLaw>::
     wellCollection() const