SimulatorReport SimulatorCompressibleAd::Impl::run(SimulatorTimer& timer,
                                                       BlackoilState& state,
                                                       WellState& well_state)
    {
        std::vector<double> transport_src;

        // Initialisation.
        std::vector<double> porevol;
        if (rock_comp_props_ && rock_comp_props_->isActive()) {
            computePorevolume(grid_, props_.porosity(), *rock_comp_props_, state.pressure(), porevol);
        } else {
            computePorevolume(grid_, props_.porosity(), porevol);
        }
        const double tot_porevol_init = std::accumulate(porevol.begin(), porevol.end(), 0.0);
        std::vector<double> initial_porevol = porevol;

        // Main simulation loop.
        Opm::time::StopWatch pressure_timer;
        double ptime = 0.0;
        Opm::time::StopWatch transport_timer;
        double ttime = 0.0;
        Opm::time::StopWatch step_timer;
        Opm::time::StopWatch total_timer;
        total_timer.start();
        double init_surfvol[2] = { 0.0 };
        double inplace_surfvol[2] = { 0.0 };
        double tot_injected[2] = { 0.0 };
        double tot_produced[2] = { 0.0 };
        Opm::computeSaturatedVol(porevol, state.surfacevol(), init_surfvol);
        Opm::Watercut watercut;
        watercut.push(0.0, 0.0, 0.0);
        Opm::WellReport wellreport;
        std::vector<double> fractional_flows;
        std::vector<double> well_resflows_phase;
        if (wells_) {
            well_resflows_phase.resize((wells_->number_of_phases)*(wells_->number_of_wells), 0.0);
            wellreport.push(props_, *wells_,
                            state.pressure(), state.surfacevol(), state.saturation(),
                            0.0, well_state.bhp(), well_state.perfRates());
        }
        std::fstream tstep_os;
        if (output_) {
            std::string filename = output_dir_ + "/step_timing.param";
            tstep_os.open(filename.c_str(), std::fstream::out | std::fstream::app);
        }
        for (; !timer.done(); ++timer) {
            // Report timestep and (optionally) write state to disk.
            step_timer.start();
            timer.report(std::cout);
            if (output_ && (timer.currentStepNum() % output_interval_ == 0)) {
                if (output_vtk_) {
                    outputStateVtk(grid_, state, timer.currentStepNum(), output_dir_);
                }
                outputStateMatlab(grid_, state, timer.currentStepNum(), output_dir_);
            }

            SimulatorReport sreport;

            // Solve pressure equation.
            if (check_well_controls_) {
                computeFractionalFlow(props_, allcells_,
                                      state.pressure(), state.surfacevol(), state.saturation(),
                                      fractional_flows);
                wells_manager_.applyExplicitReinjectionControls(well_resflows_phase, well_resflows_phase);
            }
            bool well_control_passed = !check_well_controls_;
            int well_control_iteration = 0;
            do {
                // Run solver.
                pressure_timer.start();
                std::vector<double> initial_pressure = state.pressure();
                psolver_.solve(timer.currentStepLength(), state, well_state);

#if 0
                // Renormalize pressure if both fluids and rock are
                // incompressible, and there are no pressure
                // conditions (bcs or wells).  It is deemed sufficient
                // for now to renormalize using geometric volume
                // instead of pore volume.
                if (psolver_.singularPressure()) {
                    // Compute average pressures of previous and last
                    // step, and total volume.
                    double av_prev_press = 0.0;
                    double av_press = 0.0;
                    double tot_vol = 0.0;
                    const int num_cells = grid_.number_of_cells;
                    for (int cell = 0; cell < num_cells; ++cell) {
                        av_prev_press += initial_pressure[cell]*grid_.cell_volumes[cell];
                        av_press      += state.pressure()[cell]*grid_.cell_volumes[cell];
                        tot_vol       += grid_.cell_volumes[cell];
                    }
                    // Renormalization constant
                    const double ren_const = (av_prev_press - av_press)/tot_vol;
                    for (int cell = 0; cell < num_cells; ++cell) {
                        state.pressure()[cell] += ren_const;
                    }
                    const int num_wells = (wells_ == NULL) ? 0 : wells_->number_of_wells;
                    for (int well = 0; well < num_wells; ++well) {
                        well_state.bhp()[well] += ren_const;
                    }
                }
#endif

                // Stop timer and report.
                pressure_timer.stop();
                double pt = pressure_timer.secsSinceStart();
                std::cout << "Pressure solver took:  " << pt << " seconds." << std::endl;
                ptime += pt;
                sreport.pressure_time = pt;

                // Optionally, check if well controls are satisfied.
                if (check_well_controls_) {
                    Opm::computePhaseFlowRatesPerWell(*wells_,
                                                      well_state.perfRates(),
                                                      fractional_flows,
                                                      well_resflows_phase);
                    std::cout << "Checking well conditions." << std::endl;
                    // For testing we set surface := reservoir
                    well_control_passed = wells_manager_.conditionsMet(well_state.bhp(), well_resflows_phase, well_resflows_phase);
                    ++well_control_iteration;
                    if (!well_control_passed && well_control_iteration > max_well_control_iterations_) {
                        THROW("Could not satisfy well conditions in " << max_well_control_iterations_ << " tries.");
                    }
                    if (!well_control_passed) {
                        std::cout << "Well controls not passed, solving again." << std::endl;
                    } else {
                        std::cout << "Well conditions met." << std::endl;
                    }
                }
            } while (!well_control_passed);

            // Update pore volumes if rock is compressible.
            if (rock_comp_props_ && rock_comp_props_->isActive()) {
                initial_porevol = porevol;
                computePorevolume(grid_, props_.porosity(), *rock_comp_props_, state.pressure(), porevol);
            }

            // Process transport sources from well flows.
            Opm::computeTransportSource(props_, wells_, well_state, transport_src);

            // Solve transport.
            transport_timer.start();
            double stepsize = timer.currentStepLength();
            if (num_transport_substeps_ != 1) {
                stepsize /= double(num_transport_substeps_);
                std::cout << "Making " << num_transport_substeps_ << " transport substeps." << std::endl;
            }
            double injected[2] = { 0.0 };
            double produced[2] = { 0.0 };
            for (int tr_substep = 0; tr_substep < num_transport_substeps_; ++tr_substep) {
                tsolver_.solve(&state.faceflux()[0], &state.pressure()[0],
                               &initial_porevol[0], &porevol[0], &transport_src[0], stepsize,
                               state.saturation(), state.surfacevol());
                double substep_injected[2] = { 0.0 };
                double substep_produced[2] = { 0.0 };
                Opm::computeInjectedProduced(props_, state, transport_src, stepsize,
                                             substep_injected, substep_produced);
                injected[0] += substep_injected[0];
                injected[1] += substep_injected[1];
                produced[0] += substep_produced[0];
                produced[1] += substep_produced[1];
                if (gravity_ != 0 && use_segregation_split_) {
                    tsolver_.solveGravity(columns_, stepsize, state.saturation(), state.surfacevol());
                }
            }
            transport_timer.stop();
            double tt = transport_timer.secsSinceStart();
            sreport.transport_time = tt;
            std::cout << "Transport solver took: " << tt << " seconds." << std::endl;
            ttime += tt;
            // Report volume balances.
            Opm::computeSaturatedVol(porevol, state.surfacevol(), inplace_surfvol);
            tot_injected[0] += injected[0];
            tot_injected[1] += injected[1];
            tot_produced[0] += produced[0];
            tot_produced[1] += produced[1];
            std::cout.precision(5);
            const int width = 18;
            std::cout << "\nMass balance report.\n";
            std::cout << "    Injected surface volumes:      "
                      << std::setw(width) << injected[0]
                      << std::setw(width) << injected[1] << std::endl;
            std::cout << "    Produced surface volumes:      "
                      << std::setw(width) << produced[0]
                      << std::setw(width) << produced[1] << std::endl;
            std::cout << "    Total inj surface volumes:     "
                      << std::setw(width) << tot_injected[0]
                      << std::setw(width) << tot_injected[1] << std::endl;
            std::cout << "    Total prod surface volumes:    "
                      << std::setw(width) << tot_produced[0]
                      << std::setw(width) << tot_produced[1] << std::endl;
            const double balance[2] = { init_surfvol[0] - inplace_surfvol[0] - tot_produced[0] + tot_injected[0],
                                        init_surfvol[1] - inplace_surfvol[1] - tot_produced[1] + tot_injected[1] };
            std::cout << "    Initial - inplace + inj - prod: "
                      << std::setw(width) << balance[0]
                      << std::setw(width) << balance[1]
                      << std::endl;
            std::cout << "    Relative mass error:            "
                      << std::setw(width) << balance[0]/(init_surfvol[0] + tot_injected[0])
                      << std::setw(width) << balance[1]/(init_surfvol[1] + tot_injected[1])
                      << std::endl;
            std::cout.precision(8);

            watercut.push(timer.currentTime() + timer.currentStepLength(),
                          produced[0]/(produced[0] + produced[1]),
                          tot_produced[0]/tot_porevol_init);
            if (wells_) {
                wellreport.push(props_, *wells_,
                                state.pressure(), state.surfacevol(), state.saturation(),
                                timer.currentTime() + timer.currentStepLength(),
                                well_state.bhp(), well_state.perfRates());
            }
            sreport.total_time =  step_timer.secsSinceStart();
            if (output_) {
                sreport.reportParam(tstep_os);
            }
        }

        if (output_) {
            if (output_vtk_) {
                outputStateVtk(grid_, state, timer.currentStepNum(), output_dir_);
            }
            outputStateMatlab(grid_, state, timer.currentStepNum(), output_dir_);
            outputWaterCut(watercut, output_dir_);
            if (wells_) {
                outputWellReport(wellreport, output_dir_);
            }
            tstep_os.close();
        }

        total_timer.stop();

        SimulatorReport report;
        report.pressure_time = ptime;
        report.transport_time = ttime;
        report.total_time = total_timer.secsSinceStart();
        return report;
    }
    SimulatorReport SimulatorCompressiblePolymer::Impl::run(SimulatorTimer& timer,
                                                            PolymerBlackoilState& state,
                                                            WellState& well_state)
    {
        std::vector<double> transport_src(grid_.number_of_cells);
        std::vector<double> polymer_inflow_c(grid_.number_of_cells);

        // Initialisation.
        std::vector<double> initial_pressure;
        std::vector<double> porevol;
        if (rock_comp_props_ && rock_comp_props_->isActive()) {
            computePorevolume(grid_, props_.porosity(), *rock_comp_props_, state.pressure(), porevol);
        } else {
            computePorevolume(grid_, props_.porosity(), porevol);
        }
        const double tot_porevol_init = std::accumulate(porevol.begin(), porevol.end(), 0.0);
        std::vector<double> initial_porevol = porevol;

        // Main simulation loop.
        Opm::time::StopWatch pressure_timer;
        double ptime = 0.0;
        Opm::time::StopWatch transport_timer;
        double ttime = 0.0;
        Opm::time::StopWatch total_timer;
        total_timer.start();
        double init_surfvol[2] = { 0.0 };
        double inplace_surfvol[2] = { 0.0 };
        double polymass = computePolymerMass(porevol, state.saturation(), state.getCellData( state.CONCENTRATION ), poly_props_.deadPoreVol());
        double polymass_adsorbed = computePolymerAdsorbed(grid_, props_, poly_props_, state, rock_comp_props_);
        double init_polymass = polymass + polymass_adsorbed;
        double tot_injected[2] = { 0.0 };
        double tot_produced[2] = { 0.0 };
        double tot_polyinj = 0.0;
        double tot_polyprod = 0.0;
        Opm::computeSaturatedVol(porevol, state.surfacevol(), init_surfvol);
        Opm::Watercut watercut;
        watercut.push(0.0, 0.0, 0.0);
        Opm::WellReport wellreport;
        std::vector<double> fractional_flows;
        std::vector<double> well_resflows_phase;
        if (wells_) {
            well_resflows_phase.resize((wells_->number_of_phases)*(wells_->number_of_wells), 0.0);
            wellreport.push(props_, *wells_, state.pressure(), state.surfacevol(),
                            state.saturation(), 0.0, well_state.bhp(), well_state.perfRates());
        }
        // Report timestep and (optionally) write state to disk.
        timer.report(std::cout);
        if (output_ && (timer.currentStepNum() % output_interval_ == 0)) {
            if (output_vtk_) {
                outputStateVtk(grid_, state, timer.currentStepNum(), output_dir_);
            }
            outputStateMatlab(grid_, state, timer.currentStepNum(), output_dir_);
        }

        initial_pressure = state.pressure();

        // Solve pressure equation.
        if (check_well_controls_) {
            computeFractionalFlow(props_, poly_props_, allcells_,
                                  state.pressure(), state.temperature(), state.surfacevol(), state.saturation(),
                                  state.getCellData( state.CONCENTRATION ), state.getCellData( state.CMAX ) ,
                                  fractional_flows);
            wells_manager_.applyExplicitReinjectionControls(well_resflows_phase, well_resflows_phase);
        }
        bool well_control_passed = !check_well_controls_;
        int well_control_iteration = 0;
        do {
            // Run solver
            pressure_timer.start();
            psolver_.solve(timer.currentStepLength(), state, well_state);

            // Renormalize pressure if both fluids and rock are
            // incompressible, and there are no pressure
            // conditions (bcs or wells).  It is deemed sufficient
            // for now to renormalize using geometric volume
            // instead of pore volume.
            if (psolver_.singularPressure()) {
                // Compute average pressures of previous and last
                // step, and total volume.
                double av_prev_press = 0.0;
                double av_press = 0.0;
                double tot_vol = 0.0;
                const int num_cells = grid_.number_of_cells;
                for (int cell = 0; cell < num_cells; ++cell) {
                    av_prev_press += initial_pressure[cell]*grid_.cell_volumes[cell];
                    av_press      += state.pressure()[cell]*grid_.cell_volumes[cell];
                    tot_vol       += grid_.cell_volumes[cell];
                }
                // Renormalization constant
                const double ren_const = (av_prev_press - av_press)/tot_vol;
                for (int cell = 0; cell < num_cells; ++cell) {
                    state.pressure()[cell] += ren_const;
                }
                const int num_wells = (wells_ == NULL) ? 0 : wells_->number_of_wells;
                for (int well = 0; well < num_wells; ++well) {
                    well_state.bhp()[well] += ren_const;
                }
            }

            // Stop timer and report
            pressure_timer.stop();
            double pt = pressure_timer.secsSinceStart();
            std::cout << "Pressure solver took:  " << pt << " seconds." << std::endl;
            ptime += pt;

            // Optionally, check if well controls are satisfied.
            if (check_well_controls_) {
                Opm::computePhaseFlowRatesPerWell(*wells_,
                                                  well_state.perfRates(),
                                                  fractional_flows,
                                                  well_resflows_phase);
                std::cout << "Checking well conditions." << std::endl;
                // For testing we set surface := reservoir
                well_control_passed = wells_manager_.conditionsMet(well_state.bhp(), well_resflows_phase, well_resflows_phase);
                ++well_control_iteration;
                if (!well_control_passed && well_control_iteration > max_well_control_iterations_) {
                    OPM_THROW(std::runtime_error, "Could not satisfy well conditions in " << max_well_control_iterations_ << " tries.");
                }
                if (!well_control_passed) {
                    std::cout << "Well controls not passed, solving again." << std::endl;
                } else {
                    std::cout << "Well conditions met." << std::endl;
                }
            }
        } while (!well_control_passed);

        // Update pore volumes if rock is compressible.
        if (rock_comp_props_ && rock_comp_props_->isActive()) {
            initial_porevol = porevol;
            computePorevolume(grid_, props_.porosity(), *rock_comp_props_, state.pressure(), porevol);
        }

        // Process transport sources (to include bdy terms and well flows).
        Opm::computeTransportSource(props_, wells_, well_state, transport_src);

        // Find inflow rate.
        const double current_time = timer.simulationTimeElapsed();
        double stepsize = timer.currentStepLength();
        polymer_inflow_.getInflowValues(current_time, current_time + stepsize, polymer_inflow_c);


        // Solve transport.
        transport_timer.start();
        if (num_transport_substeps_ != 1) {
            stepsize /= double(num_transport_substeps_);
            std::cout << "Making " << num_transport_substeps_ << " transport substeps." << std::endl;
        }
        double injected[2] = { 0.0 };
        double produced[2] = { 0.0 };
        double polyinj = 0.0;
        double polyprod = 0.0;
        for (int tr_substep = 0; tr_substep < num_transport_substeps_; ++tr_substep) {
            tsolver_.solve(&state.faceflux()[0], initial_pressure,
                           state.pressure(), state.temperature(), &initial_porevol[0], &porevol[0],
                           &transport_src[0], &polymer_inflow_c[0], stepsize,
                           state.saturation(), state.surfacevol(),
                           state.getCellData( state.CONCENTRATION ), state.getCellData( state.CMAX ));
            double substep_injected[2] = { 0.0 };
            double substep_produced[2] = { 0.0 };
            double substep_polyinj = 0.0;
            double substep_polyprod = 0.0;
            Opm::computeInjectedProduced(props_, poly_props_,
                                         state,
                                         transport_src, polymer_inflow_c, stepsize,
                                         substep_injected, substep_produced,
                                         substep_polyinj, substep_polyprod);
            injected[0] += substep_injected[0];
            injected[1] += substep_injected[1];
            produced[0] += substep_produced[0];
            produced[1] += substep_produced[1];
            polyinj += substep_polyinj;
            polyprod += substep_polyprod;
            if (gravity_ != 0 && use_segregation_split_) {
                tsolver_.solveGravity(columns_, stepsize,
                                      state.saturation(), state.surfacevol(),
                                      state.getCellData( state.CONCENTRATION ), state.getCellData( state.CMAX ));
            }
        }
        transport_timer.stop();
        double tt = transport_timer.secsSinceStart();
        std::cout << "Transport solver took: " << tt << " seconds." << std::endl;
        ttime += tt;

        // Report volume balances.
        Opm::computeSaturatedVol(porevol, state.surfacevol(), inplace_surfvol);
        polymass = Opm::computePolymerMass(porevol, state.saturation(), state.getCellData( state.CONCENTRATION ), poly_props_.deadPoreVol());
        polymass_adsorbed = Opm::computePolymerAdsorbed(grid_, props_, poly_props_,
                                                        state, rock_comp_props_);
        tot_injected[0] += injected[0];
        tot_injected[1] += injected[1];
        tot_produced[0] += produced[0];
        tot_produced[1] += produced[1];
        tot_polyinj += polyinj;
        tot_polyprod += polyprod;
        std::cout.precision(5);
        const int width = 18;
        std::cout << "\nMass balance:        "
            "                   water(surfvol)      oil(surfvol)       polymer(kg)\n";
        std::cout << "    In-place:                       "
                  << std::setw(width) << inplace_surfvol[0]
                  << std::setw(width) << inplace_surfvol[1]
                  << std::setw(width) << polymass << std::endl;
        std::cout << "    Adsorbed:                       "
                  << std::setw(width) << 0.0
                  << std::setw(width) << 0.0
                  << std::setw(width) << polymass_adsorbed << std::endl;
        std::cout << "    Injected:                       "
                  << std::setw(width) << injected[0]
                  << std::setw(width) << injected[1]
                  << std::setw(width) << polyinj << std::endl;
        std::cout << "    Produced:                       "
                  << std::setw(width) << produced[0]
                  << std::setw(width) << produced[1]
                  << std::setw(width) << polyprod << std::endl;
        std::cout << "    Total inj:                      "
                  << std::setw(width) << tot_injected[0]
                  << std::setw(width) << tot_injected[1]
                  << std::setw(width) << tot_polyinj << std::endl;
        std::cout << "    Total prod:                     "
                  << std::setw(width) << tot_produced[0]
                  << std::setw(width) << tot_produced[1]
                  << std::setw(width) << tot_polyprod << std::endl;
        const double balance[3] = { init_surfvol[0] - inplace_surfvol[0] - tot_produced[0] + tot_injected[0],
                                    init_surfvol[1] - inplace_surfvol[1] - tot_produced[1] + tot_injected[1],
                                    init_polymass - polymass - tot_polyprod + tot_polyinj - polymass_adsorbed };
        std::cout << "    Initial - inplace + inj - prod: "
                  << std::setw(width) << balance[0]
                  << std::setw(width) << balance[1]
                  << std::setw(width) << balance[2]
                  << std::endl;
        std::cout << "    Relative mass error:            "
                  << std::setw(width) << balance[0]/(init_surfvol[0] + tot_injected[0])
                  << std::setw(width) << balance[1]/(init_surfvol[1] + tot_injected[1])
                  << std::setw(width) << balance[2]/(init_polymass + tot_polyinj)
                  << std::endl;
        std::cout.precision(8);

        watercut.push(timer.simulationTimeElapsed() + timer.currentStepLength(),
                      produced[0]/(produced[0] + produced[1]),
                      tot_produced[0]/tot_porevol_init);
        if (wells_) {
        wellreport.push(props_, *wells_, state.pressure(), state.surfacevol(),
                        state.saturation(), timer.simulationTimeElapsed() + timer.currentStepLength(),
                        well_state.bhp(), well_state.perfRates());
        }

        if (output_) {
            if (output_vtk_) {
                outputStateVtk(grid_, state, timer.currentStepNum(), output_dir_);
            }
            outputStateMatlab(grid_, state, timer.currentStepNum(), output_dir_);
            outputWaterCut(watercut, output_dir_);
            if (wells_) {
                outputWellReport(wellreport, output_dir_);
            }
        }

        total_timer.stop();

        SimulatorReport report;
        report.pressure_time = ptime;
        report.transport_time = ttime;
        report.total_time = total_timer.secsSinceStart();
        return report;
    }
Example #3
0
    SimulatorReport SimulatorIncompTwophase::Impl::run(SimulatorTimer& timer,
                                                       TwophaseState& state,
                                                       WellState& well_state)
    {
        std::vector<double> transport_src;

        // Initialisation.
        std::vector<double> porevol;
        if (rock_comp_props_ && rock_comp_props_->isActive()) {
            computePorevolume(grid_, props_.porosity(), *rock_comp_props_, state.pressure(), porevol);
        } else {
            computePorevolume(grid_, props_.porosity(), porevol);
        }
        const double tot_porevol_init = std::accumulate(porevol.begin(), porevol.end(), 0.0);
        std::vector<double> initial_porevol = porevol;

        // Main simulation loop.
        Opm::time::StopWatch pressure_timer;
        double ptime = 0.0;
        Opm::time::StopWatch transport_timer;
        double ttime = 0.0;
        Opm::time::StopWatch callback_timer;
        double time_in_callbacks = 0.0;
        Opm::time::StopWatch step_timer;
        Opm::time::StopWatch total_timer;
        total_timer.start();
        double init_satvol[2] = { 0.0 };
        double satvol[2] = { 0.0 };
        double tot_injected[2] = { 0.0 };
        double tot_produced[2] = { 0.0 };
        Opm::computeSaturatedVol(porevol, state.saturation(), init_satvol);
        *log_ << "\nInitial saturations are    " << init_satvol[0]/tot_porevol_init
              << "    " << init_satvol[1]/tot_porevol_init << std::endl;
        Opm::Watercut watercut;
        watercut.push(0.0, 0.0, 0.0);
        Opm::WellReport wellreport;
        std::vector<double> fractional_flows;
        std::vector<double> well_resflows_phase;
        if (wells_) {
            well_resflows_phase.resize((wells_->number_of_phases)*(wells_->number_of_wells), 0.0);
            wellreport.push(props_, *wells_, state.saturation(), 0.0, well_state.bhp(), well_state.perfRates());
        }
        std::fstream tstep_os;
        if (output_) {
            std::string filename = output_dir_ + "/step_timing.param";
            tstep_os.open(filename.c_str(), std::fstream::out | std::fstream::app);
        }
        while (!timer.done()) {
            // Report timestep and (optionally) write state to disk.
            step_timer.start();
            timer.report(*log_);
            if (output_ && (timer.currentStepNum() % output_interval_ == 0)) {
                if (output_vtk_) {
                    outputStateVtk(grid_, state, timer.currentStepNum(), output_dir_);
                }
                outputStateMatlab(grid_, state, timer.currentStepNum(), output_dir_);
                if (use_reorder_) {
                    // This use of dynamic_cast is not ideal, but should be safe.
                    outputVectorMatlab(std::string("reorder_it"),
                                       dynamic_cast<const TransportSolverTwophaseReorder&>(*tsolver_).getReorderIterations(),
                                       timer.currentStepNum(), output_dir_);
                }
            }

            SimulatorReport sreport;

            // Solve pressure equation.
            if (check_well_controls_) {
                computeFractionalFlow(props_, allcells_, state.saturation(), fractional_flows);
                wells_manager_.applyExplicitReinjectionControls(well_resflows_phase, well_resflows_phase);
            }
            bool well_control_passed = !check_well_controls_;
            int well_control_iteration = 0;
            do {
                // Run solver.
                pressure_timer.start();
                std::vector<double> initial_pressure = state.pressure();
                psolver_.solve(timer.currentStepLength(), state, well_state);

                // Renormalize pressure if rock is incompressible, and
                // there are no pressure conditions (bcs or wells).
                // It is deemed sufficient for now to renormalize
                // using geometric volume instead of pore volume.
                if ((rock_comp_props_ == NULL || !rock_comp_props_->isActive())
                    && allNeumannBCs(bcs_) && allRateWells(wells_)) {
                    // Compute average pressures of previous and last
                    // step, and total volume.
                    double av_prev_press = 0.0;
                    double av_press = 0.0;
                    double tot_vol = 0.0;
                    const int num_cells = grid_.number_of_cells;
                    for (int cell = 0; cell < num_cells; ++cell) {
                        av_prev_press += initial_pressure[cell]*grid_.cell_volumes[cell];
                        av_press      += state.pressure()[cell]*grid_.cell_volumes[cell];
                        tot_vol       += grid_.cell_volumes[cell];
                    }
                    // Renormalization constant
                    const double ren_const = (av_prev_press - av_press)/tot_vol;
                    for (int cell = 0; cell < num_cells; ++cell) {
                        state.pressure()[cell] += ren_const;
                    }
                    const int num_wells = (wells_ == NULL) ? 0 : wells_->number_of_wells;
                    for (int well = 0; well < num_wells; ++well) {
                        well_state.bhp()[well] += ren_const;
                    }
                }

                // Stop timer and report.
                pressure_timer.stop();
                double pt = pressure_timer.secsSinceStart();
                *log_ << "Pressure solver took:  " << pt << " seconds." << std::endl;
                ptime += pt;
                sreport.pressure_time = pt;

                // Optionally, check if well controls are satisfied.
                if (check_well_controls_) {
                    Opm::computePhaseFlowRatesPerWell(*wells_,
                                                      well_state.perfRates(),
                                                      fractional_flows,
                                                      well_resflows_phase);
                    *log_ << "Checking well conditions." << std::endl;
                    // For testing we set surface := reservoir
                    well_control_passed = wells_manager_.conditionsMet(well_state.bhp(), well_resflows_phase, well_resflows_phase);
                    ++well_control_iteration;
                    if (!well_control_passed && well_control_iteration > max_well_control_iterations_) {
                        OPM_THROW(std::runtime_error, "Could not satisfy well conditions in " << max_well_control_iterations_ << " tries.");
                    }
                    if (!well_control_passed) {
                        *log_ << "Well controls not passed, solving again." << std::endl;
                    } else {
                        *log_ << "Well conditions met." << std::endl;
                    }
                }
            } while (!well_control_passed);

            // Update pore volumes if rock is compressible.
            if (rock_comp_props_ && rock_comp_props_->isActive()) {
                initial_porevol = porevol;
                computePorevolume(grid_, props_.porosity(), *rock_comp_props_, state.pressure(), porevol);
            }

            // Process transport sources (to include bdy terms and well flows).
            Opm::computeTransportSource(grid_, src_, state.faceflux(), 1.0,
                                        wells_, well_state.perfRates(), transport_src);

            // Solve transport.
            transport_timer.start();
            double stepsize = timer.currentStepLength();
            if (num_transport_substeps_ != 1) {
                stepsize /= double(num_transport_substeps_);
                *log_ << "Making " << num_transport_substeps_ << " transport substeps." << std::endl;
            }
            double injected[2] = { 0.0 };
            double produced[2] = { 0.0 };
            for (int tr_substep = 0; tr_substep < num_transport_substeps_; ++tr_substep) {
                tsolver_->solve(&initial_porevol[0], &transport_src[0], stepsize, state);

                double substep_injected[2] = { 0.0 };
                double substep_produced[2] = { 0.0 };
                Opm::computeInjectedProduced(props_, state.saturation(), transport_src, stepsize,
                                             substep_injected, substep_produced);
                injected[0] += substep_injected[0];
                injected[1] += substep_injected[1];
                produced[0] += substep_produced[0];
                produced[1] += substep_produced[1];
                if (use_reorder_ && use_segregation_split_) {
                    // Again, unfortunate but safe use of dynamic_cast.
                    // Possible solution: refactor gravity solver to its own class.
                    dynamic_cast<TransportSolverTwophaseReorder&>(*tsolver_)
                        .solveGravity(&initial_porevol[0], stepsize, state);
                }
                watercut.push(timer.simulationTimeElapsed() + timer.currentStepLength(),
                              produced[0]/(produced[0] + produced[1]),
                              tot_produced[0]/tot_porevol_init);
                if (wells_) {
                    wellreport.push(props_, *wells_, state.saturation(),
                                    timer.simulationTimeElapsed() + timer.currentStepLength(),
                                    well_state.bhp(), well_state.perfRates());
                }
            }
            transport_timer.stop();
            double tt = transport_timer.secsSinceStart();
            sreport.transport_time = tt;
            *log_ << "Transport solver took: " << tt << " seconds." << std::endl;
            ttime += tt;
            // Report volume balances.
            Opm::computeSaturatedVol(porevol, state.saturation(), satvol);
            tot_injected[0] += injected[0];
            tot_injected[1] += injected[1];
            tot_produced[0] += produced[0];
            tot_produced[1] += produced[1];
            reportVolumes(*log_, satvol, tot_porevol_init,
                          tot_injected, tot_produced,
                          injected, produced,
                          init_satvol);
            sreport.total_time =  step_timer.secsSinceStart();
            if (output_) {
                sreport.reportParam(tstep_os);
            }

            // advance the timer to the end of the timestep *before* notifying
            // the client that the timestep is done
            ++timer;

            // notify all clients that we are done with the timestep
            callback_timer.start ();
            timestep_completed_.signal ();
            callback_timer.stop ();
            time_in_callbacks += callback_timer.secsSinceStart ();
        }

        if (output_) {
            if (output_vtk_) {
                outputStateVtk(grid_, state, timer.currentStepNum(), output_dir_);
            }
            outputStateMatlab(grid_, state, timer.currentStepNum(), output_dir_);
            if (use_reorder_) {
                // This use of dynamic_cast is not ideal, but should be safe.
                outputVectorMatlab(std::string("reorder_it"),
                                   dynamic_cast<const TransportSolverTwophaseReorder&>(*tsolver_).getReorderIterations(),
                                   timer.currentStepNum(), output_dir_);
                }
            outputWaterCut(watercut, output_dir_);
            if (wells_) {
                outputWellReport(wellreport, output_dir_);
            }
            tstep_os.close();
        }

        total_timer.stop();

        SimulatorReport report;
        report.pressure_time = ptime;
        report.transport_time = ttime;
        report.total_time = total_timer.secsSinceStart() - time_in_callbacks;
        return report;
    }