opm-simulators/opm/autodiff/MultisegmentWells_impl.hpp
Tor Harald Sandve 6084721812 Prepare for extended models.
Let the code loop over number of components instead of phase
Pass TypeTag as template parameter instead of all the properties.
2017-05-08 09:52:30 +02:00

1179 lines
52 KiB
C++

/*
Copyright 2016 SINTEF ICT, Applied Mathematics.
Copyright 2016 Statoil ASA.
This file is part of the Open Porous Media project (OPM).
OPM is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
OPM is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with OPM. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef OPM_MULTISEGMENTWELLS_IMPL_HEADER_INCLUDED
#define OPM_MULTISEGMENTWELLS_IMPL_HEADER_INCLUDED
namespace Opm
{
namespace wellhelpers {
using ADB = MultisegmentWells::ADB;
using Vector = MultisegmentWells::Vector;
inline
ADB onlyWellDerivs(const ADB& x)
{
Vector val = x.value();
const int nb = x.numBlocks();
if (nb < 2) {
OPM_THROW(std::logic_error, "Called onlyWellDerivs() with argument that has " << nb << " blocks.");
}
std::vector<ADB::M> derivs = { x.derivative()[nb - 2], x.derivative()[nb - 1] };
return ADB::function(std::move(val), std::move(derivs));
}
}
template <class ReservoirResidualQuant, class SolutionState>
void
MultisegmentWells::
extractWellPerfProperties(const SolutionState& /* state */,
const std::vector<ReservoirResidualQuant>& rq,
std::vector<ADB>& mob_perfcells,
std::vector<ADB>& b_perfcells) const
{
// If we have wells, extract the mobilities and b-factors for
// the well-perforated cells.
if ( !localWellsActive() ) {
mob_perfcells.clear();
b_perfcells.clear();
return;
} else {
const std::vector<int>& well_cells = wellOps().well_cells;
mob_perfcells.resize(num_phases_, ADB::null());
b_perfcells.resize(num_phases_, ADB::null());
for (int phase = 0; phase < num_phases_; ++phase) {
mob_perfcells[phase] = subset(rq[phase].mob, well_cells);
b_perfcells[phase] = subset(rq[phase].b, well_cells);
}
}
}
template <class WellState>
void
MultisegmentWells::
updateWellState(const Vector& dwells,
const double dpmaxrel,
WellState& well_state) const
{
if (!msWells().empty())
{
const int nw = msWells().size();
const int nseg_total = nseg_total_;
const int np = numPhases();
// Extract parts of dwells corresponding to each part.
int varstart = 0;
const Vector dsegqs = subset(dwells, Span(np * nseg_total, 1, varstart));
varstart += dsegqs.size();
const Vector dsegp = subset(dwells, Span(nseg_total, 1, varstart));
varstart += dsegp.size();
assert(varstart == dwells.size());
// segment phase rates update
// in dwells, the phase rates are ordered by phase.
// while in WellStateMultiSegment, the phase rates are ordered by segments
const DataBlock wsr = Eigen::Map<const DataBlock>(dsegqs.data(), np, nseg_total).transpose();
const Vector dwsr = Eigen::Map<const Vector>(wsr.data(), nseg_total * np);
const Vector wsr_old = Eigen::Map<const Vector>(&well_state.segPhaseRates()[0], nseg_total * np);
const Vector sr = wsr_old - dwsr;
std::copy(&sr[0], &sr[0] + sr.size(), well_state.segPhaseRates().begin());
// segment pressure updates
const Vector segp_old = Eigen::Map<const Vector>(&well_state.segPress()[0], nseg_total, 1);
// TODO: applying the pressure change limiter to all the segments, not sure if it is the correct thing to do
const Vector dsegp_limited = sign(dsegp) * dsegp.abs().min(segp_old.abs() * dpmaxrel);
const Vector segp = segp_old - dsegp_limited;
std::copy(&segp[0], &segp[0] + segp.size(), well_state.segPress().begin());
// update the well rates and bhps, which are not anymore primary vabriables.
// they are updated directly from the updated segment phase rates and segment pressures.
// Bhp update.
Vector bhp = Vector::Zero(nw);
Vector wr = Vector::Zero(nw * np);
// it is better to use subset
int start_segment = 0;
for (int w = 0; w < nw; ++w) {
bhp[w] = well_state.segPress()[start_segment];
// insert can be faster
for (int p = 0; p < np; ++p) {
wr[p + np * w] = well_state.segPhaseRates()[p + np * start_segment];
}
const int nseg = msWells()[w]->numberOfSegments();
start_segment += nseg;
}
assert(start_segment == nseg_total);
std::copy(&bhp[0], &bhp[0] + bhp.size(), well_state.bhp().begin());
std::copy(&wr[0], &wr[0] + wr.size(), well_state.wellRates().begin());
// TODO: handling the THP control related.
}
}
template <class SolutionState>
void
MultisegmentWells::
computeWellFlux(const SolutionState& state,
const std::vector<ADB>& mob_perfcells,
const std::vector<ADB>& b_perfcells,
Vector& aliveWells,
std::vector<ADB>& cq_s) const
{
if (msWells().size() == 0) return;
const int np = numPhases();
const int nw = msWells().size();
aliveWells = Vector::Constant(nw, 1.0);
const int nseg = nseg_total_;
const int nperf = nperf_total_;
const Opm::PhaseUsage& pu = fluid_->phaseUsage();
cq_s.resize(np, ADB::null());
{
const Vector& Tw = wellOps().conn_trans_factors;
const std::vector<int>& well_cells = wellOps().well_cells;
// determining in-flow (towards well-bore) or out-flow (towards reservoir)
// for mutli-segmented wells and non-segmented wells, the calculation of the drawdown are different.
const ADB& p_perfcells = subset(state.pressure, well_cells);
const ADB& rs_perfcells = subset(state.rs, well_cells);
const ADB& rv_perfcells = subset(state.rv, well_cells);
const ADB& seg_pressures = state.segp;
const ADB seg_pressures_perf = wellOps().s2p * seg_pressures;
// Create selector for perforations of multi-segment vs. regular wells.
Vector is_multisegment_well(nw);
for (int w = 0; w < nw; ++w) {
is_multisegment_well[w] = double(msWells()[w]->isMultiSegmented());
}
// Take one flag per well and expand to one flag per perforation.
Vector is_multisegment_perf = wellOps().w2p * is_multisegment_well.matrix();
Selector<double> msperf_selector(is_multisegment_perf, Selector<double>::NotEqualZero);
// Compute drawdown.
ADB h_nc = msperf_selector.select(well_segment_perforation_pressure_diffs_,
ADB::constant(well_perforation_pressure_diffs_));
const Vector h_cj = msperf_selector.select(well_perforation_cell_pressure_diffs_, Vector::Zero(nperf));
// Special handling for when we are called from solveWellEq().
// TODO: restructure to eliminate need for special treatmemt.
if ((h_nc.numBlocks() != 0) && (h_nc.numBlocks() != seg_pressures_perf.numBlocks())) {
assert(seg_pressures_perf.numBlocks() == 2);
assert(h_nc.numBlocks() > 2);
h_nc = wellhelpers::onlyWellDerivs(h_nc);
assert(h_nc.numBlocks() == 2);
}
ADB drawdown = (p_perfcells + h_cj - seg_pressures_perf - h_nc);
// selects injection perforations
Vector selectInjectingPerforations = Vector::Zero(nperf);
// selects producing perforations
Vector selectProducingPerforations = Vector::Zero(nperf);
for (int c = 0; c < nperf; ++c){
if (drawdown.value()[c] < 0)
selectInjectingPerforations[c] = 1;
else
selectProducingPerforations[c] = 1;
}
// handling flow into wellbore
// maybe there are something to do there make the procedure easier.
std::vector<ADB> cq_ps(np, ADB::null());
for (int phase = 0; phase < np; ++phase) {
const ADB cq_p = -(selectProducingPerforations * Tw) * (mob_perfcells[phase] * drawdown);
cq_ps[phase] = b_perfcells[phase] * cq_p;
}
if ((*active_)[Oil] && (*active_)[Gas]) {
const int oilpos = pu.phase_pos[Oil];
const int gaspos = pu.phase_pos[Gas];
const ADB cq_psOil = cq_ps[oilpos];
const ADB cq_psGas = cq_ps[gaspos];
cq_ps[gaspos] += rs_perfcells * cq_psOil;
cq_ps[oilpos] += rv_perfcells * cq_psGas;
}
// hadling flow out from wellbore
ADB total_mob = mob_perfcells[0];
for (int phase = 1; phase < np; ++phase) {
total_mob += mob_perfcells[phase];
}
// injection perforations total volume rates
const ADB cqt_i = -(selectInjectingPerforations * Tw) * (total_mob * drawdown);
// compute wellbore mixture for injecting perforations
// The wellbore mixture depends on the inflow from the reservoir
// and the well injection rates.
// TODO: should this based on the segments?
// TODO: for the usual wells, the well rates are the sum of the perforations.
// TODO: for multi-segmented wells, the segment rates are not the sum of the perforations.
// TODO: two options here
// TODO: 1. for each segment, only the inflow from the perforations related to this segment are considered.
// TODO: 2. for each segment, the inflow from the perforrations related to this segment and also all the inflow
// TODO: from the upstreaming sgments and their perforations need to be considered.
// TODO: This way can be the more consistent way, while let us begin with the first option. The second option
// TODO: involves one operations that are not valid now. (i.e. how to transverse from the leaves to the root,
// TODO: although we can begin from the brutal force way)
// TODO: stop using msWells() here.
std::vector<ADB> wbq(np, ADB::null());
ADB wbqt = ADB::constant(Vector::Zero(nseg));
const DataBlock compi = Eigen::Map<const DataBlock>(wells().comp_frac, nw, np);
for (int phase = 0; phase < np; ++phase) {
const ADB& q_ps = wellOps().p2s * cq_ps[phase];
const ADB& q_s = subset(state.segqs, Span(nseg, 1, phase * nseg));
Selector<double> injectingPhase_selector(q_s.value(), Selector<double>::GreaterZero);
const int pos = pu.phase_pos[phase];
// this is per segment
wbq[phase] = (wellOps().w2s * ADB::constant(compi.col(pos)) * injectingPhase_selector.select(q_s, ADB::constant(Vector::Zero(nseg)))) - q_ps;
// TODO: it should be a single value for this certain well.
// TODO: it need to be changed later to handle things more consistently
// or there should be an earsier way to decide if the well is dead.
wbqt += wbq[phase];
}
// Set aliveWells.
// the first value of the wbqt is the one to decide if the well is dead
// or there should be some dead segments?
{
int topseg = 0;
for (int w = 0; w < nw; ++w) {
if (wbqt.value()[topseg] == 0.0) { // yes we really mean == here, no fuzzyness
aliveWells[w] = 0.0;
}
topseg += msWells()[w]->numberOfSegments();
}
}
// compute wellbore mixture at standard conditions.
// before, the determination of alive wells is based on wells.
// now, will there be any dead segment? I think no.
// TODO: it is not clear if the cmix_s should be based on segment or the well
std::vector<ADB> cmix_s(np, ADB::null());
Selector<double> aliveWells_selector(aliveWells, Selector<double>::NotEqualZero);
for (int phase = 0; phase < np; ++phase) {
const int pos = pu.phase_pos[phase];
const ADB phase_fraction = wellOps().topseg2w * (wbq[phase] / wbqt);
cmix_s[phase] = wellOps().w2p * aliveWells_selector.select(phase_fraction, ADB::constant(compi.col(pos)));
}
// compute volume ration between connection at standard conditions
ADB volumeRatio = ADB::constant(Vector::Zero(nperf));
const ADB d = Vector::Constant(nperf,1.0) - rv_perfcells * rs_perfcells;
for (int phase = 0; phase < np; ++phase) {
ADB tmp = cmix_s[phase];
if (phase == Oil && (*active_)[Gas]) {
const int gaspos = pu.phase_pos[Gas];
tmp = (tmp - rv_perfcells * cmix_s[gaspos]) / d;
}
if (phase == Gas && (*active_)[Oil]) {
const int oilpos = pu.phase_pos[Oil];
tmp = (tmp - rs_perfcells * cmix_s[oilpos]) / d;
}
volumeRatio += tmp / b_perfcells[phase];
}
// injecting connections total volumerates at standard conditions
ADB cqt_is = cqt_i/volumeRatio;
// connection phase volumerates at standard conditions
for (int phase = 0; phase < np; ++phase) {
cq_s[phase] = cq_ps[phase] + cmix_s[phase]*cqt_is;
}
}
}
template <class SolutionState, class WellState>
void
MultisegmentWells::
updatePerfPhaseRatesAndPressures(const std::vector<ADB>& cq_s,
const SolutionState& state,
WellState& xw) const
{
if ( !localWellsActive() ) {
return;
}
// Update the perforation phase rates (used to calculate the pressure drop in the wellbore).
const int np = numPhases();
const int nw = numWells();
Vector cq = superset(cq_s[0].value(), Span(nperf_total_, np, 0), nperf_total_ * np);
for (int phase = 1; phase < np; ++phase) {
cq += superset(cq_s[phase].value(), Span(nperf_total_, np, phase), nperf_total_ * np);
}
xw.perfPhaseRates().assign(cq.data(), cq.data() + nperf_total_ * np);
// Update the perforation pressures for usual wells first to recover the resutls
// without mutlti segment wells. For segment wells, it has not been decided if
// we need th concept of preforation pressures
xw.perfPress().resize(nperf_total_, -1.e100);
const Vector& cdp = well_perforation_pressure_diffs_;
int start_segment = 0;
int start_perforation = 0;
for (int i = 0; i < nw; ++i) {
WellMultiSegmentConstPtr well = wells_multisegment_[i];
const int nperf = well->numberOfPerforations();
const int nseg = well->numberOfSegments();
if (well->isMultiSegmented()) {
start_segment += nseg;
start_perforation += nperf;
continue;
}
const Vector cdp_well = subset(cdp, Span(nperf, 1, start_perforation));
const ADB segp = subset(state.segp, Span(nseg, 1, start_segment));
const Vector perfpressure = (well->wellOps().s2p * segp.value().matrix()).array() + cdp_well;
std::copy(perfpressure.data(), perfpressure.data() + nperf, &xw.perfPress()[start_perforation]);
start_segment += nseg;
start_perforation += nperf;
}
assert(start_segment == nseg_total_);
assert(start_perforation == nperf_total_);
}
template <class SolutionState>
void
MultisegmentWells::
computeSegmentFluidProperties(const SolutionState& state)
{
const int np = numPhases();
const int nw = msWells().size();
const int nseg_total = nseg_total_;
if ( !wellOps().has_multisegment_wells ){
// not sure if this is needed actually
// TODO: to check later if this is really necessary.
well_segment_densities_ = ADB::constant(Vector::Zero(nseg_total));
segment_mass_flow_rates_ = ADB::constant(Vector::Zero(nseg_total));
segment_viscosities_ = ADB::constant(Vector::Zero(nseg_total));
for (int phase = 0; phase < np; ++phase) {
segment_comp_surf_volume_current_[phase] = ADB::constant(Vector::Zero(nseg_total));
segmentCompSurfVolumeInitial()[phase] = Vector::Zero(nseg_total);
}
return;
}
// although we will calculate segment density for non-segmented wells at the same time,
// while under most of the cases, they will not be used,
// since for most of the cases, the density calculation for non-segment wells are
// set to be 'SEG' way, which is not a option for multi-segment wells.
// When the density calcuation for non-segmented wells are set to 'AVG', then
// the density calculation of the mixtures can be the same, while it remains to be verified.
// The grid cells associated with segments.
// TODO: shoud be computed once and stored in WellState or global Wells structure or class.
std::vector<int> segment_cells;
segment_cells.reserve(nseg_total);
for (int w = 0; w < nw; ++w) {
const std::vector<int>& segment_cells_well = msWells()[w]->segmentCells();
segment_cells.insert(segment_cells.end(), segment_cells_well.begin(), segment_cells_well.end());
}
assert(int(segment_cells.size()) == nseg_total);
const ADB segment_temp = subset(state.temperature, segment_cells);
// using the segment pressure or the average pressure
// using the segment pressure first
const ADB& segment_press = state.segp;
// Compute PVT properties for segments.
std::vector<PhasePresence> segment_cond(nseg_total);
for (int s = 0; s < nseg_total; ++s) {
segment_cond[s] = (*phase_condition_)[segment_cells[s]];
}
std::vector<ADB> b_seg(np, ADB::null());
// Viscosities for different phases
std::vector<ADB> mu_seg(np, ADB::null());
ADB rsmax_seg = ADB::null();
ADB rvmax_seg = ADB::null();
const PhaseUsage& pu = fluid_->phaseUsage();
if (pu.phase_used[Water]) {
b_seg[pu.phase_pos[Water]] = fluid_->bWat(segment_press, segment_temp, segment_cells);
mu_seg[pu.phase_pos[Water]] = fluid_->muWat(segment_press, segment_temp, segment_cells);
}
assert((*active_)[Oil]);
const ADB segment_so = subset(state.saturation[pu.phase_pos[Oil]], segment_cells);
if (pu.phase_used[Oil]) {
const ADB segment_rs = subset(state.rs, segment_cells);
b_seg[pu.phase_pos[Oil]] = fluid_->bOil(segment_press, segment_temp, segment_rs,
segment_cond, segment_cells);
// rsmax_seg = fluidRsSat(segment_press, segment_so, segment_cells);
rsmax_seg = fluid_->rsSat(segment_press, segment_so, segment_cells);
mu_seg[pu.phase_pos[Oil]] = fluid_->muOil(segment_press, segment_temp, segment_rs,
segment_cond, segment_cells);
}
assert((*active_)[Gas]);
if (pu.phase_used[Gas]) {
const ADB segment_rv = subset(state.rv, segment_cells);
b_seg[pu.phase_pos[Gas]] = fluid_->bGas(segment_press, segment_temp, segment_rv,
segment_cond, segment_cells);
// rvmax_seg = fluidRvSat(segment_press, segment_so, segment_cells);
rvmax_seg = fluid_->rvSat(segment_press, segment_so, segment_cells);
mu_seg[pu.phase_pos[Gas]] = fluid_->muGas(segment_press, segment_temp, segment_rv,
segment_cond, segment_cells);
}
// Extract segment flow by phase (segqs) and compute total surface rate.
ADB tot_surface_rate = ADB::constant(Vector::Zero(nseg_total));
std::vector<ADB> segqs(np, ADB::null());
for (int phase = 0; phase < np; ++phase) {
segqs[phase] = subset(state.segqs, Span(nseg_total, 1, phase * nseg_total));
tot_surface_rate += segqs[phase];
}
// TODO: later this will be implmented as a global mapping
std::vector<std::vector<double>> comp_frac(np, std::vector<double>(nseg_total, 0.0));
int start_segment = 0;
for (int w = 0; w < nw; ++w) {
WellMultiSegmentConstPtr well = msWells()[w];
const int nseg = well->numberOfSegments();
const std::vector<double>& comp_frac_well = well->compFrac();
for (int phase = 0; phase < np; ++phase) {
for (int s = 0; s < nseg; ++s) {
comp_frac[phase][s + start_segment] = comp_frac_well[phase];
}
}
start_segment += nseg;
}
assert(start_segment == nseg_total);
// Compute mix.
// 'mix' contains the component fractions under surface conditions.
std::vector<ADB> mix(np, ADB::null());
for (int phase = 0; phase < np; ++phase) {
// initialize to be the compFrac for each well,
// then update only the one with non-zero total volume rate
mix[phase] = ADB::constant(Eigen::Map<Vector>(comp_frac[phase].data(), nseg_total));
}
// There should be a better way to do this.
Selector<double> non_zero_tot_rate(tot_surface_rate.value(), Selector<double>::NotEqualZero);
for (int phase = 0; phase < np; ++phase) {
mix[phase] = non_zero_tot_rate.select(segqs[phase] / tot_surface_rate, mix[phase]);
}
// Calculate rs and rv.
ADB rs = ADB::constant(Vector::Zero(nseg_total));
ADB rv = rs;
const int gaspos = pu.phase_pos[Gas];
const int oilpos = pu.phase_pos[Oil];
Selector<double> non_zero_mix_oilpos(mix[oilpos].value(), Selector<double>::GreaterZero);
Selector<double> non_zero_mix_gaspos(mix[gaspos].value(), Selector<double>::GreaterZero);
// What is the better way to do this?
// big values should not be necessary
ADB big_values = ADB::constant(Vector::Constant(nseg_total, 1.e100));
ADB mix_gas_oil = non_zero_mix_oilpos.select(mix[gaspos] / mix[oilpos], big_values);
ADB mix_oil_gas = non_zero_mix_gaspos.select(mix[oilpos] / mix[gaspos], big_values);
if ((*active_)[Oil]) {
Vector selectorUnderRsmax = Vector::Zero(nseg_total);
Vector selectorAboveRsmax = Vector::Zero(nseg_total);
for (int s = 0; s < nseg_total; ++s) {
if (mix_gas_oil.value()[s] > rsmax_seg.value()[s]) {
selectorAboveRsmax[s] = 1.0;
} else {
selectorUnderRsmax[s] = 1.0;
}
}
rs = non_zero_mix_oilpos.select(selectorAboveRsmax * rsmax_seg + selectorUnderRsmax * mix_gas_oil, rs);
}
if ((*active_)[Gas]) {
Vector selectorUnderRvmax = Vector::Zero(nseg_total);
Vector selectorAboveRvmax = Vector::Zero(nseg_total);
for (int s = 0; s < nseg_total; ++s) {
if (mix_oil_gas.value()[s] > rvmax_seg.value()[s]) {
selectorAboveRvmax[s] = 1.0;
} else {
selectorUnderRvmax[s] = 1.0;
}
}
rv = non_zero_mix_gaspos.select(selectorAboveRvmax * rvmax_seg + selectorUnderRvmax * mix_oil_gas, rv);
}
// Calculate the phase fraction under reservoir conditions.
std::vector<ADB> x(np, ADB::null());
for (int phase = 0; phase < np; ++phase) {
x[phase] = mix[phase];
}
if ((*active_)[Gas] && (*active_)[Oil]) {
x[gaspos] = (mix[gaspos] - mix[oilpos] * rs) / (Vector::Ones(nseg_total) - rs * rv);
x[oilpos] = (mix[oilpos] - mix[gaspos] * rv) / (Vector::Ones(nseg_total) - rs * rv);
}
// Compute total reservoir volume to surface volume ratio.
ADB volrat = ADB::constant(Vector::Zero(nseg_total));
for (int phase = 0; phase < np; ++phase) {
volrat += x[phase] / b_seg[phase];
}
// Compute segment densities.
ADB dens = ADB::constant(Vector::Zero(nseg_total));
for (int phase = 0; phase < np; ++phase) {
const Vector surface_density = fluid_->surfaceDensity(phase, segment_cells);
dens += surface_density * mix[phase];
}
well_segment_densities_ = dens / volrat;
// Calculating the surface volume of each component in the segment
assert(np == int(segment_comp_surf_volume_current_.size()));
const ADB segment_surface_volume = segvdt_ / volrat;
for (int phase = 0; phase < np; ++phase) {
segment_comp_surf_volume_current_[phase] = segment_surface_volume * mix[phase];
}
// Mass flow rate of the segments
segment_mass_flow_rates_ = ADB::constant(Vector::Zero(nseg_total));
for (int phase = 0; phase < np; ++phase) {
// TODO: how to remove one repeated surfaceDensity()
const Vector surface_density = fluid_->surfaceDensity(phase, segment_cells);
segment_mass_flow_rates_ += surface_density * segqs[phase];
}
// Viscosity of the fluid mixture in the segments
segment_viscosities_ = ADB::constant(Vector::Zero(nseg_total));
for (int phase = 0; phase < np; ++phase) {
segment_viscosities_ += x[phase] * mu_seg[phase];
}
}
template <class SolutionState>
void
MultisegmentWells::
addWellFluxEq(const std::vector<ADB>& cq_s,
const SolutionState& state,
LinearisedBlackoilResidual& residual)
{
if ( !localWellsActive() ) {
return;
}
// the well flux equations are for each segment and each phase.
// /delta m_p_n / dt - /sigma Q_pi - /sigma q_pj + Q_pn = 0
// 1. It is the gain of the amount of the component p in the segment n during the
// current time step under stock-tank conditions.
// It is used to handle the volume storage effects of the wellbore.
// We need the information from the previous step and the crrent time step.
// 2. for the second term, it is flow into the segment from the inlet segments,
// which are unknown and treated implictly.
// 3. for the third term, it is the inflow through the perforations.
// 4. for the last term, it is the outlet rates and also the segment rates,
// which are the primary variable.
const int np = numPhases();
const int nseg_total = nseg_total_;
ADB segqs = state.segqs;
std::vector<ADB> segment_volume_change_dt(np, ADB::null());
for (int phase = 0; phase < np; ++phase) {
if ( wellOps().has_multisegment_wells ) {
// Gain of the surface volume of each component in the segment by dt
segment_volume_change_dt[phase] = segment_comp_surf_volume_current_[phase] -
segmentCompSurfVolumeInitial()[phase];
// Special handling for when we are called from solveWellEq().
// TODO: restructure to eliminate need for special treatmemt.
if (segment_volume_change_dt[phase].numBlocks() != segqs.numBlocks()) {
assert(segment_volume_change_dt[phase].numBlocks() > 2);
assert(segqs.numBlocks() == 2);
segment_volume_change_dt[phase] = wellhelpers::onlyWellDerivs(segment_volume_change_dt[phase]);
assert(segment_volume_change_dt[phase].numBlocks() == 2);
}
const ADB cq_s_seg = wellOps().p2s * cq_s[phase];
const ADB segqs_phase = subset(segqs, Span(nseg_total, 1, phase * nseg_total));
segqs -= superset(cq_s_seg + wellOps().s2s_inlets * segqs_phase + segment_volume_change_dt[phase],
Span(nseg_total, 1, phase * nseg_total), np * nseg_total);
} else {
segqs -= superset(wellOps().p2s * cq_s[phase], Span(nseg_total, 1, phase * nseg_total), np * nseg_total);
}
}
residual.well_flux_eq = segqs;
}
template <class SolutionState, class WellState>
void
MultisegmentWells::
addWellControlEq(const SolutionState& state,
const WellState& xw,
const Vector& aliveWells,
LinearisedBlackoilResidual& residual)
{
// the name of the function is a a little misleading.
// Basically it is the function for the pressure equation.
// And also, it work as the control equation when it is the segment
if( msWells().empty() ) return;
const int np = numPhases();
const int nw = msWells().size();
const int nseg_total = nseg_total_;
ADB aqua = ADB::constant(Vector::Zero(nseg_total));
ADB liquid = ADB::constant(Vector::Zero(nseg_total));
ADB vapour = ADB::constant(Vector::Zero(nseg_total));
if ((*active_)[Water]) {
aqua += subset(state.segqs, Span(nseg_total, 1, BlackoilPhases::Aqua * nseg_total));
}
if ((*active_)[Oil]) {
liquid += subset(state.segqs, Span(nseg_total, 1, BlackoilPhases::Liquid * nseg_total));
}
if ((*active_)[Gas]) {
vapour += subset(state.segqs, Span(nseg_total, 1, BlackoilPhases::Vapour * nseg_total));
}
// THP control is not implemented for the moment.
// Hydrostatic correction variables
Vector rho_v = Vector::Zero(nw);
Vector vfp_ref_depth_v = Vector::Zero(nw);
// Target vars
Vector bhp_targets = Vector::Zero(nw);
Vector rate_targets = Vector::Zero(nw);
Eigen::SparseMatrix<double> rate_distr(nw, np*nw);
// Selection variables
// well selectors
std::vector<int> bhp_well_elems;
std::vector<int> rate_well_elems;
// segment selectors
std::vector<int> bhp_top_elems;
std::vector<int> rate_top_elems;
std::vector<int> rate_top_phase_elems;
std::vector<int> others_elems;
//Run through all wells to calculate BHP/RATE targets
//and gather info about current control
int start_segment = 0;
for (int w = 0; w < nw; ++w) {
const struct WellControls* wc = msWells()[w]->wellControls();
// The current control in the well state overrides
// the current control set in the Wells struct, which
// is instead treated as a default.
const int current = xw.currentControls()[w];
const int nseg = msWells()[w]->numberOfSegments();
switch (well_controls_iget_type(wc, current)) {
case BHP:
{
bhp_well_elems.push_back(w);
bhp_top_elems.push_back(start_segment);
bhp_targets(w) = well_controls_iget_target(wc, current);
rate_targets(w) = -1e100;
for (int p = 0; p < np; ++p) {
rate_top_phase_elems.push_back(np * start_segment + p);
}
}
break;
case THP:
{
OPM_THROW(std::runtime_error, "THP control is not implemented for multi-sgement wells yet!!");
}
break;
case RESERVOIR_RATE: // Intentional fall-through
case SURFACE_RATE:
{
rate_well_elems.push_back(w);
rate_top_elems.push_back(start_segment);
for (int p = 0; p < np; ++p) {
rate_top_phase_elems.push_back(np * start_segment + p);
}
// RESERVOIR and SURFACE rates look the same, from a
// high-level point of view, in the system of
// simultaneous linear equations.
const double* const distr =
well_controls_iget_distr(wc, current);
for (int p = 0; p < np; ++p) {
rate_distr.insert(w, p*nw + w) = distr[p];
}
bhp_targets(w) = -1.0e100;
rate_targets(w) = well_controls_iget_target(wc, current);
}
break;
}
for (int i = 1; i < nseg; ++i) {
others_elems.push_back(i + start_segment);
}
start_segment += nseg;
}
// for each segment: 1, if the segment is the top segment, then control equation
// 2, if the segment is not the top segment, then the pressure equation
const ADB bhp_residual = subset(state.segp, bhp_top_elems) - subset(bhp_targets, bhp_well_elems);
const ADB rate_residual = subset(rate_distr * subset(state.segqs, rate_top_phase_elems) - rate_targets, rate_well_elems);
ADB others_residual = ADB::constant(Vector::Zero(nseg_total));
if ( wellOps().has_multisegment_wells ) {
// Special handling for when we are called from solveWellEq().
// TODO: restructure to eliminate need for special treatmemt.
ADB wspd = (state.segp.numBlocks() == 2)
? wellhelpers::onlyWellDerivs(well_segment_pressures_delta_)
: well_segment_pressures_delta_;
others_residual = wellOps().eliminate_topseg * (state.segp - wellOps().s2s_outlet * state.segp + wspd);
} else {
others_residual = wellOps().eliminate_topseg * (state.segp - wellOps().s2s_outlet * state.segp);
}
// all the control equations
// TODO: can be optimized better
ADB well_eq_topsegment = subset(superset(bhp_residual, bhp_top_elems, nseg_total) +
superset(rate_residual, rate_top_elems, nseg_total), top_well_segments_);
// For wells that are dead (not flowing), and therefore not communicating
// with the reservoir, we set the equation to be equal to the well's total
// flow. This will be a solution only if the target rate is also zero.
Eigen::SparseMatrix<double> rate_summer(nw, np*nw);
for (int w = 0; w < nw; ++w) {
for (int phase = 0; phase < np; ++phase) {
rate_summer.insert(w, phase*nw + w) = 1.0;
}
}
Selector<double> alive_selector(aliveWells, Selector<double>::NotEqualZero);
// TODO: Here only handles the wells, or the top segments
// should we also handle some non-alive non-top segments?
// should we introduce the cocept of non-alive segments?
// At the moment, we only handle the control equations
well_eq_topsegment = alive_selector.select(well_eq_topsegment, rate_summer * subset(state.segqs, rate_top_phase_elems));
/* residual_.well_eq = superset(bhp_residual, bhp_top_elems, nseg_total) +
superset(rate_residual, rate_top_elems, nseg_total) +
superset(others_residual, others_elems, nseg_total); */
residual.well_eq = superset(well_eq_topsegment, top_well_segments_, nseg_total) +
others_residual;
}
template <class WellState>
void
MultisegmentWells::
updateWellControls(WellState& xw) const
{
wellhelpers::WellSwitchingLogger logger;
if( msWells().empty() ) return ;
// Find, for each well, if any constraints are broken. If so,
// switch control to first broken constraint.
const int np = numPhases();
const int nw = msWells().size();
for (int w = 0; w < nw; ++w) {
const WellControls* wc = msWells()[w]->wellControls();
// The current control in the well state overrides
// the current control set in the Wells struct, which
// is instead treated as a default.
int current = xw.currentControls()[w];
// Loop over all controls except the current one, and also
// skip any RESERVOIR_RATE controls, since we cannot
// handle those.
const int nwc = well_controls_get_num(wc);
int ctrl_index = 0;
for (; ctrl_index < nwc; ++ctrl_index) {
if (ctrl_index == current) {
// This is the currently used control, so it is
// used as an equation. So this is not used as an
// inequality constraint, and therefore skipped.
continue;
}
if (wellhelpers::constraintBroken(
xw.bhp(), xw.thp(), xw.wellRates(),
w, np, msWells()[w]->wellType(), wc, ctrl_index)) {
// ctrl_index will be the index of the broken constraint after the loop.
break;
}
}
if (ctrl_index != nwc) {
// Constraint number ctrl_index was broken, switch to it.
// Each well is only active on one process. Therefore we always print the sitch info.
logger.wellSwitched(msWells()[w]->name(),
well_controls_iget_type(wc, current),
well_controls_iget_type(wc, ctrl_index));
xw.currentControls()[w] = ctrl_index;
current = xw.currentControls()[w];
}
// Get gravity for THP hydrostatic corrrection
// const double gravity = detail::getGravity(geo_.gravity(), UgGridHelpers::dimensions(grid_));
// Updating well state and primary variables.
// Target values are used as initial conditions for BHP, THP, and SURFACE_RATE
const double target = well_controls_iget_target(wc, current);
const double* distr = well_controls_iget_distr(wc, current);
switch (well_controls_iget_type(wc, current)) {
case BHP:
xw.bhp()[w] = target;
xw.segPress()[top_well_segments_[w]] = target;
break;
case THP: {
OPM_THROW(std::runtime_error, "THP control is not implemented for multi-sgement wells yet!!");
}
case RESERVOIR_RATE:
// No direct change to any observable quantity at
// surface condition. In this case, use existing
// flow rates as initial conditions as reservoir
// rate acts only in aggregate.
break;
case SURFACE_RATE:
for (int phase = 0; phase < np; ++phase) {
if (distr[phase] > 0.0) {
xw.wellRates()[np * w + phase] = target * distr[phase];
// TODO: consider changing all (not just top) segment rates
// to make them consistent, it could possibly improve convergence.
xw.segPhaseRates()[np * xw.topSegmentLoc()[w] + phase] = target * distr[phase];
}
}
break;
}
if (wellCollection()->groupControlActive()) {
// get the well node in the well collection
WellNode& well_node = well_collection_->findWellNode(std::string(wells().name[w]));
// update whehter the well is under group control or individual control
if (well_node.groupControlIndex() >= 0 && current == well_node.groupControlIndex()) {
// under group control
well_node.setIndividualControl(false);
} else {
// individual control
well_node.setIndividualControl(true);
}
}
}
}
// TODO: This is just a preliminary version, remains to be improved later when we decide a better way
// TODO: to intergrate the usual wells and multi-segment wells.
template <class SolutionState, class WellState>
void
MultisegmentWells::
computeWellConnectionPressures(const SolutionState& state,
const WellState& xw,
const std::vector<ADB>& kr_adb,
const std::vector<ADB>& fluid_density)
{
if( ! wellsActive() ) return ;
using namespace Opm::AutoDiffGrid;
// 1. Compute properties required by computeConnectionPressureDelta().
// Note that some of the complexity of this part is due to the function
// taking std::vector<double> arguments, and not Eigen objects.
const int nperf_total = nperf_total_;
const int nw = numWells();
const std::vector<int>& well_cells = wellOps().well_cells;
well_perforation_densities_ = Vector::Zero(nperf_total);
const Vector perf_press = Eigen::Map<const Vector>(xw.perfPress().data(), nperf_total);
Vector avg_press = perf_press * 0.0;
// for the non-segmented/regular wells, calculated the average pressures.
// If it is the top perforation, then average with the bhp().
// If it is not the top perforation, then average with the perforation above it().
int start_segment = 0;
for (int w = 0; w < nw; ++w) {
const int nseg = wells_multisegment_[w]->numberOfSegments();
if (wells_multisegment_[w]->isMultiSegmented()) {
// maybe we should give some reasonable values to prevent the following calculations fail
start_segment += nseg;
continue;
}
std::string well_name(wells_multisegment_[w]->name());
typedef typename WellState::SegmentedWellMapType::const_iterator const_iterator;
const_iterator it_well = xw.segmentedWellMap().find(well_name);
assert(it_well != xw.segmentedWellMap().end());
const int start_perforation = (*it_well).second.start_perforation;
const int end_perforation = start_perforation + (*it_well).second.number_of_perforations;
for (int perf = start_perforation; perf < end_perforation; ++perf) {
const double p_above = perf == start_perforation ? state.segp.value()[start_segment] : perf_press[perf - 1];
const double p_avg = (perf_press[perf] + p_above)/2;
avg_press[perf] = p_avg;
}
start_segment += nseg;
}
assert(start_segment == xw.numSegments());
// Use cell values for the temperature as the wells don't knows its temperature yet.
const ADB perf_temp = subset(state.temperature, well_cells);
// Compute b, rsmax, rvmax values for perforations.
// Evaluate the properties using average well block pressures
// and cell values for rs, rv, phase condition and temperature.
const ADB avg_press_ad = ADB::constant(avg_press);
std::vector<PhasePresence> perf_cond(nperf_total);
for (int perf = 0; perf < nperf_total; ++perf) {
perf_cond[perf] = (*phase_condition_)[well_cells[perf]];
}
const PhaseUsage& pu = fluid_->phaseUsage();
DataBlock b(nperf_total, pu.num_phases);
std::vector<double> rsmax_perf(nperf_total, 0.0);
std::vector<double> rvmax_perf(nperf_total, 0.0);
if (pu.phase_used[BlackoilPhases::Aqua]) {
const Vector bw = fluid_->bWat(avg_press_ad, perf_temp, well_cells).value();
b.col(pu.phase_pos[BlackoilPhases::Aqua]) = bw;
}
assert((*active_)[Oil]);
const Vector perf_so = subset(state.saturation[pu.phase_pos[Oil]].value(), well_cells);
if (pu.phase_used[BlackoilPhases::Liquid]) {
const ADB perf_rs = subset(state.rs, well_cells);
const Vector bo = fluid_->bOil(avg_press_ad, perf_temp, perf_rs, perf_cond, well_cells).value();
b.col(pu.phase_pos[BlackoilPhases::Liquid]) = bo;
const Vector rssat = fluid_->rsSat(ADB::constant(avg_press), ADB::constant(perf_so), well_cells).value();
rsmax_perf.assign(rssat.data(), rssat.data() + nperf_total);
}
if (pu.phase_used[BlackoilPhases::Vapour]) {
const ADB perf_rv = subset(state.rv, well_cells);
const Vector bg = fluid_->bGas(avg_press_ad, perf_temp, perf_rv, perf_cond, well_cells).value();
b.col(pu.phase_pos[BlackoilPhases::Vapour]) = bg;
const Vector rvsat = fluid_->rvSat(ADB::constant(avg_press), ADB::constant(perf_so), well_cells).value();
rvmax_perf.assign(rvsat.data(), rvsat.data() + nperf_total);
}
// b is row major, so can just copy data.
std::vector<double> b_perf(b.data(), b.data() + nperf_total * pu.num_phases);
const Vector& perfcelldepth = perf_cell_depth_;
std::vector<double> perf_cell_depth(perfcelldepth.data(), perfcelldepth.data() + nperf_total);
// Surface density.
// The compute density segment wants the surface densities as
// an np * number of wells cells array
Vector rho = superset(fluid_->surfaceDensity(0 , well_cells), Span(nperf_total, pu.num_phases, 0), nperf_total * pu.num_phases);
for (int phase = 1; phase < pu.num_phases; ++phase) {
rho += superset(fluid_->surfaceDensity(phase , well_cells), Span(nperf_total, pu.num_phases, phase), nperf_total * pu.num_phases);
}
std::vector<double> surf_dens_perf(rho.data(), rho.data() + nperf_total * pu.num_phases);
// 2. Compute densities
std::vector<double> cd =
WellDensitySegmented::computeConnectionDensities(
wells(), fluid_->phaseUsage(), xw.perfPhaseRates(),
b_perf, rsmax_perf, rvmax_perf, surf_dens_perf);
// 3. Compute pressure deltas
std::vector<double> cdp =
WellDensitySegmented::computeConnectionPressureDelta(
wells(), perf_cell_depth, cd, gravity_);
// 4. Store the results
well_perforation_densities_ = Eigen::Map<const Vector>(cd.data(), nperf_total); // This one is not useful for segmented wells at all
well_perforation_pressure_diffs_ = Eigen::Map<const Vector>(cdp.data(), nperf_total);
if ( !wellOps().has_multisegment_wells ) {
well_perforation_cell_densities_ = Vector::Zero(nperf_total);
well_perforation_cell_pressure_diffs_ = Vector::Zero(nperf_total);
return;
}
// compute the average of the fluid densites in the well blocks.
// the average is weighted according to the fluid relative permeabilities.
// const std::vector<ADB> kr_adb = Base::computeRelPerm(state);
size_t temp_size = kr_adb.size();
std::vector<Vector> perf_kr;
for(size_t i = 0; i < temp_size; ++i) {
// const ADB kr_phase_adb = subset(kr_adb[i], well_cells);
const Vector kr_phase = (subset(kr_adb[i], well_cells)).value();
perf_kr.push_back(kr_phase);
}
// compute the averaged density for the well block
// TODO: for the non-segmented wells, they should be set to zero
// TODO: for the moment, they are still calculated, while not used later.
for (int i = 0; i < nperf_total; ++i) {
double sum_kr = 0.;
int np = perf_kr.size(); // make sure it is 3
for (int p = 0; p < np; ++p) {
sum_kr += perf_kr[p][i];
}
for (int p = 0; p < np; ++p) {
perf_kr[p][i] /= sum_kr;
}
}
Vector rho_avg_perf = Vector::Constant(nperf_total, 0.0);
// TODO: make sure the order of the density and the order of the kr are the same.
for (int phaseIdx = 0; phaseIdx < fluid_->numPhases(); ++phaseIdx) {
// const int canonicalPhaseIdx = canph_[phaseIdx];
// const ADB fluid_density = fluidDensity(canonicalPhaseIdx, rq_[phaseIdx].b, state.rs, state.rv);
const Vector rho_perf = subset(fluid_density[phaseIdx], well_cells).value();
// TODO: phaseIdx or canonicalPhaseIdx ?
rho_avg_perf += rho_perf * perf_kr[phaseIdx];
}
well_perforation_cell_densities_ = Eigen::Map<const Vector>(rho_avg_perf.data(), nperf_total);
well_perforation_cell_pressure_diffs_ = gravity_ * well_perforation_cell_densities_ * perf_cell_depth_diffs_;
}
template <class SolutionState>
void
MultisegmentWells::
variableStateExtractWellsVars(const std::vector<int>& indices,
std::vector<ADB>& vars,
SolutionState& state) const
{
// TODO: using the original Qs for the segment rates for now, to be fixed eventually.
// TODO: using the original Bhp for the segment pressures for now, to be fixed eventually.
// segment phase rates in surface volume
state.segqs = std::move(vars[indices[Qs]]);
// segment pressures
state.segp = std::move(vars[indices[Bhp]]);
// The qs and bhp are no longer primary variables, but could
// still be used in computations. They are identical to the
// pressures and flows of the top segments.
const int np = num_phases_;
const int ns = nseg_total_;
const int nw = numWells();
state.qs = ADB::constant(Vector::Zero(np * nw));
for (int phase = 0; phase < np; ++phase) {
// Extract segment fluxes for this phase (ns consecutive elements).
ADB segqs_phase = subset(state.segqs, Span(ns, 1, ns*phase));
// Extract top segment fluxes (= well fluxes)
ADB wellqs_phase = subset(segqs_phase, topWellSegments());
// Expand to full size of qs (which contains all phases) and add.
state.qs += superset(wellqs_phase, Span(nw, 1, nw * phase), nw * np);
}
state.bhp = subset(state.segp, topWellSegments());
}
template <class WellState>
void
MultisegmentWells::
variableWellStateInitials(const WellState& xw,
std::vector<Vector>& vars0) const
{
// Initial well rates
if ( wells_multisegment_.size() > 0 )
{
// Need to reshuffle well segment rates, from phase running fastest
const int nseg = xw.numSegments();
const int np = xw.numPhases();
// The transpose() below switches the ordering of the segment rates
const DataBlock segrates = Eigen::Map<const DataBlock>(& xw.segPhaseRates()[0], nseg, np).transpose();
// segment phase rates in surface volume
const Vector segqs = Eigen::Map<const Vector>(segrates.data(), nseg * np);
vars0.push_back(segqs);
// for the pressure of the segments
const Vector segp = Eigen::Map<const Vector>(& xw.segPress()[0], xw.segPress().size());
vars0.push_back(segp);
}
else
{
// push null sates for segqs and segp
vars0.push_back(Vector());
vars0.push_back(Vector());
}
}
}
#endif // OPM_MULTISEGMENTWELLS_IMPL_HEADER_INCLUDED