virtual void upscale_pressure (const double* coarseSaturation,
const double* finePressure,
double* coarsePressure) {
// pressure locations we'll have to relate to
static const int FIRST_BLOCK = 0; // relative index in the column
static const double HALFWAY = 0.5; // center of the block
// incompressible means that the density is the same everywhere
// we can thus cache the phase properties outside of the loop
const double gas_dens = density ()[GAS];
const double wat_dens = density ()[WAT];
// helper object to get the index (into the pressure array) and
// the height of elements in a column
const rlw_double ts_dz (ts.number_of_cells, ts.col_cellpos, ts.dz);
const rlw_int col_cells (ts.number_of_cells, ts.col_cellpos, ts.col_cells);
// upscale each column separately. assume that something like the
// EQUIL keyword has been used in the Eclipse file and that the
// pressures are already in equilibrium. thus, we only need to
// extract the pressure at the reference point (top surface)
for (int col = 0; col < col_cells.cols (); ++col) {
// location of the brine-co2 phase contact
const double gas_sat = coarseSaturation[col * NUM_PHASES + GAS];
const Elevation& intf_lvl = intf_elev (col, gas_sat);
// what fraction of the first block from the pressure point (halfway)
// up to the top surface is of each of the phases? if the interface
// is below the first block, or if it is further down than halfway,
// then everything, otherwise the fraction (less than 0.5)
double gas_frac = (intf_lvl.block () == FIRST_BLOCK) ?
min (HALFWAY, intf_lvl.fraction ()) : HALFWAY;
// id of the upper-most block of this column. if there is no
// blocks, then the TopSurf object wouldn't generate a column.
const int block_id = col_cells[col][FIRST_BLOCK];
// height of the uppermost block (twice the distance from the top
// to the center
const double hgt = ts_dz[col][FIRST_BLOCK];
// get the pressure in the middle of this block
const double mid_pres = finePressure[block_id];
// pressure at the reference point; adjust hydrostatically for
// those phases that are on the way up from the center of the first
// block in the column.
const double ref_pres = mid_pres - gravity * hgt *
(gas_frac * gas_dens + (HALFWAY - gas_frac) * wat_dens);
// Eclipse uses non-aquous pressure (see Variable Sets in Formulation
// of the Equations in the Technical Description) as the main unknown
// in the pressure equation; there is assumed continuity at the
// contact, so the pressure at the top should always be a CO2 pressure
coarsePressure[col] = ref_pres;
}
}
virtual void downscale_pressure (const double* coarseSaturation,
const double* coarsePressure,
double* finePressure) {
// pressure locations we'll have to relate to
static const double HALFWAY = 0.5; // center of the block
// helper object to get the index (into the pressure array) and
// the height of elements in a column
const rlw_double ts_h (ts.number_of_cells, ts.col_cellpos, ts.h);
const rlw_double ts_dz (ts.number_of_cells, ts.col_cellpos, ts.dz);
const rlw_int col_cells (ts.number_of_cells, ts.col_cellpos, ts.col_cells);
// incompressible means that the density is the same everywhere
// we can thus cache the phase properties outside of the loop
const double gas_dens = density ()[GAS];
const double wat_dens = density ()[WAT];
for (int col = 0; col < col_cells.cols (); ++col) {
// location of the brine-co2 phase contact
const double gas_sat = coarseSaturation[col * NUM_PHASES + GAS];
const Elevation& intf_lvl = intf_elev (col, gas_sat);
// get the pressure difference between the phases at top of this column
const double sat[NUM_PHASES] = { gas_sat, 1-gas_sat };
double pres_diff;
capPress (1, sat, &col, &pres_diff, 0);
// get the reference phase pressure at the top; notice that the CO2
// pressure is the largest so we subtract the difference
const double gas_ref = coarsePressure[col];
const double wat_ref = gas_ref - pres_diff;
// are we going to include the block with the interface
const int incl_intf = intf_lvl.fraction () >= HALFWAY ? 1 : 0;
const int num_gas_rows = intf_lvl.block () + incl_intf;
// write all CO2 pressure blocks
for (int row = 0; row < num_gas_rows; ++row) {
// height of block center
const double hgt = ts_h[col][row] + HALFWAY * ts_dz[col][row];
// hydrostatically get the pressure for this block
const double gas_pres = gas_ref + gravity * hgt * gas_dens;
const int block = col_cells[col][row];
// (scatter) write to output array
finePressure[block] = gas_pres;
}
// then write the brine blocks, starting where we left off
for (int row = num_gas_rows; row < col_cells.size (col); ++row) {
// height of block center
const double hgt = ts_h[col][row] + HALFWAY * ts_dz[col][row];
// hydrostatically get the pressure for this block
const double wat_pres = wat_ref + gravity * hgt * wat_dens;
const int block = col_cells[col][row];
// (scatter) write to output array
finePressure[block] = wat_pres;
}
}
}