The pvt interface is extended to handle wet-gas systems:
1. rvSat is added as a function in the PVT interface
2. SinglePvtLiveGas computes the pvt values and its derivatives
3. The old rbub variable is changed to rsSat for clearity
4. The new interface is tested in test_blackoilfluid with data from
liveoil.DATA and wetgas.DATA
Commit a5a4d7b introduced density and viscosity evaluators into the
SinglePvtInterface that accepted an externally assignable condition
to distinguish saturated from unsaturated cases. As a result of a
few low-level technical problems with that approach, this commit
changes those affected interfaces to use the black-oil specific
'PhasePresence' facility of commit a033329 instead.
Update tests and callers accordingly.
Suggested by: @andlaus
Approved by: @atgeirr
Functions for volume factor and viscosity that explicitly take a boolean
variable indicating whether the fluid is saturated or not is added to
the SinglePvtInterface.
Corresponding changes are done in the dependent PVT files.
The new functionality is tested in test_blackoilfluid
Tor Harald Sandve
Bård Skaflestad
Andreas Lauser
Atgeirr Flø Rasmussen