Parent Command
> OBSERVATION

Subcommand
>>> ELEMENT

Description
This command selects as an observation type the phase pressure or capillary pressure. This observation type refers to one or more elements. The phase name phase_name or phase number iphase, which depend on the EOS module being used, are listed in the header of the iTOUGH2 output file. They can be specified either on the command line or using subcommand >>>> PHASE. If no phase is specified, iTOUGH2 takes the pressure of the first phase which is usually the reference pressure. The pressure of a phase is calculated as the sum of the reference pressure and the corresponding capillary pressure. In a two-phase system, there is only one capillary pressure. The capillary pressure can be selected using keyword CAPILLARY. In a three-phase system (e.g., gas, NAPL, aqueous phase), there are two capillary pressures, i.e., the capillary pressure between the NAPL and the gas phase, and between the aqueous and the gas phase, which is the reference phase. The name of the wetting phase must be provided to identify the particular capillary pressure in the three-phase system.

Example
> OBSERVATION
>> PRESSURE
>>> ELEMENT: AA__1 + 56
>>>> ANNOTATION : Mean gas pressure
>>>> take AVERAGE of pressures in all 57 elements
>>>> DATA on FILE : pres.dat
>>>> VARIANCE : 1E6 Pa^2
<<<<
<<<

>> NAPL CAPILLARY PRESSURE
>>> ELEMENT: BB__1
>>>> take LOGARITHM of
>>>> ABSOLUTE Pco
>>>> DATA on FILE : Pco.dat
>>>> DEVIATION : 1.0 log-cycle
<<<<
<<<

See Also
>> DRAWDOWN