# EOS COMP¶

When in COMP mode, the EOS COMP table is available to specify EOS properties for the various components. The equation of state used is always cubic. This replaces EOS OIL and EOS GAS.

An example of the table is as follows:

EOS COMP
PREOS
GCOND
CNAME      CO2N2   C1     C2     C3     C46    C7P1   C7P2   C7P3
TCRIT K    215.2   186.6  305.4  369.9  396.2  572.5  630.2  862.6
PCRIT Bar  53.903  45.6   46.20  42.55  34.35  25.93  16.92  8.61
ZCRIT      0.283   0.224  0.285  0.281  0.274  0.260  0.260  0.260
ZMF   Frac 0.0315  0.6599 0.0869 0.0591 0.0967 0.0472 0.0153 0.0034
ACF        0.1325  0.013  0.098  0.152  0.234  0.332  0.495  0.833
MW         36.01   16.04  30.07  44.10  67.28  110.9  170.9  282.1
BIC 0.036
BIC 0.05   0
BIC 0.08   0       0
BIC 0.1002 0.09281 0       0
BIC 0.1    0       0.00385 0.00385 0
BIC 0.1    0       0.00630 0.00630 0 0
BIC 0.1    0.1392  0.00600 0.00600 0 0 0
END


The sub-keywords in EOS COMP are described below:

## PREOS¶

Specify to use the Peng-Robinson equation of state.

## SRKEOS¶

Specify to use the Soave-Redlich-Kwong equation of state.

## CNAME¶

Followed by a set of component names. If not supplied, internal names like C1, C2 will be generated.

## TCRIT¶

Component critical temperatures. Followed by unit (K is only option at present). Then Nch values, where Nch = Nc-1 is the number of non water components.

## PCRIT¶

Component critical pressures. Followed by pressure unit (e.g., Bar), then Nch values.

## ZCRIT¶

Component critical Z-factors. No unit; followed by Nch values.

## ZMF¶

Reservoir non-aqueous phase composition. Followed by unit (Frac or Percentage), then Nch values. The composition can be over-ridden on a cell by cell basis using ZMFVD.

## ACF¶

Component acentric factors. No unit; followed by Nch values.

## MW¶

Component molecular weights. No unit; followed by Nch values.

## SHIFT¶

Component dimensionless shift factors for the Peneloux volume shift.

## OMEGAA¶

Non-default Omega A values for the equation of state.

## OMEGAB¶

Non-default Omega B values for the equation of state.

## BIC¶

Binary interaction coefficients. As series of keywords specifying the binary coefficients as a lower triangular matrix. So the first BIC will specify the binary interaction coefficient between component 2 and component 1; the next BIC will specify the two binary interaction coefficients between component 3 and components 1 and 2, and so on – a total of Nch.(Nch-1)/2 values are required.

## GCOND¶

Specifies a gas condensate reservoir (all one phase hydrocarbon states are gas).