pyscal.gaswater

Object to represent GasWater, implemented as a Container object for one WaterOil and one GasOil object

class pyscal.gaswater.GasWater(swirr=0.0, swl=0.0, sgl=0.0, swcr=0.0, sgrw=0.0, sgcr=0.0, h=None, tag='', fast=False)[source]

A representation of two-phase properties for gas-water

Internally, this class handles gas-water by using one WaterOil object and one GasOil object, with dummy parameters for oil.

Parameters:

  • swirr (float) – Irreducible water saturation for capillary pressure

  • swl (float) – First water saturation point in outputted tables.

  • sgl (float) – Minimum gas saturation in a gas paleozone.

  • swcr (float) – Critical water saturation, water is immobile below this

  • sgrw (float) – Residual gas saturation after water flooding.

  • sgcr (float) – Critical gas saturation, gas is immobile below this

  • h (Optional[float]) – Saturation intervals in generated tables.

  • tag (str) – Optional text that will be included as comments.

  • fast (bool) – Set to True if you prefer speed over robustness. Not recommended, pyscal will not guarantee valid output in this mode.

SGFN(header=True, dataincommentrow=True)[source]

Produce SGFN input for Eclipse reservoir simulator.

The columns sg and krg are outputted and formatted accordingly.

Meta-information for the tabulated data are printed as Eclipse comments.

Parameters:

  • header (bool) – boolean for whether the SGFN string should be emitted. If you have multiple satnums, you should have True only for the first (or False for all, and emit the SGFN yourself). Defaults to True.

  • dataincommentrow (bool) – boolean for wheter metadata should be printed, defaults to True.

SWFN(header=True, dataincommentrow=True)[source]

Produce SWFN input to Eclipse

The columns sw, krw and pc are outputted and formatted accordingly.

Meta-information for the tabulated data are printed as Eclipse comments.

Parameters:

  • header (bool) – boolean for whether the SWFN string should be emitted. If you have multiple satnums, you should have True only for the first (or False for all, and emit the SWFN yourself). Defaults to True.

  • dataincommentrow (bool) – boolean for wheter metadata should be printed, defaults to True.

add_LET_gas(l=2.0, e=2.0, t=2.0, krgend=1.0)[source]

Add krg data through the LET parametrization

A column named ‘krg’ will be added. If it exists, it will be replaced.

Parameters:

  • l (float) – LET parameter

  • e (float) – LET parameter

  • t (float) – LET parameter

  • krgend (float) – value of krg at swl

Return type:

None

add_LET_water(l=2.0, e=2.0, t=2.0, krwend=1.0, krwmax=None)[source]

Add krw data through LET parametrization

The LET model applies for sw < 1 - sgrw. For higher water saturations, krw is linear between krwend and krwmax.

krwmax will be ignored if sorw is close to zero.

Parameters:

  • l (float) – LET parameter

  • e (float) – LET parameter

  • t (float) – LET parameter

  • krwend (float) – value of krw at 1 - sorw

  • krwmax (Optional[float]) – maximal value at Sw=1. Default 1

Return type:

None

add_corey_gas(ng=2.0, krgend=1.0)[source]

Add krg data through the Corey parametrization

A column named ‘krg’ will be added. If it exists, it will be replaced.

Parameters:

  • ng (float) – Corey parameter for gas

  • krgend (float) – value of krg at swl.

Return type:

None

add_corey_water(nw=2.0, krwend=1.0, krwmax=None)[source]

Add krw data through the Corey parametrization

A column named ‘krw’ will be added. If it exists, it will be replaced.

The Corey model applies for sw < 1 - sgrw. For higher water saturations, krw is linear between krwend and krwmax.

krwmax will be ignored if sgrw is close to zero

Parameters:

  • nw (float) – Corey parameter for water.

  • krwend (float) – value of krw at 1 - sgcr.

  • krwmax (Optional[float]) – maximal value at Sw=1. Default 1

Return type:

None

add_simple_J(a=5.0, b=-1.5, poro_ref=0.25, perm_ref=100.0, drho=300.0, g=9.81)[source]

Add capillary pressure function from a simplified J-function

This is the RMS version of the coefficients a and b, the formula used is

\[J = a S_w^b\]

J is not dimensionless in this equation. The capillary pressure will be in bars.

This is identical to the also seen formula

\[J = 10^{b \log(S_w) + \log(a)}\]

\(S_w\) in this formula is normalized with respect to the swirr variable of the WaterOil object.

Parameters:

  • a (float) – a coefficient

  • b (float) – b coefficient

  • poro_ref (float) – Reference porosity for scaling to Pc, between 0 and 1

  • perm_ref (float) – Reference permeability for scaling to Pc, in milliDarcy

  • drho (float) – Density difference between water and oil, in SI units kg/m³. Default value is 300

  • g (float) – Gravitational acceleration, in SI units m/s², default value is 9.81

Return type:

None

Returns:

None. Modifies pc column in self.table, using bar as pressure unit.

add_simple_J_petro(a, b, poro_ref=0.25, perm_ref=100.0, drho=300.0, g=9.81)[source]

Add capillary pressure function from a simplified J-function

This is the petrophysical version of the coefficients a and b, the formula used is

\[J = \left(\frac{S_w}{a}\right)^{\frac{1}{b}}\]

which is identical to

\[J = 10^\frac{\log(S_w) - \log(a)}{b}\]

J is not dimensionless in this equation.

\(S_w\) in this formula is normalized with respect to the swirr variable of the WaterOil object.

Parameters:

  • a (float) – a coefficient, petrophysical version

  • b (float) – b coefficient, petrophysical version

  • poro_ref (float) – Reference porosity for scaling to Pc, between 0 and 1

  • perm_ref (float) – Reference permeability for scaling to Pc, in milliDarcy

  • drho (float) – Density difference between water and oil, in SI units kg/m³. Default value is 300

  • g (float) – Gravitational acceleration, in SI units m/s², default value is 9.81

Return type:

None

Returns:

None. Modifies pc column in self.table, using bar as pressure unit.

crosspoint()[source]

Calculate the sw value where krg == krw.

Accuracy of this crosspoint depends on the resolution chosen when initializing the saturation range (it uses linear interpolation to solve for the zero)

Return type:

Optional[float]

Returns:

The gas saturation where krw == krg, for relperm linearly interpolated in water saturation.

property krgcomment: str

Get a string representation describing krg

property krwcomment: str

Get a string representation describing krw

plotkrwkrg(mpl_ax=None, color='blue', alpha=1, linewidth=1, linestyle='-', marker=None, label='', logyscale=False)[source]

Plot krw and krg

If the argument ‘mpl_ax’ is not supplied, a new plot window will be made. If supplied, it will draw on the specified axis.

selfcheck()[source]

Run selfcheck on the data.

Performs tests if necessary data is ready in the object for printing Eclipse include files, and checks some numerical properties (direction and monotonicity)

Return type:

bool

property sgcomment: str

Get a string representation of the endpoints used for gas

property swcomment: str

Get a string representation of the endpoints used for water

property swcr: float

Get the swcr

property swirr: float

Get the swirr, irreducible water saturation used for pc-init

property swl: float

Get the swl

property tag: str

Get the user configured tag

pyscal.gaswater.is_documented_by(original)[source]

Decorator to avoid duplicating function docstrings