bruges.rockphysics.fluids module

Fluid properties.

These functions implement equations from Batzle and Wang (1992), seismic properties of pore fluids. GEOPHYSICS, VOL. 57, NO. 11; P. 1396-1408,

copyright:2018 Agile Geoscience
license:Apache 2.0
bruges.rockphysics.fluids.rho_brine(temperature, pressure, salinity)[source]

The density of NaCl brine, given temperature, pressure, and salinity. The density of pure water is computed from rho_water(). Implements equation 27b from Batzle and Wang (1992).

Use scalars or arrays; if you use arrays, they must be the same size.

Parameters:
  • temperature (array) – The temperature in degrees Celsius.
  • pressure (array) – The pressure in pascals.
  • salinity (array) – The weight fraction of NaCl, e.g. 35e-3 for 35 parts per thousand, or 3.5% (the salinity of seawater).
Returns:

The density in kg/m3.

Return type:

array

bruges.rockphysics.fluids.rho_gas(temperature, pressure, molecular_weight)[source]

Gas density, given temperature (in deg C), pressure (in Pa), and molecular weight.

Parameters:
  • temperature (array) – The temperature in degrees Celsius.
  • pressure (array) – The pressure in pascals.
  • molecular_weight (array) – The molecular weight.
Returns:

The density in kg/m3.

Return type:

array

bruges.rockphysics.fluids.rho_water(temperature, pressure)[source]

The density of pure water, as a function of temperature and pressure. Implements equation 27a from Batzle and Wang (1992).

Use scalars or arrays; if you use arrays, they must be the same size.

Parameters:
  • temperature (array) – The temperature in degrees Celsius.
  • pressure (array) – The pressure in pascals.
Returns:

The density in kg/m3.

Return type:

array

bruges.rockphysics.fluids.v_brine(temperature, pressure, salinity)[source]

The acoustic velocity of brine, as a function of temperature (deg C), pressure (Pa), and salinity (weight fraction). Implements equation 29 from Batzle and Wang (1992).

Note that this function does not work at pressures above about 100 MPa.

Use scalars or arrays; if you use arrays, they must be the same size.

Parameters:
  • temperature (array) – The temperature in degrees Celsius.
  • pressure (array) – The pressure in pascals.
  • salinity (array) – The weight fraction of NaCl, e.g. 35e-3 for 35 parts per thousand, or 3.5% (the salinity of seawater).
Returns:

The velocity in m/s.

Return type:

array

bruges.rockphysics.fluids.v_water(temperature, pressure)[source]

The acoustic velocity of pure water, as a function of temperature and pressure. Implements equation 28 from Batzle and Wang (1992), using the coefficients in Table 1.

Note that this function does not work at pressures above about 100 MPa.

Use scalars or arrays; if you use arrays, they must be the same size.

Parameters:
  • temperature (array) – The temperature in degrees Celsius.
  • pressure (array) – The pressure in pascals.
Returns:

The velocity in m/s.

Return type:

array

bruges.rockphysics.fluids.wood(Kf1, Kf2, Sf1)[source]

Wood’s equation, per equation 35b in Batzle and Wang (1992).