Units¶

Overview¶

BORES uses oil-field units throughout the entire framework. This is the most common unit system in petroleum engineering in North America, and it is the system used by the empirical correlations that BORES implements (Standing, Vazquez-Beggs, Hall-Yarborough, etc.). Using a consistent unit system eliminates the need for unit conversions inside the simulator and reduces the risk of conversion errors.

If you are accustomed to SI units, you will need to convert your input data to oil-field units before passing it to BORES. The conversion tables below cover the most common quantities. There is no built-in unit conversion system in BORES, so conversions must be done externally (using NumPy, pint, or manual multiplication).

Standard Unit System¶

Pressure¶

Temperature¶

Length¶

Area and Volume¶

Flow Rates¶

Fluid Properties¶

Rock Properties¶

Time¶

import bores

one_day = bores.Time(days=1)          # 86400.0 seconds
one_year = bores.Time(years=1)        # 31557600.0 seconds
combined = bores.Time(days=30, hours=6)  # 2613600.0 seconds

Dimensionless Quantities¶

Common Conversions from SI¶

If your data is in SI units, use these conversion factors:

Example Conversion¶

import numpy as np

# Convert SI pressure data to oil-field units
pressure_mpa = np.array([20.0, 25.0, 30.0])  # MPa
pressure_psi = pressure_mpa * 145.0377         # psi

# Convert SI permeability to oil-field units
perm_m2 = 1e-13                                # m^2
perm_md = perm_m2 * 1.01325e15                 # mD (= 101.325 mD)

# Convert Celsius to Fahrenheit
temp_c = 93.3                                  # Celsius
temp_f = temp_c * 9.0 / 5.0 + 32.0            # Fahrenheit (= 200 F)

Standard Conditions¶

BORES uses the following standard (surface) conditions, consistent with petroleum industry conventions:

These are the conditions at which surface volumes (STB, SCF) are defined. Formation volume factors convert between reservoir conditions and these standard conditions.

You can access these values programmatically through the constants system:

import bores

print(bores.c.STANDARD_PRESSURE)     # 14.696 psi
print(bores.c.STANDARD_TEMPERATURE)  # 60.0 F

Sign Conventions¶

BORES uses the following sign conventions throughout the library: