pyResToolbox MCP Server

Calculate oil bubble point pressure (Pb).

CRITICAL PVT PROPERTY - The bubble point is the pressure at which gas first begins to evolve from solution in oil. Essential for all oil reservoir calculations.

Parameters:

• api (float, required): Oil API gravity in degrees. Valid range: 0-100. Typical values: 20-50. Example: 35.0 for medium gravity crude.

• degf (float, required): Reservoir temperature in degrees Fahrenheit. Valid range: -460 to 1000. Typical: 100-300°F. Example: 180.0.

• rsb (float, required): Solution gas-oil ratio at bubble point in scf/stb. Must be ≥ 0. Typical: 100-3000 scf/stb. Example: 800.0.

• sg_g (float, optional, default=0.0): Gas specific gravity (air=1.0). Valid range: 0-3. Typical: 0.6-1.2. Example: 0.75 for associated gas.

• method (str, optional, default="VALMC"): Correlation method. Options: "STAN", "VALMC", "VELAR". VALMC recommended for wider applicability.

Method Selection:

• VALMC (Valko-McCain 2003): Recommended. Best for wide range of conditions. Use for: Most applications, high GOR oils, wide temperature ranges.

• STAN (Standing 1947): Classic correlation. Use for: Standard conditions, quick estimates, compatibility with older methods.

• VELAR (Velarde 1997): Alternative method. Use for: Specific regional correlations, comparison studies.

Returns: Dictionary with:

• value (float): Bubble point pressure in psia

• method (str): Method used

• units (str): "psia"

• inputs (dict): Echo of input parameters

Common Mistakes:

• Using separator temperature instead of reservoir temperature

• Confusing rsb (solution GOR at bubble point) with separator GOR

• Using gas gravity from wrong separator stage

• Temperature in Celsius instead of Fahrenheit

Example Usage:

Expected result: Pb ≈ 3000-4000 psia for typical oil.

Note: If Pb > reservoir pressure, reservoir is undersaturated (no free gas). If Pb < reservoir pressure, reservoir is saturated (gas cap present).