Phase Behavior and ThermodynamicsPVT Properties

Glaso Undersaturated Oil Formation Volume Factor Formula

B_o=B_{ob}\exp[c_o(p_b-p)]

Glaso Undersaturated Oil Formation Volume Factor calculates undersaturated oil formation volume factor for pvt properties workflows in phase behavior and thermodynamics.

Calculate

How engineers use this formula

Use this formula when the listed inputs (B_ob, c_o, p_b, p) are known and the assumptions behind the cited pvt properties relationship match the engineering case being checked.

Assumptions

Input values are representative for the well, reservoir, fluid, or equipment case being evaluated.
The declared units match the field-unit constants used in the formula.
The cited formula applies to the selected petroleum engineering workflow.

Limitations

The calculation does not replace a full engineering model or operating procedure.
Accuracy depends on the source correlation, assumptions, input quality, and unit consistency.

Common mistakes

Mixing unit systems without converting the inputs.
Using default example values as field recommendations.
Applying the formula outside the source assumptions.

Default example

Using the default inputs, B_o equals 1.315723 RB/STB.

B_obRB/STB

1.3210909284519903

c_o1/psi

0.000013867833333333335

p_bpsi

2706.4119585411386

ppsi

3000

Inputs

B_ob

RB/STB

Oil Formation Volume Factor at Bubble Point

c_o

1/psi

Oil Compressibility Above Bubble Point

p_b

psi

Bubble Point Pressure

p

psi

Pressure

Outputs

B_o

RB/STB

Undersaturated Oil Formation Volume Factor

B_ob

RB/STB

Oil Formation Volume Factor at Bubble Point

c_o

1/psi

Oil Compressibility Above Bubble Point

p_b

psi

Bubble Point Pressure

p

psi

Pressure

Source and review

reviewed

Oil Correlations - Glaso (North Sea Oil), Glaso, O., IHS Harmony, Petroleum Office

Glaso, O. 1980. Generalized Pressure-Volume-Temperature Correlations, Journal of Petroleum Technology, SPE-8016-PA; IHS Harmony and Petroleum Office oil FVF documentation.

Source