Oil Bubble Radius for Circular Drainage Area Formula
Oil Bubble Radius for Circular Drainage Area calculates oil bubble radius for material balance and production workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (N_p, phi, h, S_wi, B_o, B_oi, S_o) are known and the assumptions behind the cited material balance and production 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, r_ob equals 259.628813 ft.
100000
0.2
50
0.25
1.2
1.1
0.5
Inputs
N_p
bblWell Current Cumulative Oil Production
phi
fractionPorosity
h
ftThickness
S_wi
fractionInitial Water Saturation at Bubble Point Pressure
B_o
bbl/STBOil Formation Volume Factor
B_oi
bbl/STBInitial Oil Formation Volume Factor
S_o
fractionCurrent Oil Saturation
Outputs
r_ob
Oil Bubble Radius
N_p
Well Current Cumulative Oil Production
h
Thickness
phi
Porosity
Source and review
reviewedAdvanced Reservoir Engineering, Ahmed, T., McKinney, P. D. (2005)
Ahmed, T. and McKinney, P. D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter 4, Page 313.
Source