Voidage Replacement Ratio Formula
Voidage Replacement Ratio calculates voidage replacement ratio for injection wells workflows in production engineering.
How engineers use this formula
Use this formula when the listed inputs (W_i, B_wi, G_i, B_ginj, N_p, B_o, W_p, B_wp, B_g, GOR, R_s) are known and the assumptions behind the cited injection wells 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, VRR equals 0.976357 dimensionless.
100000
1.02
0
0.005
70000
1.2
20000
1.02
0.005
0.8
0.6
Inputs
W_i
STBWater Injected
B_wi
rb/STBInjected Water Formation Volume Factor
G_i
MscfGas Injected
B_ginj
rb/MscfInjected Gas Formation Volume Factor
N_p
STBOil Produced
B_o
rb/STBOil Formation Volume Factor
W_p
STBWater Produced
B_wp
rb/STBProduced Water Formation Volume Factor
B_g
rb/MscfProduced Gas Formation Volume Factor
GOR
Mscf/STBProduced Gas-Oil Ratio
R_s
Mscf/STBSolution Gas-Oil Ratio
Outputs
VRR
Voidage Replacement Ratio
Source and review
reviewedPengTools Wiki. VRR; IHS Harmony material balance analysis theory, voidage replacement ratio definition.
Source