• Oil Formation Volume Factor
General Equation    
 
Input Field(s)    
Volume of oil+dissolved gases (Vor) rb
Volume of oil produced at STB (Vop) stb
       
Output Field(s)      
Formation Volume Factor (Bo) rb/stb
 
At or Below Bubble Point (Correlation)  
 
Input Field(s)    
Gas Oil Ratio (Rso) scf/stb
Gas gravity (Sg)  
Oil gravity (So)  
Temperature (T) deg.F
       
Output Field(s)      
Formation Volume Factor (Bo) rb/stb
     
Above Bubble Point (Correlation)  
 
Input Field(s)    
Bo at Bubble Point (Bob) rb/stb
Reservoir Pressure (P) psi
Bubble point pressure (Pb) psi
Oil Compressibility (co) 1/psi
       
Output Field(s)      
Formation Volume Factor (Bo) rb/stb

  • Calculation Guide
  • Overview
    • The Oil Formation Volume Factor is a measure of the reduction in the volume of crude oil as it is produced.
  • Equations
    • General Equation
    • --------------------------------------------------
    • Bo = Vor/Vop
    • Bo - Formation Volume Factor (rb/stb)
    • Vor - Volume of oil + dissolved volatiles at reservoir conditions (rb)
    • Vop - Volume of produced oil under stock tank conditions (stb)
    • --------------------------------------------------
    • Standing Correlation - Below Bubble Point Pressure
    • Bo = 0.972 + 0.000147 F 1.175
    • --------------------------------------------------
    • F = Rso (Sg/So) 0.5+ 1.25 T
    • Rso - Solution GOR (scf/stb)
    • Sg - Gas Gravity
    • So - Oil Gravity
    • T - Temperature (deg.F)
    • --------------------------------------------------
    • Correlations - Above Bubble Point Pressure
    • Bo = Bob exp[co (pb - p)]
    • --------------------------------------------------
    • Bob = Formation volume factor at Bubble Point (rb/stb)
    • co - Oil Compressibility (1/psi)
    • Pb - Bubble Point Pressure (psi)
    • P - Reservoir Pressure (psi)
  • Assumptions
    • Single Phase
  • Reference
    • Practical Enhanced Reservoir Engineering Satter, A; Iqbal, G; Buchwalter, J;
  • Unit Conversion Tool