Recovery Factor

Recovery Factor is the amount of hydrocarbon that can be recovered or produced from a reservoir per unit volume of original in place. Mathematically, it can be written as follows:

RF = EUR / STOIIP *100 % for oil
RF = EUR / GIIP * 100 % for gas

where,
RF = Recovery Factor
EUR = Estimated Ultimate Recovery
STOIIP = Stock Tank Oil Originally in Place
GIIP = Gas Initially In Place

A wide range of parameters can influence the value of RF. It is an area of great interest for Reservoir Engineers to determine and justify the correct value of RF for given reservoir with a given depletion plan.

These factors can be listed as follows:

• Natural Factors
  • Reservoir Heterogeneity (Porosity, Permeability, Fracture, Reservoir Layering etc)
  • Reservoir Structure
  • Faults and their sealing
  • Sand Thickness
  • Fluid Contacts
  • Fluid Saturations
  • Drive Mechanism (Aquifer Drive, Solution Drive, Gas Cap etc)
  • Rock-Fluid Properties (i.e.Mobility Ratio)
• Man-made Factors
  • Well-Spacing
  • Depletion Plan
  • IOR/EOR implemented
  • Economics