What is recovery factor?

Recovery factor (RF) is the ratio of recoverable reserves to original hydrocarbons in place, expressed as a percentage. An RF of 35% means 35% of the oil or gas in the reservoir can be economically produced.

What is a typical oil recovery factor?

Primary recovery under solution gas drive typically yields 5–15% RF. Water drive or pressure maintenance can reach 35–60%. Enhanced oil recovery (EOR) methods such as CO2 flooding or steam injection can push RF above 60% in favorable reservoirs.

What is OOIP and how is it calculated?

OOIP (Original Oil In Place) is the total volume of oil in the reservoir before production. The volumetric formula is: OOIP = (GRV × porosity × (1 − Sw)) / Bo, where GRV is gross rock volume, Sw is water saturation, and Bo is the oil formation volume factor.

What does the formation volume factor (Bo) represent?

Bo is the ratio of the volume of oil at reservoir conditions to the volume of oil at surface (stock-tank) conditions. Gas dissolved in oil expands when pressure drops at surface, so reservoir oil shrinks — Bo is typically 1.05–2.0 RB/STB for most reservoirs.

How is gas recovery factor different from oil RF?

For gas, OGIP uses the gas formation volume factor Bg (expressed in Mcf/scf or res bbl/Mscf). Gas RF is generally higher than oil RF — depletion-drive gas reservoirs often achieve 70–90% RF because gas expands strongly as pressure drops.

What recovery efficiency value should I use?

Recovery efficiency (Er) depends on drive mechanism and reservoir quality. Use 0.10–0.25 for solution gas drive, 0.35–0.60 for active water drive, and 0.60–0.85 for high-quality gas reservoirs under depletion drive. EOR projects may exceed 0.70 for oil.

Recovery Factor Calculator

Name: Recovery Factor Calculator
Availability: InStock
Author: Nham Vu

Enter reservoir properties to calculate the oil or gas recovery factor using the volumetric method.

Fluid Type

Gross Rock Volume (GRV)

Total rock volume including reservoir, non-reservoir, and fluid-filled rock.

Porosity φ (fraction)

Enter as a decimal (e.g. 0.20 for 20% porosity).

Water Saturation S_w (fraction)

Fraction of pore space occupied by water (connate water).

Oil Formation Volume Factor B_o (RB/STB)

Reservoir-to-surface volume ratio. Typical oil: 1.05–2.0 RB/STB.

Recovery Efficiency E_r (fraction)

Fraction of movable hydrocarbons recovered (drive mechanism efficiency).

OOIP

—

MMSTB

Recovery Factor

—

RF (%)

Recoverable Reserves

—

MMSTB

Hydrocarbon Pore Volume

—

acre-ft

Calculation Breakdown

Results will appear here after calculation.

Typical Recovery Factors by Drive Mechanism

Drive Mechanism	RF Range	Notes
Solution Gas Drive (Oil)	5–25%	Least efficient; pressure depletes quickly
Gas Cap Drive (Oil)	20–40%	Expanding gas cap maintains pressure
Water Drive (Oil)	35–60%	Most effective natural drive for oil
EOR / Injection (Oil)	50–80%	CO2, steam, polymer flooding
Depletion Drive (Gas)	70–90%	Gas expansion highly efficient
Water Drive (Gas)	50–70%	Water influx traps residual gas

Summary

Enter reservoir properties to calculate the oil or gas recovery factor using the volumetric method.

How it works

Enter the reservoir gross rock volume (GRV) in acre-feet or cubic meters.
Specify porosity (fraction of rock that is void space) and water saturation (fraction of pore space occupied by water).
Enter the formation volume factor (Bo for oil, Bg for gas) to convert reservoir volumes to surface conditions.
Set the recovery efficiency — the fraction of movable hydrocarbons that can actually be produced.
The calculator computes OOIP or OGIP and then applies the recovery efficiency to get the recovery factor (RF).
Results update instantly as you adjust any input.

Use cases

Estimate how much oil or gas can be commercially recovered from a new discovery.
Compare drive mechanism efficiencies (water drive vs. solution gas drive vs. gas cap drive).
Screen field development scenarios with different EOR (enhanced oil recovery) strategies.
Support reserves classification (proved, probable, possible) under SPE-PRMS guidelines.
Academic and training exercises in reservoir engineering courses.
Quick sanity-check on volumetric OOIP/OGIP before running a full simulation.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu