About Enhanced Oil Recovery


The three stages of oil recovery offer diminishing returns. EER's Bio Remedial Recovery is a unique technology with substantial advantages over other established enhanced recovery methods.

 The Three Stages of Petroleum Oil Recovery

Oil is typically recovered in three increasingly difficult stages:

Primary Recovery

The primary recovery of oil, or “easy oil”, occurs under the natural pressure and flow characteristics of the oil in the well. It does not require the introduction of any other substances into the well.

This primary stage of recovery will typically recover up to 15% of the total oil resources in the well.

Secondary Recovery

In the secondary recovery stage, recovery methods are used to increase the underground pressure on the oil sufficiently to move the remaining oil in the well. Predominantly, water and oil are used to flood the well to hold the pressure in the reservoir and to sweep the oil towards the producing wells.

This secondary stage of recovery will typically recover up to 20% of the total oil resources in the well. Between the primary and secondary stages of recovery, therefore, a combined 35% of the oil originally in place is able to be produced. The remaining 65% of oil that remains in the reservoir is typically defined as “unproducible”.

The remaining unproducible oil is “trapped” in the native rock in the reservoir, held by tension between the oil and water and the oil and rock surfaces. There is no process that can recover all of the remaining oil, but a number of processes can recover some of the remaining oil. These tertiary processes are collectively known as Enhanced Oil Recovery (“EOR”).

Tertiary Recovery

the three stages of oil recovery

EOR may involve any one or more of the following methods:

  • Injecting gases (eg: carbon dioxide), known as “flooding”, into the reservoir to increase pressure on the oil;
  • Injecting steam or hot water to decrease the viscosity of the oil to stimulate oil and gas flow;
  • Using Chemically Induced Enhanced Oil Recovery (“CEOR”) to “sweep” oil off the rock and decrease the viscosity of the oil;
  • Using microbially enhanced oil recovery to also reduce the viscosity of the oil.

The use of any one or more of these methods will typically recover a further 10% to 15% of the total oil resources in the well. The three stages of recovery will, therefore, recover less than 50% of all oil in any given well.



The Downsides of Other EOR Methods

The very obvious upside of EOR is that it dramatically increases the amount of oil that can be produced by oil wells.

There are, however, a number of downsides associated with certain EOR methods, including:

  • Carbon dioxide flooding requires significant capital investment, and the need for a carbon dioxide source and pipeline;

Carbon dioxide gassing in enhanced oil recovery

  • Steam injection also requires significant capital investment, and uses large amounts of energy to produce the steam;


  • Chemical Sweeping or CEOR is an expensive solution (due to the cost of producing the chemicals required) and can cause reservoir damage as well as environmental damage through toxicity;


  • Microbially enhanced oil recovery requires constant feed source for the microbes.




The EER Advantage

The unique BRRTM Process has been developed to specifically overcome the main disadvantages of EOR. In particular, the two-step BRRTM Process:

  • Reduces the need of microbially enhanced oil recovery to constantly feed the microbes, saving cost and eliminating the need to source feed;
  • Uses naturally occurring and totally biodegradable bio-surfactants, ensuring that the BRR (TM) Process is an environmentally friendly recovery method; and
  • Uses the existing water flooding infrastructure, saving capital cost.

EER is confident that the BRRTM Process will recover as much or more oil from each well as any other EOR method, and that it can be applied to a greater range and number of wells than any other single EOR method.