Tertiary oil recovery, also referred to as enhanced oil recovery (EOR), involves the use of advanced methods to extract the remaining oil from reservoirs that have exhausted primary and secondary recovery techniques. EOR methods are expensive and complex, but they carry the potential to substantially increase oil production and prolong the lifespan of oil fields.

With easy-to-reach oil reserves being depleted, the oil industry is increasingly relying on EOR. EOR techniques can extend the duration of wells in oil fields that are proven and probable, where the chances of oil recovery are high.

This article seeks to examine different EOR methods and their economic advantages. It will also analyze the factors that influence the profitability of EOR undertakings, outlining how EOR can help oil companies to enhance their bottom line.

Understanding Tertiary Oil Recovery Techniques

The third phase of oil extraction, known as Tertiary oil recovery, concentrates on recovering oil that has not been extracted using primary or secondary recovery techniques.

Primary and secondary recovery methods rely on pressure differentials and the natural drive of the reservoir. In contrast, EOR processes alter the chemical or physical qualities of the oil, enhancing its flow and extraction.

Common tertiary oil recovery methods

Gas injection (CO2, N2)

Gas injection involves injecting natural gas, carbon dioxide, or nitrogen into the reservoir. The gas can either push the oil through the reservoir or mix with it, reducing its viscosity and improving its permeability. In the United States, this method accounts for almost 60% of EOR production.

Chemical injection (polymers, surfactants, alkalis)

Chemical injection utilizes polymers to enhance the efficacy of water floods, or surfactants to reduce the surface tension that prevents oil droplets from flowing across the reservoir. In the US, chemical techniques account for about 1% of EOR production.

Thermal recovery (steam flooding, in-situ combustion)

Thermal EOR involves the introduction of heat, such as steam injection, to reduce the oil’s viscosity and enhance its flow. Thermal methods account for over 40% of EOR production in the US, primarily in California.

How EOR methods improve oil recovery rates

EOR techniques are employed to enhance the recovery rates of oil by changing the chemical and physical properties of the oil, making it easier to extract from the reservoir. This enables the recovery of an additional 30 to 60% of the original oil in place in the reservoir.

Economic Analysis of Enhanced Oil Recovery Techniques

Cost-benefit comparison of primary, secondary, and tertiary recovery methods

Primary and secondary recovery methods are less expensive compared to EOR techniques, but they only extract a limited percentage of oil from the reservoir.

In contrast, EOR methods can substantially increase oil production and extend the lifespan of oil fields, despite their higher cost. As a result, EOR holds the potential to be a viable investment for oil companies.

Factors influencing the profitability of EOR projects

Oil prices

The profitability of EOR projects is largely dependent on oil prices. Many EOR techniques become questionable if the oil prices go below $60/bbl and seem uneconomical at or below $40/bbl.

Production costs

Production costs increase with the implementation of tertiary recovery methods as they become more complex and invasive, leading to higher expenses.

Government policies and incentives

Government policies and incentives, such as tax credits and research grants, can encourage the adoption of EOR techniques.

Environmental considerations

EOR projects must consider the environmental impact such as potential contamination of water sources or greenhouse gas emissions. Proper measures must be taken to ensure that these concerns are addressed.

Identifying Opportunities for EOR Implementation

Assessing the suitability of EOR techniques for specific reservoirs

Selecting an appropriate EOR technique is dependent on various factors, such as the reservoir characteristics, oil viscosity, and temperature.

Oil companies need to conduct a detailed evaluation of the reservoir’s geology, fluid properties, and existing infrastructure to determine which EOR method would be most suitable.

Evaluating the potential increase in oil recovery

Assessing the potential increase in oil recovery involves analyzing the effectiveness of the chosen EOR technique against the specific reservoir context. This necessitates conducting detailed reservoir simulations and pilot tests to determine the anticipated incremental oil production.

Analyzing the economic feasibility of EOR projects

Before embarking on an EOR project, oil companies must conduct an economic feasibility analysis, considering critical components such as the anticipated increase in oil recovery, production costs, oil prices, and possible environmental impacts.

This analysis is necessary to ascertain whether the EOR project is economically feasible, and the cost of production does not exceed the market price of oil. The prospective benefits must outweigh the expenses to begin a successful EOR project.

Optimizing EOR Operations for Maximum Profitability

Integrated reservoir management

Integrated reservoir management combines geological, geophysical, and engineering data to make informed decisions regarding EOR project design, implementation, and monitoring, optimizing EOR operations for maximum profitability.

Utilizing advanced technologies and digital solutions

Advanced technologies such as data analytics, machine learning, and artificial intelligence can provide real-time data and predictive models, enabling proactive decision-making and adaptive strategies. Using such technologies optimizes EOR operations and improves profitability.

Implementing best practices in EOR operations

Adherence to industry best practices, such as proper reservoir characterization, effective project management, and rigorous safety protocols, ensures the success of EOR projects, leading to profitability.

Monitoring and adjusting EOR strategies for continuous improvement

Continuous monitoring of EOR operations enables the identification of potential issues and the adjustment of strategies to improve efficiency and profitability. By doing so, EOR strategies can be continuously improved for maximum profitability.

Environmental and Social Benefits of EOR

Reducing greenhouse gas emissions through CO2 sequestration

EOR projects that utilize CO2 injection not only enhance oil recovery but also aid in mitigating climate change by sequestering carbon dioxide in the reservoir and effectively removing it from the atmosphere. This effectively reduces greenhouse gas emissions, resulting in a cleaner environment.

Increasing energy security and reducing dependence on foreign oil

Through increasing domestic oil production, EOR projects enhance energy security, lessening dependence on foreign oil imports. This can lead to significant savings, enhance the economy, and strengthen national security.

Supporting local communities through job creation and economic growth

EOR projects frequently create jobs and contribute to the economic growth of local communities, especially in regions with mature oil fields. This supports local communities by promoting economic activity and job creation, leading to a direct impact on the economy.


EOR plays a vital role in securing a prosperous future for the oil industry by maximizing the extraction of valuable resources, reducing environmental impacts, and supporting local economies.

To remain competitive and ensure long-term success, oil companies must invest in EOR technologies and strategies that optimize oil recovery, minimize environmental impacts and uphold social and economic growth.

If you are looking for a customized EOR solution for your company, get in touch with 21st Century Energy Solutions Inc. today!