Updated November 2022
On this page, we provide the following performance data:
- enhanced oil recovery water use – sector summary
- enhanced oil recovery water use – company performance
Enhanced oil recovery (EOR) improves hydrocarbon recovery by injecting fluids into a hydrocarbon reservoir to increase or maintain reservoir pressure, displace hydrocarbons to production wells, or alter reservoir fluids to improve hydrocarbon flow.
There are two types of EOR projects:
- conventional, which extracts crude oil
- nonthermal in situ, which extracts heavy oil or bitumen
In most EOR schemes, water is used as the only injection fluid to carry additives, such as polymers or surfactants, or as a chase fluid that follows the primary fluid to help push remaining oil towards the production wells. In situ EOR may also use fluids other than nonsaline water to enhance production, such as polymers, noncondensable gases, or hydrocarbon gases.
What is "make-up" water for an EOR project?
Make-up water is nonsaline or alternative water added to replace the water injected into an oil reservoir that does not return to surface. It may also replace recycled water because some produced water cannot be treated for further reuse and must be disposed of as wastewater.
How do we measure performance?
The primary metric used for comparing nonsaline water use performance is water use intensity. The intensity is calculated as the volume of nonsaline water used (in barrels) divided by the barrels of oil equivalent (BOE) produced in a calendar year. Nonsaline water intensity varies based on the type of fluid being injected, scheme age, and reservoir geology and characteristics.
All EOR schemes active in 2021 are considered in this report, regardless of their nonsaline water use.
How does the project life cycle affect water use intensity?
Nonsaline water use intensity is closely related to the age of the EOR project. After start-up, EOR projects quickly transition from using mostly make-up water to mostly recycled produced water. However, as schemes age, hydrocarbon production starts to decrease, which can result in increased nonsaline water use intensity. Generally, the longer an EOR project operates, the higher its nonsaline water intensity.
There are several other reasons why an older EOR scheme might have a higher nonsaline water intensity, not all related to where the schemes are in their life cycle:
- The scheme may have been built when nonsaline water use was of less concern. Consequently, infrastructure may have been built to standards unsuitable for handling alternatives to nonsaline water.
- Over time, as hydrocarbon production typically decreases, so too does revenue. Costs to convert to alternative water sources may be uneconomical.
- Companies may have historical water licences that do not expire and allow for ongoing use of nonsaline water sources.
- As a scheme matures, more water is needed to maintain the reservoir pressure to sustain hydrocarbon production.
- The type of EOR scheme (e.g., polymer floods) may require some nonsaline water as some polymers are very sensitive to water quality.
Using nonsaline water for EOR instead of alternative water can be a practical choice when abundant nonsaline water sources nearby can sustain the operation with little risk to the local environment.
Companies have made efforts to use less nonsaline water across all ages of EOR schemes.
EOR operators used about 10 per cent of their nonsaline water allocation in 2021 (see the following figure).
Total Water Use
In 2021, there were 860 EOR schemes in Alberta, of which 701 were injecting water, but only 15 per cent of those 701 schemes used nonsaline water. Like other extraction technologies, EOR requires make-up water because not all water used during operations is recoverable.
Directive 065: Resources Applications for Oil and Gas Reservoirs outlines nonsaline water use requirements. Before resorting to using nonsaline water, operators must fully investigate nonsaline water alternatives and submit evidence to the AER confirming no practical alternative water sources are available. However, alternative water sources are not always available, and some older projects are unable to handle saline or recycled water. Also, highly saline water can lower a product's quality. Some EOR operations use specialized polymers that are very sensitive to water quality. In those cases, the use of alternative water sources is not always feasible. These factors can affect the amount of nonsaline water an operation uses.
In 2021, EOR operations used more than 188 million cubic metres (m3) of water to produce over 103 million BOE (see the following figure). Of the total water used, over 94 per cent (176 million m3) was recycled, and the rest was make-up water.
In 2021, EOR companies used just under 12 million m3 of make-up water. Companies used 9.6 million m3 of nonsaline make-up water (80 per cent of total make-up water) and 2.4 million m3 of alternative make-up water (20 per cent of total make-up water). Alternative make-up water includes saline groundwater and produced water from other nearby EOR schemes.
Overall, make-up water use has declined almost 28 per cent since 2017, in line with the decline in total water use; the proportions of nonsaline and alternative water have been relatively stable over that period.
Water Use Intensity
Water use intensity refers to the amount of nonsaline water used to produce one BOE. In 2021, EOR companies used about 10 per cent (9.6 million m3 ) of the nonsaline water allocated, producing over 103 million BOE. For each BOE produced, EOR used 0.58 barrels of nonsaline water.
Between 2017 and 2021, nonsaline make-up water use for EOR decreased by 28 per cent while production decreased by 9 per cent, resulting in a 22 per cent improvement in nonsaline water use intensity. These changes are mainly due to reduced EOR activity across the province.
In the following figures, operations that don't use nonsaline water will show as having zero nonsaline water use intensity. These operations may still use recycled water or alternatives to nonsaline water.
To make meaningful comparisons, we compare the data of companies with similar experiences and expertise based on their annual hydrocarbon production. In the figures below, companies are sorted by their BOE production over the calendar year. The figures default to display all companies, which can be changed using the "Company volume" filter.
The tool below can be used to search the company volume for a specific company.
Water Use Intensity
A small number of operations can make a big difference in the EOR sector's overall performance. For example, three projects accounted for 55 per cent of the total nonsaline water volume for EOR in 2021, likely because of their large scale, including the large number of injection wells they have.
We also see this reflected in the nonsaline water use intensity of companies operating multiple schemes. A single scheme with a high nonsaline water use intensity can disproportionally affect a company's overall water use intensity, overshadowing the company's schemes with low water use intensities.
The following figure shows the overall nonsaline water use intensity for EOR by company.
An EOR scheme's age has a noticeable effect on nonsaline water use intensity. The average nonsaline water use intensity by age in 2021 is shown in the left-hand figure below.
The nonsaline water use intensity by age for all EOR companies is shown below in the left-hand figure. Select a company size, company name or scheme type from the filter and you will see the nonsaline water use intensity below in the right-hand figure based on your selection. This will make it possible to compare the specific water use intensity to the average EOR sector.
The following figure provides details on water use and hydrocarbon production by company.
Five-Year Trend Data
The following figures show five-year trend data on water use, hydrocarbon production, and nonsaline water use intensity.