Updated August 2019
In the Alberta Water Use Performance Report, we look at
Enhanced oil recovery (EOR) improves hydrocarbon recovery by injecting fluids into a hydrocarbon reservoir to add to 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, and
- non-thermal in situ, which extracts heavy oil or bitumen.
In the majority of EOR schemes, water is used as either the only injection fluid, carrying additives such as polymers or surfactants, or as a chase fluid. In situ EOR may also use fluids other than nonsaline water to enhance production, such as polymers, non-condensable gases, or hydrocarbon gases.
What is “make-up” water for an enhanced oil recovery project?
Make-up water is nonsaline or alternative water that is added to replenish the water in an oil reservoir and is not returned to surface. It also replaces recycled water in some cases, as some water cannot be treated any further for reuse and must be disposed of as wastewater.
The main metric used for comparing nonsaline water use performance is water use intensity. The intensity is based on the volume of nonsaline water in barrels used divided by the barrel of oil equivalent (BOE) produced in a calendar year. Nonsaline intensities will vary based on factors like the type of fluid being injected, scheme age, reservoir geology and characteristics, and what amount of an oil pool is being produced through EOR techniques.
Most EOR projects quickly transition from using mostly make-up water to using predominantly recycled produced water over the course of their life cycle. All EOR schemes active in 2018 are considered in this report, regardless of their nonsaline water use.
Water Use Throughout the Lifecycle
When it comes to EOR, nonsaline water use intensity is closely related to the age of the project. Generally speaking, the longer an EOR project has been operating, the higher its nonsaline water use intensity is.
There are several reasons why an older scheme may have a higher nonsaline water use intensity:
- The scheme may have been built when nonsaline water use was of less concern. As a result, infrastructure may have been built to standards unsuitable for handling alternatives to nonsaline water.
- Companies may have historical water licences that don’t expire and allow for ongoing use of nonsaline water sources.
- It may be needed 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.
- As an EOR scheme ages, its hydrocarbon production typically decreases, as does revenue. Costs to convert to alternative water sources may be uneconomical and could force a scheme to stop operating, leaving unproduced hydrocarbons in the reservoir that it could otherwise extract if it were to continue the use of nonsaline water.
Using nonsaline water for EOR instead of alternative water can be a practical choice if nonsaline water sources are both abundant and nearby, provided that they can sustain the operation while posing low risk to the local environment.
Companies have made efforts to use less nonsaline water use across all ages of EOR schemes.
EOR operators used roughly 11 per cent of their nonsaline water allocation in 2018.
The map below shows where EOR operators are using nonsaline water as a make-up source in Alberta. Zoom in to reveal more.
Total Water Use
Nearly 800 EOR schemes injected water in 2018, but only 17 per cent used nonsaline water. Similar to other extraction technologies, EOR requires make-up water because not all water used during operations can be recovered.
Directive 065: Resources Applications for Oil and Gas Reservoirs outlines nonsaline water use and requires operators to fully investigate alternatives to nonsaline water, and to submit evidence to the AER that there are no practical alternative saline water sources before resorting to nonsaline water. However, alternative water sources aren’t always available, and some older projects are unable to handle saline or recycled water. As well, highly saline water can lower a product’s quality. Some polymer EOR operations use specialized compounds that are very sensitive to the water used with them; in those cases, use of alternative water sources is not always feasible. This can affect the amount of nonsaline water an operation uses.
In 2018, almost 230 million cubic metres of water was used to produce nearly 114 million barrels of oil equivalent from EOR. Of the total water used, nearly 94 per cent (216 million cubic metres) was recycled, and the rest was make-up water.
EOR companies used over 3 million cubic metres of alternative make-up water in 2018, which included saline groundwater and produced water from other nearby EOR schemes.
Overall, water use and hydrocarbon production for EOR have been declining since 2014 because of the increasingly fewer EOR projects operating across the province. However, the proportional use of recycled and make-up water has stayed the same.
In 2018, just over 14 million cubic metres of make-up water was used for EOR, with nonsaline water accounting for about 78 per cent and alternative sources accounting for about 22 per cent.
Overall, make-up water use has declined almost 29 per cent since 2014, 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 water used to produce one BOE. In 2018, EOR used over 11 million cubic metres of nonsaline water (11 per cent of the nonsaline water allocated for EOR) to produce nearly 114 million BOE. This means that, for every one BOE produced, EOR used 0.61 barrels (bbl) of nonsaline water.
Between 2014 and 2018, nonsaline water use volumes for EOR decreased by 30 per cent while production decreased by 11 per cent. The production decline is mainly due to reduced EOR activity across the province. However, over this period, EOR has shown a 22 per cent improvement in its nonsaline water use intensity, as projects continue to move through the lifecycle.
In the following charts, 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 experience and expertise based on their annual hydrocarbon production. In the graphs below, companies are sorted by their BOE production over the past 12 months. The graphs default to display all companies; this can change this using the “Company volume” filter.
The tool below can be used to search the "Company volume" for a specific company.
Water Use Intensity
When it comes to EOR, a small number of operations can make a big difference in the sector’s overall performance. For example, the top three nonsaline water-using projects in Alberta accounted for 34 per cent of the total nonsaline water volume for EOR in 2018, likely because of the scale of the operations and the number of injection wells within them.
We also see this reflected in the nonsaline water use intensity of companies operating multiple schemes where a single scheme with high nonsaline water use intensity can disproportionally affect the overall intensity metric.
Below, overall nonsaline water use intensity for EOR is shown 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 2018 is shown in the chart to your left below.
In the chart below, companies are divided based on the age of their projects. Generally, companies using higher volumes of recycled and alternative make-up water have lower nonsaline water use intensities.
Five-Year Trend Data
To track performance over time, we have five-year trend data on companies’ water use, hydrocarbon production, and nonsaline water-use intensity below.