There are two main factors driving this growth. One is that as old fields reach the end of their productive life, it becomes necessary to use water or steam to chase out the last traces of hydrocarbon.
The other factor is that as older fields are exploited, it becomes necessary to turn to non-traditional resources such as tar sands and gas shale. These also require water-intensive technologies such as steam-assisted gravity drainage or fracking (see story in this month’s GWI).
The result is that the ratio of water required per barrel of oil or cubic foot of gas is rising quickly. For example, it takes 11 barrels of water to transport and separate each barrel of bitumen from the Canadian tar sands.
Meeting the growing water needs of the oil and gas industry is an interesting challenge. Whereas cities tend to grow up around freshwater resources, oil and gas fields don’t show the same forethought. Even Canada, which is one of the most water-rich countries in the world, will struggle to find the water it needs in Alberta, where the tar sands are located. Off-shore facilities also face difficulties: seawater contains too many sulphates to be used directly for well injection. Some form of membrane softening is required.
On top of the process water needs of the industry, there is a significant business in cleaning up the wastewater, or produced water, that comes out of the ground with the oil. In North America, the ratio is 12 barrels of produced water for each barrel of oil.
It is a great market for companies like GE, Siemens, Veolia, and Aquatech. But from a broader perspective, the increased demand for water in the oil and gas sector is likely to lead to greater competition for water resources, and conflicts with agricultural and urban water users. Besides being criticised for creating greenhouse gases, big oil is likely to encounter more complaints about its use of water. That is unless it can figure out a collaborative way forward.
Projects like Aquatech’s Mukhaizna facility for Occidental Petroleum in Oman, or Veolia’s San Ardo project for Chevron, are the way ahead. They recycle the produced water as process water, and return the excess to nature in such a way that others can benefit from it. This is a great solution where oil wells are net producers of water, but where they are net consumers, and they compete with other users, there is no such win-win solution. In those circumstances, the best solution would be for oil companies to invest in shared water production facilities which also benefit local communities. This kind of thinking will make the water and energy nexus real.
