Optimizing Water Use

The need to optimize our water use applies to all of our activities and businesses. In 2007, we published a on this topic to:

• Share best practices across Total.
• Help our sites set targets for reducing their water use.

We focus in particular on sites where industrial water requirements compete with other important uses, such as household consumption and agriculture, tailoring our solutions to the local context and to seasonal constraints.

Preserving Water Quality

When oil or gas is extracted from a reservoir, water is also brought to the surface. It is known as produced water. Although initially low, the amount of produced water increases as the field matures.

Our priority is to reinject produced water into the reservoirs. This allows us to maintain reservoir pressure and enhance oil recovery, as the water acts as a piston, pushing the oil toward the wells. It also means that the produced water is recycled, limiting both use and discharges.

This approach requires the implementation of complex processes like membrane ultrafiltration to ensure that the recycled water will not interfere with reservoir permeability or impede the flow of oil to the well. Concretely, this means preventing the microchannels that run through the reservoir from getting clogged up.

If reinjection is not feasible, water is treated before being discharged into the natural environment. For each site, we limit the oil content of discharges to 30 milligrams per liter in offshore areas. Onshore and in coastal waters, our target is a maximum of 10 milligrams per liter.

Upgrading Our Facilities and Deploying Best Practices

The Feyzin Refinery, near Lyon. View of the wastewater
treatment plant.

More generally, we are implementing effluent quality improvement programs and upgrading or retrofitting our facilities as needed, on a case-by-case basis. We also encourage our teams to share best practices to ensure their widespread use.

• At the Feyzin refinery in France, the construction of a dissolved-air flotation unit, which separates water from suspended matter such as oils and solids, has reduced the overall chemical oxygen demand (COD) of discharged water by 20%.
• At the Grandpuits refinery, also in France, better management of effluents has increased recycling and reduced the facility’s water use by 14%.
• At the Antwerp refinery in Belgium, the oil content of discharges has been reduced by 55% thanks to the strict application of best operating practices.

Proactively Responding to Changing Regulations

We pay special attention to trace pollutants and hazardous substances. In 2009, we launched a research program on hazardous substances at our major Chemicals facilities in Europe, which continued in 2010 with field analysis campaigns.

Our aim is to proactively respond to the tightening of chemical and environmental quality requirements for receiving water bodies such as oceans and rivers. This trend is reflected in many countries’ regulations on water quality and enshrined in the European Union’s Water Framework Directive.