Which heavy metals contain the large amounts of produced water released into the North Sea each year from the offshore oil and gas industry? And how do metals affect the marine environment? DTU Offshore will investigate this question over the next 4 years with a grant of DKK 4.4 million from the VELUX FOUNDATION. More knowledge in this area is crucial for the regulation and ultimately the phasing out of oil and gas extraction at sea.
Produced water is the term for the water used in the offshore oil and gas industry, which is subsequently released into the sea from the production platforms. The water contains waste products from production, e.g. heavy metals, production chemicals, low-level radioactive material and dissolved oil.
There are many indications that produced water is harmful to the marine environment, but scientists do not know enough about the exact content of the water and thus about the specific harmful effects. However, new research suggests that the water may contain more heavy metals than previously assumed, and new measurements of heavy metals in different oil wells show that the occurrence of the heavy metals can vary by up to 1000 per cent from well to well.
A new research project from DTU Offshore will now map and measure the discharge of heavy and trace metals into produced water from a number of oil wells in the North Sea and document how it affects the marine environment. Using advanced analytical techniques, the researchers will measure the presence of trace metals, including copper, cadmium, lead, arsenic, tin, selenium and mercury in the water. The VELUX FOUNDATION has supported the project with DKK 4.4 million over the next three years.
"We know too little about what produced water contains and what consequences it has for marine areas. It is crucial to investigate so that we can make accurate demands on the oil and gas industry regarding discharges into the sea," emphasizes Charlotte Mogensen, who is head of the programme area A Sea in Balance.
Focus on underexposed area
The project is headed by senior researcher at DTU Offshore Karen Louise Feilberg, who, together with a PhD student and a postdoc, will now begin the analyses. She also points out that there is a lack of information in this area:
"The grant allows us to investigate an underexposed area, because heavy metals in produced water can rarely be detected via routine measurements, as they often occur in very low concentrations and are difficult to measure. In addition, the current legislation focuses mostly on non-dissolved oil residues in the water, but it is important to also look at solutes in the water, e.g. heavy metals, because they – even in low concentrations – can have a more harmful environmental impact than oil residues," says Karen Louise Feilberg.
Knowledge creates opportunities for action
For the VELUX FOUNDATION, the project is an important part of the programme "Combating marine pollution", as one of the foundation's three strategic initiatives in the marine environment. The Danish government has decided to phase out oil and gas extraction in the North Sea, but it will still be many years before the production platforms in the area are finally gone, and until then, more knowledge in the area is crucial:
"There are many indications that produced water is far more harmful to the marine environment than we have previously assumed, and if we are to combat marine pollution, we must work with all sources of pollution. This project creates the knowledge base for this," Charlotte Mogensen concludes.
