Fluid thinking

With Canadian environmental regulators tightening their monitoring and control of fluids used offshore, Castrol's Jason Vallier and K+D Pratt's Andrew Bell review existing guidelines elsewhere and the implications for Canada's E&P sector.

The Canadian government recently began asking offshore permit holders for OSPAR (Oslo & Paris Convention) information on the environmental specifications of thruster fluids.

Meanwhile, the Canada-Newfoundland & Labrador Offshore Petroleum Board has introduced more regular rig inspections (once every three weeks), seeking to enforce existing rules more strictly. These audits will assess whether operators have selected products that minimise environmental impact.

While not explicitly expressed in selection criteria, Canada's environmental guidelines recognise the principle of ‘substitution', whereby technically feasible substitutes should be found for potentially environmentally damaging chemicals in products.

Canada's Offshore Chemical Selection Guidelines (OCSG) provide a framework for chemical selection which minimises the potential for environmental impacts from the discharge of chemicals used in offshore drilling and production operations in Canada.

The guidelines are issued by the National Energy Board, the Canada- Newfoundland & Labrador Offshore Petroleum Board and the Canada-Nova Scotia Offshore Petroleum Board. They apply to all chemicals intended to be discharged into the marine environment. Operators are required to select chemicals with the least environmental risk.

The guidelines apply to a large range of lubricants and hydraulic fluids used in topside and subsea applications, including thrusters, subsea and surface production control systems, blowout preventers, subsea isolation valves, crane and drilling system hydraulics, mooring winch gears and jacking legs.

The OCSG uses the UK Offshore Chemical Notification Scheme (OCNS) ratings for assessing whether a product is acceptable for use and discharge offshore. Products with an OCNS rating of C, D or E are acceptable.

Products with an OCNS rating of A and B are only acceptable with a robust justification for use.

OSPAR is the mechanism by which 15 governments of the western coasts and catchments of Europe, together with the European Union, cooperate to protect the marine environment of the Northeast Atlantic. It started in 1972 with the Oslo Convention against dumping. It was broadened to cover land-based sources and the offshore industry by the Paris Convention of 1974.

These two conventions were unified, up-dated and extended by the 1992 OSPAR Convention.

Torrey Canyon trigger

The grounding of Torrey Canyon in 1967, and the subsequent release of 117,000t of oil, proved to be a pivotal point for international cooperation to combat marine pollution in the Northeast Atlantic. It ultimately stimulated the signature, in 1969, of the Agreement for Cooperation in Dealing with Pollution of the North Sea by Oil (the ‘Bonn Agreement').

Next came the agreement and signature of the Convention for the Prevention of Marine Pollution by Dumping from Ships & Aircraft (the ‘Oslo Convention').

On 16 July 1971, the Dutch ship Stella Maris, having sailed from Rotterdam to dump chlorinated waste in the North Sea, was obliged to return to port without carrying out her mission. Just eight months later, the Oslo Convention was signed, and it entered into force in 1974. In 1978 a similar document came into force covering marine pollution by discharges of dangerous substances from land-based sources, watercourses or pipelines (the ‘Paris Convention'). In the UK, there are two stages to the environmental classification of products for use offshore. A product must first be assessed according to the OSPAR Harmonised Pre- Screening Scheme and then by the UK OCNS: l the OSPAR Harmonised Pre-Screening Scheme determines whether the product contains any substitutable components which must then be replaced by more environmentally responsible alternatives. Substitution warnings are applied to the whole product; l OCNS is a hazard assessment system that assigns for a product either a colour banding, using the CHARM model (Chemical Hazard Assessment & Risk Management), or an OCNS group (for products that cannot be assessed using the CHARM model, eg subsea hydraulic control fluids). Subsea hydraulic control fluids are therefore assigned an OCNS group from A to E, A being the greatest environmental hazard and E being the least. Both stages use the OSPAR required data sets of biodegradation, bioaccumulation and toxicity of each component used in the product to assess its environmental impact. The OSPAR guidelines use three primary criteria collectively to determine the level of impact:

  • marine toxicity;
  • marine biodegradation; and
  • bioaccumulation.

Operators are thus expected to select products using the OCSG guidelines to ensure that they have minimal marine environmental impact. OE


Jason Vallier is Castrol Offshore's North American distribution manager, based in the Greater Atlanta area. He has been with Castrol and previously Air BP for 15 years and before that spent seven years with the US Coast Guard as a machinery technician.



Andrew Bell is president of K&D Pratt, an Atlantic Canada industrial supply company that serves as Castrol Offshore's Canadian distributor.

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