Operators are strongly encouraged to select wireline greases that are environmentally friendly to limit the environmental impact of accidental spillage and potential consequences when reporting any incidents to regulators. Choosing an environmentally friendly wireline fluid also makes it easier to apply for and obtain offshore usage permits in locations with stricter regulations and controls.
The North Sea’s HOCNF (Harmonised Offshore Chemical Notification Format) classifies products by their chemical formulations into colour categories. These colour bands determine how a product can be used and discharged in Norway’s offshore oil and gas industry and is determined by their impact on the marine environment. For a product discharge permit to be granted, the product must pass the biodegradability, aquatic toxicity and bioaccumulation tests specified by the Harmonised Offshore Chemical Notification Format. The product is then put into the green or yellow category. Products that do not meet this criterion and pose a risk to the environment are put into a red or black category, depending on their environmental impact.
As a signatory to The Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR Convention), the UK requires all chemicals used in connection with offshore petroleum activities to comply with OSPAR Decisions and Recommendations. The Offshore Chemical Notification Scheme (OCNS), operated in accordance with the requirements of the HOCNF, manages chemical use and discharge by the UK and Netherlands offshore petroleum industries. The scheme is regulated in the UK by BEIS (Depart for Business, Energy and Industrial Strategy) using scientific and environmental advice from the Centre for Environment, Fisheries and Aquaculture Science (CEFAS) and Marine Scotland. Chemical companies are required to submit a HOCNF, together with an up-to-date safety data sheet (SDS), to CEFAS to notify (or register) chemical products that will be used or discharged in the marine environment.
Wireline fluids are proven to be biodegradable through tests such as the Marine BODIS test or the OECD 306, which both use sea water as the medium. Sometimes the OECD 301B test which is a freshwater test is also used. A further criterion the lubricant must fulfil includes being demonstrably non-toxic towards fish, algae and sediment re-worker invertebrates if the preparation is denser than sea water. All components of the wireline formulation must be declared and the use of harmful or toxic additives is strictly controlled. An additional consideration is whether a wireline fluid is film-forming. Products with a lower density than sea water and with low biodegradability will tend to form persistent slicks over large areas of water, which is obviously undesirable. These slicks produce a noticeable sheen on the water, which is clearly visible, sometimes over many kilometres.
