Environmental Report 2023

Waste is generally divided into hazardous and non-hazardous waste in accordance with current regulations and must be declared pursuant to national regulations and international guidelines.

In 2022, 20, 090 tons of non-hazardous waste were produced, which is a decrease from 21, 858 tons in 2021. Fig. 31 illustrates the breakdown of non-hazardous waste by various categories.

Fig. 31: Breakdown of non-hazardous waste from the offshore industry by various categories (in tons)

Offshore Norge and the NEA jointly introduced new codes in 2014 for hazardous waste from the industry. The aim of the update was to ensure correct waste treatment and declaration.

This update does however make it difficult to compare the various waste types with earlier statistics. A number of the categories have been split into several sub-categories, whilst others have been merged.

Fig. 32 illustrates that in 2022, 275, 738 tons of hazardous waste were sent ashore for treatment, compared to 309, 876 tons in 2021. 223, 153 tons of waste treated onshore were drilling-related. Vessel cleaning and oily waste accounted for 10, 558 and 11, 054 tons respectively.

The reason for the marked increase in oily waste from 2009 and several years thereafter is that previously, much of this waste would have been reinjected. Up to 2009, leaks from injection wells were detected on several fields and injection was stopped in 2009/2010. The oily waste was instead sent ashore for treatment. Methods for handling cuttings on these installations were based on slurrification to enable injection. Slurrification involves crushing the cuttings and adding water. It is not unusual for the volume of the cuttings to expand by four to ten times during the process. This practice continued and the cuttings were sent ashore as slurry, leading to a significant increase in drilling waste from certain fields.

Injection provides considerable environmental benefits and can be cost-efficient compared with final treatment onshore. The drilling of new injection wells has led to an increase in the volume of oily waste (see Chapter 4.1). For installations and fields not expected to reintroduce injection, an effort is made to reduce slurrification and subsequent waste.

Fig. 32: Volume of hazardous waste from offshore operations sent ashore

Rocks beneath the seabed contain varying amounts of radium and other radioactive isotopes. During oil and gas production, these naturally occurring radioactive substances accompany oil, gas and primarily water to the surface. These substances are often referred to as low-radioactive depositions.

On some fields, the sludge cleaned from oil-water separators can contain varying levels of measurable radioactivity. The concentration of these substances is measured by water and sludge analyses which are carried out by accredited laboratories. The waste is separated into and declared according to three categories; no enhanced concentrations, radioactivity levels lower than 10 becquerels per gram, and radioactivity levels higher than 10 becquerels per gram. Both radioactive categories are treated in accordance with the regulations issued by the Norwegian Radiation Protection Authority. The most radioactive material is sent to a designated landfill site in Gulen.

Fig. 33 illustrates the volumes (in tons) of radioactive waste sent for final disposal in the two categories. The waste containing radioactivity levels lower than 10 Bq/g varies due to fluctuating site capacity.

A total of 394 tons of low-level radioactive waste were sent ashore in 2022, marking a significant decrease from 1, 633 tons in 2021.

Fig. 33: Volumes of waste with naturally occurring radioactive material