Oil and gas industry waste

There are over 600 offshore oil and gas installations in the North Sea, 470 of which are in British waters. Each can be at least as big as ‘Big Ben’ and combined produce millions of tonnes of waste, mostly in the form of ‘produced’ wastewater, a by-product of the oil and gas extraction process.

Associated with these activities, you will also find millions of tonnes of drill cuttings (bits of broken rock and soil from drilling), lesser quantities of drilling fluids, spent chemicals, and more.

Additionally, more than 10,000 km of pipelines and 5,000 ageing wells are gradually being decommissioned after fulfilling their lifespan, and the associated wastes of oil and gas transmission and transport (tank sludge, radioactive scale, subsea mattresses, metal scrap, etc.).

Finally, hundreds of commercial businesses in sectors like hospitality, food and beverage, and events indirectly support the industry’s operations.

Here is a list of sections that will help you navigate this article:

Notable oil & gas wastes
Oil & gas waste regulations
Oil & gas waste management technology
Environmental impacts of oil & gas waste
Commercial waste disposal in the oil & gas sector

Oil and gas waste highlights

Water and drill cuttings

The vast majority (>95% of 120 million tonnes) of the annual oil & gas waste comprises ‘produced’ water and drill cuttings from offshore production and exploration wells.

Source: Ballpark estimation using statista & Njuguna, et al. 2020

Re-injection into reservoirs

Most of the ‘produced’ water (~70-80%) is reinjected into wells to pressurise the reservoir for enhanced recovery, leaving only a proportion for reuse, recycling or treatment and disposal at the surface.

Source: Ballpark estimation using statista, statista & Njuguna, et al. 2020

Offshore disposal

Some of the drill cuttings, drilling fluid, and ‘produced’ water are treated offshore and disposed of in the ocean. The historical environmental effects of this have been atrocious, but recent regulations have significantly improved this.

Source: Njuguna, et al. 2020

Onshore management

The rest of the waste (~120,000 tonnes per year), like spent chemicals, oils, scrap metals from decommissioning, tank sludge and radioactive scale, is sent onshore via pipelines, barges or tankers for special treatment and reuse, recycling or disposal.

Source: statista & Njuguna, et al. 2020

Reducing volumes

The total amount of oil & gas waste decreases year-on-year as the UK winds down on fossil fuels.

Source: statista, offshore-mag.

Hazardous & radioactive waste

A small portion of oil & gas wastes (~1%) are hazardous, including waste containing chemicals, radioactive materials, and other substances that pose environmental or health risks.

Source: statista

Notable oil and gas waste

Hundreds, if not thousands, of wastes are associated with the oil & gas industry. Here are the most notable types, in order of their estimated yearly tonnage (we assessed several sources to make ballpark estimation of these waste quantities):

Waste Type	Yearly tonnage	Origin	Waste management strategy
‘Produced’ water	100s of millions of tonnes	A byproduct of oil and gas production. It’s a mixture of geological and injection water with salts, hydrocarbons, chemicals, heavy metals, radioactive minerals, etc.	The vast majority is treated and re-injected back into wells to pressurise the reservoir (re-use) Any excess is treated to meet regulations and discharged at sea or transported in pipeline or tankers onto onshore facilities for treatment using advanced technologies.
Drill cuttings	~1-2 million tonnes	Any drilling operation has to break through rock and soil. The remaining micrometre fragments are the drill cuttings which are carried to the surface by ‘produced’ water during drilling.	The drill cuttings are separated from the ‘produced’ water using advanced technologies and treated. Depending on their composition and level of contaminants, they are disposed of at sea or transported onshore to be landfilled or re-used as construction material, landfill cover, etc.
Hazardous solids, liquids, oils, chemicals, additives, tank sludges	~80,000 tonnes	From all processes, both offshore and onshore.	Transported onshore for special treatment and reuse, recycling or disposal. Follows hazardous and special waste regulations.
Scrap metal	~22,000 tonnes	Decommissioned equipment, piping, infrastructure.	Scrap metal is typically sorted, cleaned, and sent to recycling facilities where it can be melted down and repurposed into new products. In some cases, it can be salvaged and reused or must be disposed of due to contamination.
Other (Drums, containers, general waste, etc)	~10,000 tonnes	The rest of the waste	Various recycling and disposal methods.
Radioactive waste	~1,000 tonnes	Accumulation of naturally-occurring radioactive minerals (NORM) in pipes, equipment and other wastes.	Transported onshore for special treatment and reuse, recycling or disposal under radioactive waste regulations.

Oil and gas waste operations

Unlike smaller commercial properties in the UK, waste management in the oil industry is complex, mirroring its complex offshore and onshore operations. As such, many specialist commercial waste disposal operators are necessary to complete its various unique tasks, including:

Decommissioning and recycling of metal infrastructure like production rigs, wells, vessels, etc.
Marine waste transportation in tankers and barges for onshore processing.
Handling, processing and disposal of radioactive waste.
Waste exports (banned for disposal, allowed for incineration and recycling)

Waste minimisation in oil and gas

Waste minimisation in the oil and gas sector has existed since its inception.

For example, re-injection of ‘produced’ water and drill cuttings back into deep underground reservoirs is a form of waste minimisation that serves the purpose of pressurising reservoirs for enhanced recovery (forcing out the hardest-to-extract oil and gas).

Also, the decommissioning of North Sea oil & gas assets has yielded thousands of tonnes of metal recycled by onshore facilities in the UK.

So, while the industry’s reputation is prioritising profits before environmental responsibility, doing so has indirectly led to the implementation of many circular economy mechanisms and the building of recycling infrastructure in the UK.

💡 Did you know? The forecasted cost of decommissioning offshore infrastructure has been reduced by 25% since 2017, partly due to more efficient waste management and decommissioning practices of oil & gas assets.

Oil and gas waste regulations

UK commercial waste regulations and their devolved Scottish, Welsh, and Northern Irish equivalents apply to oil and gas waste only once it reaches onshore, past the low tide mark.

This means that the waste generated offshore (the vast majority!) is subject to different regulations while it is at sea. Also, since it includes special and radioactive wastes, it is subject to additional, more stringent regulations than your typical corner shop.

Additional regulations, regulators and authorities

Here are some extra regulations that apply to oil & gas waste:

Additionally, the following authorities have regulatory power over waste management operations at sea:

💡 The Offshore-Onshore boundary: The low-tide mark is the official boundary separating the jurisdictions of offshore (e.g. OPRED, OSDR) and onshore (e.g. SEPA, EA) authorities.

Oil and Gas waste management technology

The oil and gas industry is renowned for having the capital to develop cutting-edge technologies to maximise efficiency and profits. With environmental pressures growing, they are deploying their financial firepower to improve waste management technologies to handle, treat, and dispose of problematic, difficult-to-recycle waste.

Here are some examples of existing processes:

Separating drill cuttings

Solids control equipment

Shale shakers, de-sanders, de-silters, and centrifuges are used to separate drill cuttings (i.e. rock and soil fragments) and other solids from drilling fluids. This equipment helps reduce the volume of waste and allows for the reuse of drilling fluids, which would otherwise become disposable chemical waste that requires treatment.

Thermal desorption units

These units use heat to separate hydrocarbons from drill cuttings. The process recovers reusable oil and produces dry, non-hazardous solids that can be disposed of more easily in landfills onshore or reused in industries like construction. The units are only improving as they incorporate AI and robotics.

Reinjection

Technology that grinds drill cuttings into fine particles and injects them back into the subsurface formations with ‘produced’ water. This method reduces the need for surface disposal and minimises environmental impact.

Hazardous waste processing

Bioremediation

Microorganisms are used to break down or degrade hazardous substances in contaminated waste, such as tank sludge, spent chemicals, oily waters, etc. This method is passive, emits few emissions, and requires little energy, making it ideal.

Advanced water treatments

These include membrane filtration, reverse osmosis, and evaporation systems that are used to treat produced water and other wastewater streams. Depending on the level of treatment, the treated water can be directly reused in offshore operations or safely discharged into the sea with minimal environmental impact.

Waste-to-Energy technology

Some facilities convert waste into energy through incineration, gasification, or pyrolysis. This reduces the volume of waste and generates energy that can be used directly in offshore operations or sold to the grid when onshore.

💡 Reduced landfill waste: The total quantity of waste sent to landfills from offshore oil and gas installations decreased by 16% from 2018 to 2019, showing the industry following the UK-wide preference for waste incineration.

Radioactive waste processing

Technologies for managing Naturally Occurring Radioactive Material (NORM) include descaling facilities, encapsulation, and specialised disposal methods to ensure the safe handling and disposal of radioactive waste. These are extremely high-tech and specialised, and much of their development has been funded by oil and gas money.

💡 Recycling technologies: Read our article on commercial recycling technologies to understand what may be incorporated into oil and gas waste management.

Environmental impacts of oil and gas waste

Oil and gas waste can have significant environmental impacts if not properly managed, which is why the industry is subject to strict regulations and oversight. The sector has continuously improved its environmental performance, but there are still areas for improvement.

Here are three environmental impacts of oil & gas waste:

Seabed and soil contamination

Improper disposal of drilling muds and cuttings can lead to soil contamination onshore or seabed contamination offshore. This can affect ecosystems and their organisms and lead to groundwater contamination.

Water pollution

Discharge of ‘produced’ water, which contains a mix of hydrocarbons, salts, and other chemicals, can pollute seawater, surface water and groundwater. Spills and leaks from storage tanks, pipelines, and other equipment can also lead to water contamination.

Radiological risk

Naturally Occurring Radioactive Material (NORM) present in oil and gas waste poses a radiological risk to workers, the public, and the environment. Proper handling, treatment, and disposal of NORM waste are essential to mitigate this risk.

Historical impacts

When the oil and gas industry was established in the North Sea in 1964, the environmental impacts of its waste were poorly understood. It is only more recently that studies have shed light to the issues that have arisen from 60 years of oil & gas extraction.

Drill-cutting deposits from past operations have been found in piles as high as 30 – 60 metres in the floor bed, and in some cases, mineral oil has been found as far as 4km away from offshore platforms (Source: Njuguna, et al. 2020)

Spent drilling fluid used to be discharged into landfills or the ocean without any treatment, causing serious environmental pollution. This gradually changed, but the marked impact was seen when the EU Waste Framework Directive (WFD) was implemented in 2008, forcing companies to treat the waste before disposal definitively.

While a range of treatment and disposal options are currently in practice, there is still a need to improve and intensify recycling and treatment efforts. Even though we’re past peak production of oil & gas in the North Sea, many decades of fossil fuel extraction remain.

Commercial waste disposal in the oil and gas sector

Thousands of small and medium businesses provide essential services to the oil and gas industry, especially in areas with a significant presence, such as Aberdeen, Newcastle, Hull, and London.

These include businesses in the entertainment and retail sectors, providing services like restoration, equipment supplies and warehouses, just to name a few.

These businesses require commercial waste collection services to meet their recycling and disposal needs, and the best way to get the best price and services is to compare commercial waste quotes.