When the first oilwell was drilled in 1859, the technology was not immediately aimed at avoiding pollution... But in almost two centuries since methods of extraction have improved very significantly in terms of spills and safety. Still accidents are occurring, such as blowouts and pipeline failures. In the case of offshore drilling, a well at the sea bottom may start leaking oil and gas. Such was the case in the Gulf of Mexico.
Oil pollution can occur during drilling, production, transport operations. It is clearly not in the interest of oil companies to cause pollution. Apart from loss of revenue, the consequences of the environmental damage can be enormous. But accidents happen. The most spectacular events are blowouts, where the drillers loose control over the flow from a well. A common cause of it is an unexpected abnormal high pressure in the layer being drilled. Normally, the weight of the drilling mud should counterbalance the formation pressure. But is this fails, a blowout may occur. A blowout preventor should automatically do its work by immediately closing off the well. If not, the famous firefighter Red Adair (1915-2004) and his crew could be called for help. For some time (1964), in Nigeria, I went to a drilling site to scan the wireline logs for abnormal pressures. In this way a safer mudweight could be chosen and the early warning would limit the chances of a blowout.
Some spills of crude have a geological origin: oil formed at depth migrates up a slope, but finds no trap. In that case , it reaches the surface and the crude will be attacked by occidation and bacteria. Occasionally fossil seeps, (fossilized pollution) are found within the stratigraphic sequence. Famous examples of seeps are asphalt lakes in Trinidad.
Nevertheless,a notorious example is the blowout of Bomu-2 near Port Harcourt (1970) and there are many more incidents. Most of industrial accidents have serious effects on a relatively small area around the site and it is hopefully of short duration. This contrast to the very large spills caused by oil theft. The latter damages are more widespread and continuous over years.
Fisheries suffer also from the oil film on the water surface, whilst people in the delta are so dependent on fish.
Methane leaks are not only of concern because of lost revenue and danger, but more so because CH4 is a potent greenhouse gas and responsible for 23% of the warming of the atmosphere. Amounts of methane are usually expressed as in Teragrams (tg), which means 1012 grams =106 tons = 1,000 kton. The IPCC use a conversion factor of 25 to convert CH4 into CO2-Equivalent for the longer term (100 years). Note that other abbreviations (EU) use "Million Metric Tons Carbon Dioxide Equivalent" (MMTCDE = Tg), in which the "MM" suggests a million... , can be confusing, but it makes clear that a ton = 1000 kilos.
In the short term (20 years) the "Global Warming Potential" could be as much as 86 times the CO2 effect, because of the half-life duration of methane (~9 years?), while decoposed into other greenhouse gases: water vapour, CO2 and Ozone, in the longer run. The long term conversion factor has recently been upgraded to 28! Here we have still used the (IPCC, AR4) factor of 25.
In this review only the exploration and production activities ("E&P") in oil and gas are considered, but they form an important part of amounts of industrial leaks. Other, larger anthropogenic sources are agriculture (rice, cattle) and coal mining. All anthropogenic sources amount to 50 - 60% of the total methane budget. Natural sources are lakes, rivers, wetlands, volcanos and the gas hydrates in the sea bottom. Amounts of methane are usually expressed as in Teragrams (tg), which means 1012 grams =106 tons = 1,000 kton. The global number is then an uncertain range of 737-567 Tg yearly global emission of methane. If (737) is converted to CO2 equivalent the amount becomes 18,425 Tg in terms of warming potential. The part attributed to fossil fuel production and use is about 20% of this, or ~3,600 Tg CO2 equivalent, but the "Global Carbon Project" uses 576 Tg and attributes half of the anthropgene emissions to fossil fuel production and use.
The contribution of E&P activities as percentage of total emissions per region is given By TNO as
We have only considered the yearly emissions. Fortunately, the methane is decomposed (518) and adsorbed in soils (38). But the emissions exceed the sinks by some 18 Tg/yr, hence the global atmospheric CH4 content is increasing at a rate of 5 or 6 ppb (parts per billion), or about 0.3%/year.
Since 2017 the Tropomi satellite measures the total atmosphere daily and measures methane concentration as well as that of other greenhouse gases.
Another, back of the envelope calculation of E&P methane emnission, is the assumption that the global amount is 1 or 1.5% of total gas production. For 2020 ~4,000 milliard cubic meters were produced, hence 1% is 40 milliard, or 28,680 kton (= 28.68 Tg). On this basis (assuming the 1%) the E&P contribution is in the range of 4 to 5% of total methane emissions.
The USGS report in 2018 that in the USA the E&P operations contribute 70% of the total industrial methane pollution on federal lands and that it amounts to 1,900 Tg Methane or 47.6 Tg/year CO2 equivalent, or 0.26% of the total global annual methane flow to the atmosphere. CO2 equivalent. Some improvement in practices has reduced the E&P contribution with 10.5% between 2005 and 2014 to the present figure.
The Russion E&P industry is partly rather old and environmental care was not one of the priorities in Soviet Russia.
EU satellites have detected major leaks from the Yamal pipeline. An estimate of 93 tons/hour means 0.791 Tg/year methane, with warming potential of ~20 Tg CO2 equivalent/year.
In nearby Turkmenistan another leak was observed in the Korpezhe field. It amounted to 142 kton/year or 0.142 Tg which would be 3.55 Tg CO2 equivalent/year.
Gazprom states that from its pipeline system, only 0.29% of the 679 milliard cubic meter transported is leaked. So the loss is around 2 milliard cu.meter. In weight that is 1.434 Tg methane, or 35.3 Tg CO2 equivalent/year.
The above estimates do not cover all operations in Russia, and neighbouring countries, so the total may be much larger. The above mentioned amounts add up to 2.345 (Tg) methane, compared to the global estimate of leakage by fossil fuel production and use of 111 Tg, hence not very much.
Despite much E&P activity in Norway, Germany, the Netherlands, UK, the contribution is not very large. Worth considering: in the dutch offshore, some gas is left to escape un-burned for the safety of sea birds. The dutch methane emissions from fossil fuels is estimated at 0.026 (Tg) or 3% of the total CH4 emissions in the Netherlands. Total gas production in the Netherlands before the limit on Groningen production was 60 milliard cu.m. In weight: 43,000 kton or 43 Tg. The emissions are then 0.06% of production, very different from the assumption by some that globally 1% of producion is leaked.
"Aan een boom, zo vol geladen,
mist men vijf zes pruimen niet."
["On a plumtree so fully laden
nobody will miss five or six plums"]
Hieronymus van Alphen (1746-1803), Childrens verses
Theft of crude oil or refined oil products
The theft of crude oil or refined petroleum products is widespread. Prime examples are Nigeria and Russia, but also product theft in Singapore and the Netherlands. Theft is on an industrial scale. The volumes stolen are so large that it has a serious impact on the Governments' revenue. But if the thieves are in collusion with the police, the army or some politicians, it is an uphill struggle to eradicate it. Ian Ralby, a marine expert of the Atlantic Council (2017), estimates the value of global oil (product and/or crude?) theft as 133 billion US$ per year. Romsom (2022) mentions an estimate of 5 - 7 % of the global market for crude oil and petroleum fuels.
Crude and oil product theft is on an industrial scale in Nigeria and began decades ago. Illegal pipelines are fitted to the official ones and production siphoned away at a rate that does not immediately rouse suspicion. However, several years ago an estimate of 40 to 60,000 b/d was made. Recently the National Nigerian Petroleum Company (NNPC) estimated that it had increased to 137,000 b/d and together with the products amounted to 200,000b/d. Adonu (2023) estimates recently even more: 400,000 b/d! That is the peak production of a giant oil field! However, the state agency NUPRC believes that 40% of the "theft" of crude is due to measurement errors....
The tapping, or simply blowing up part of a pipeline causes tremendous pollution in the Delta area. Certainly if open barges are filled to the brim with crude. Also many small, home-made refineries cause pollution as well as fires and fatalities. In a single instant of sabotage in 2018, 60 people were killed. Sadly, this is one of many similar disasters. The illegal gasoline or diesel is sold openly at illegal service stations, in competition with the official ones.
With up to 10% of NNPC production is getting into the wrong hands, one would ask why nothing or a little is undertaken to stop it. But widespread corruption, police, army, politicians are in the way.
The non-profit organisation "Stakeholder Democracy Network" (SDN) is focussed on correcting the link between the extractives industry and weak governance, currently specialising on the Niger Delta. It therefore requires an operating structure that mitigates the risks of operating in a conflicted region that has an unstable business environment and weak governance, underpinned by a weak rule of law.
Carlos Coelho reports in 2021 about Russia oil theft. He states: "Oil is the lifeblood of the Russian economy. It is also a commodity prized by criminal groups that illegally siphon off millions of tons a year from Russia’s pipelines to sell on the black market -- often with the complicity, or direct oversight, of corrupt law enforcement officials. A new investigation by RFE/RL's Russian Service details how this theft of the country’s key natural resource has flourished in its top oil-producing region -- the Khanty-Mansi Autonomous District -- and how those who blew the whistle have faced legal blowback. While the investigation focuses on one region, numerous sources confirm that the same schemes operate in other oil-producing regions across Russia. So how does this theft happen?"
Roslan Khasawneh, Fathin Ungku report (Reuter, 2018) that thieves,including ex-Shell employees, found way to steal 340,000 tonnes of gasoil from the Pulau Bekom refinery, possibly starting in 2014. It is valued at 150 million dollar. Several people have been arrested.
Ín Haaren, North Brabant provice, the The Rotterdam-Rhine pipeline (RRP) was sabotaged in 2020 to steal some 20 to 40,000 liters of nafta. Considerable pollution in a beatiful park was the result.
As the RRP is of major economic importance for Germany this event shows how vulnerable it is!