The leak at Total’s North Sea gas well is only one of thousands of gas wells leaking worldwide. Indeed, it’s an issue the industry tries to keep quiet – although it’s known about it for a long time.
In 2000, eight thousand gas leaks were found in the Gulf of Mexico by the US Mineral Management Services department (p2 of the linked pdf).
Similarly, the Norwegian Petroleum Safety Authority found 18% of North Sea gas wells leaking in 2006.
Last year, Archer, a well service company, estimated worldwide that 19% of operating wells were shut down due to integrity issues (see p4 of the linked pdf).
And another gas services company – Schlumberger – noted 60% of offshore gas wells leaked after 30 years (see p2 of the linked pdf).
At issue is what the industry calls ‘sustained casing pressure’ (SCP) or ‘sustained annular pressure’ (SAP). This means that gas has leaked from the central conduit running to the surface – to an unknown fate.
Although specific details of Total’s gas leak are unclear, it appears engineers discovered SCP in the well late in March. The UK’s Daily Telegraph reported “Workers spotted changes to the pressure in its outer casing weeks ago” . This pressure built up – and eventually burst free – at the top of the well.
The huge number of leaking wells is a structural rather than regulatory problem. That’s because the industry is unable to build wells that don’t leak. In almost every area of the oil and gas industry you find one thing is constant – leaks.
Professor Tony Ingraffea of Cornell University has studied gas wells for 30 years. You can see his video of why gas wells leak here:
Indeed, leaking wells is not limited to the conventional gas industry. A study of a coal bed methane wells in Australia recently revealed 44% of wells leaking.
And both oil and gas wells leaking were found by a Canadian study in 2009 which showed more than 17,600 oil and gas wells leaking nationwide.
In 1992 the US EPA estimated that of 1.2 million abandoned oil and gas wells in the US, 200,000 were leaking, a 16.7% failure rate.
The hydraulic fracturing industry is insistent that its wells are somehow immune from this global phenomena. They deny academic reports such as Duke University’s, and US government reports such as the EPA that find gas and chemicals associated with fracking in water nearby.
That’s because they – just as the rest of the gas industry – are in denial about a central fact: gas wells leak.
Norway: In 2006 the Norwegian Petroleum Safety Authority sampled 406 of 2,682 wells. 18% of wells had well integrity failures or issues. 7% were completely shut in owing to integrity issues.
Gulf of Mexico: SCP in over 11,000 casing strings in over 8,000 wells, according to the US Mineral Management Services. Later, in 2004, the MMS reported 6,650 of 14,927 Gulf of Mexico wells had SAP.
Australia: In 2011 the Quensland Mines Department found 26 out of 56 Coal Bed Methane wells leaking at the Tara gas field – 44%
North Sea: In 2009, the Society of Petroleum Engineers’ forum ‘North Sea Well Integrity Challenges’ surveyed 100 participants. These indicated that an average of 1,600 out of 4,700 North Sea wells had at least one anomaly.