People are invited to comment on an application by IGas to dispose of radioactive waste at its Singleton oil site in West Sussex.
The company is seeking an environmental permit to reinject water produced from oil and gas sites in the Weald. The water would contain naturally-occurring radioactive material, known as NORM.
The application is part of an exercise to bring older oil and gas sites under environmental regulations first introduced in 2013.
IGas said reinjection of produced water had previously been carried out at Singleton. A spokesperson said:
“There has been no change in the composition of the produced water at Singleton, this is indeed just part of the re-permitting exercise. The regulator is just permitting the activity differently.”
In the application for a radioactive substances permit, the company said it was seeking consent for:
“receiving and reinjecting back to the oil producing reservoir at the Singleton Oilfield, produced waters containing NORM levels above the out of scope limits resulting from the production of oil and gas at the Singleton oilfield, other IGas onshore oilfields in southern England and produced water from the Holybourne Oil Storage Terminal.”
“Above the out of scope limits” means the level of radioactivity is high enough to be covered by environmental legislation.
The application said:
“The Singleton wellsite currently reinjects produced water separated out from on site oil production, and occasional low volume imports of produced water from the Holybourne Oil Storage Terminal [in Hampshire] which has no reinjection capability. It can also act as a contingency injection site for other IGas oilfields in the south of England should their injection well/s go off line for any reason.”
A public consultation on the application runs until 6 February 2020.
Singleton, in the South Downs north of Chichester, was first drilled in 1988 and began oil production in 1990.
The site was taken over by IGas from Providence Resources in 2013. It was IGas’s second most productive site in 2018, the most recent year for which full figures are available.
DrillOrDrop reported that Singleton produced 23,786m3 of oil in 2018. This was 2.5% of the UK’s onshore total oil production. More than 80% was from one site, Wytch Farm in Dorset.
Opponents of onshore oil and gas operations have concerns about reinjection because it has been linked in the United States to seismic activity. The Chichester area is heavily faulted and has been the centre of numerous small natural earth tremors, dating back to the 18th century.
But disposal by reinjection is a key saving for onshore oil companies. One industry boss told DrillOrDrop the salinity of produced water was so high that it was “almost impossibly expensive” to treat. As a result, he said, the water was taken by tanker to an incinerator.
According to the Singleton application, IGas is seeking permission to reinject up to 17,000m3 of produced water a year, with a monthly limit of 2,500m3. There is no information in the application about whether this is more or less than had previously been injected.
The produced water would initially be stored in tanks, the application said. The radioactivity level would be checked by annual lab analysis.
The application documents, available online, do not include the usual non-technical summary of the proposal. They also do not include a site boundary map or a supplementary document mentioned in the application forms.
The latest Environment Agency guidance, issued on 14 February 2019 said oil and gas companies could reinject produced water into geological formations from which hydrocarbons have been extracted to encourage the further production of hydrocarbons.
Produced water could also be reinjected into the geological formations that for natural reasons the Environment Agency had determined as “permanently unsuitable for other uses”.
A radioactive substances permit was not needed if the produced water was generated and reinjected at the same site. This was because the regulations did not regard produced water as waste, regardless of the NORM concentration, if it was supporting production.
A radioactive substances permit would be needed if produced water was reinjected at a different site from where it was generated and the NORM concentration was above out of scope levels. In this case, the produced water was considered to be radioactive waste.
Where operators wanted to dispose of water by reinjection (as opposed to reinject to support production) they would need a groundwater activity permit. If the NORM concentration was above out of scope levels, they would also need a radioactive substances permit.
Produced water is different from flowback fluid from fracking or well stimulation operations. The guidance said flowback fluid could not be reinjected into any geological formation for disposal, whatever the NORM concentration.