Fracking by stealth continues despite the temporary suspension

Brockham Oil Watch
Tuesday, 13th April 2021

Brockham Oil Watch share new research into 'acid stimulation' and fracking by stealth, where fracking is continuing to take place despite England's temporary suspension.

A new research article 'Acid stimulation: Fracking by stealth continues despite the moratorium in England' was published in the international peer-reviewed journal Energy Policy

The article is a fuller, updated policy discussion of our previous briefing paper on acidisation. It is co-authored by Adriana Zalucka of Brockham Oil Watch, Alice Goodenough of Harrison Grant Solicitors and David Smythe, Emeritus Professor at the University of Glasgow. The article can be accessed and downloaded until 27 May here, after which the accepted manuscript text version will remain available on our website.

The article’s key highlights are: 

  • The legal definition of fracking is too limited in scope.

  • Acid stimulation is excluded despite the environmental harm involved.

  • Regulators have failed to grapple with ambiguities and inconsistencies.

  • The 2019 moratorium is ambiguous and fails to remedy the issue for many affected communities.

  • Our new definition of unconventional hydrocarbon extraction is scientifically robust.

Our definition and proposals for implementation will close the existing loophole in the current phase of hydrocarbon exploration and production in England, which targets mainly unconventional oil and gas, but which the operators are pursuing under the guise of conventional activities.

To meet climate change concerns, the 2019 moratorium should be converted into a ban. In the interim, we argue that, in order to comply with the government's policy of ensuring safe and sustainable operations, the moratorium should be extended to all well stimulation treatments for unconventional hydrocarbon extraction, including acid stimulation.

Acid stimulation

Acid stimulation can be described as a type of fracking performed on limestone or sandstone-rich shale that dissolves the rock enlarging or creating new fractures.

Acid stimulation, which the industry sometimes refers to as an “acid squeeze”, includes matrix acidising (fluid pumped below formation fracture pressure) and acid fracking (fluid pumped above formation fracture pressure). It uses less water than high volume hydraulic fracturing, but because it’s an acid-based method, the concentrations of acid and other chemicals are higher. In addition to high strength hydrochloric or hydrofluoric acids (used on limestone and sandstone respectively), other chemicals are added, similar to those used in the hydraulic fracturing process.

Unlike hydraulic fracturing, acid stimulation has not been researched widely, but the available studies, as well as common sense, suggest that the expected risks of this process are the same as of hydraulic fracturing: risk of pollution to groundwater, surface water and air, stress on water supplies, toxic and potentially radioactive wastewater, and industrialisation from drilling multiple wells in close intervals, both in space and time.

Unfortunately, acid stimulation, like hydraulic fracturing that doesn’t meet the arbitrary thresholds of injected fluid volume set out in the Infrastructure Act 2015, is exempt from the Government definition of associated hydraulic fracturing, and from the regulations introduced by the IA2015.

Threatened communities

Communities that are still threatened by fracking include:

  • Brockham, Horse Hill & Dunsfold in Surrey
  • Balcombe & Bradford Bridge in West Sussex
  • Arreton on the Isle of Wight
  • Ellesmere Port and Ince Marshes in Cheshire
  • Wressle in Lincolnshire
  • West Newton in East Yorkshire
  • Preston New Road in Lancashire (Cuadrilla surrendered environmental permit for key operations in Dec 2020)
  • Harthill and Woodsetts in South Yorkshire
  • Altcar Moss near Formby, Lancashire (withdrawn!)
  • possibly Third Energy’s sites in North Yorkshire, who were going to frack Kirby Misperton, but since sold the business and are now focusing on conventional sites (raising suspicions about what extraction methods those so-called conventional sites will require)
  • Springs Road, Misson, Nottinghamshire
  • Fermanagh in Northern Ireland 
  • licenses on the coast of Somerset.

About Brockham Oil Watch: Brockham Oil Watch (BOW) is a non-political group of local residents concerned about the threat of unconventional hydrocarbon extraction from the Kimmeridge Clay Formation (or other unconventional reservoirs) at Brockham, and gaps in the current legislative/regulatory framework. For more information visit

About Professor Smythe:  David K. Smythe is Emeritus Professor of Geophysics at the University of Glasgow. He took early retirement from the Chair of Geophysics in 1998 when the Department of Geology & Applied Geology was closed. He lives in France. His main current research interests are fracking, nuclear waste disposal, and nuclear accidents. For more information visit:

About Harrison Grant Solicitors:  Harrison Grant provides experience and expertise in public law, planning and environmental law (including international law), human rights and advice on governance for charities and campaign groups. Noted for its role in high profile cases, it is recognised as a leading law firm of leading lawyers. For more information visit