Cuadrilla reveals details of tests on Balcombe oil well

Wednesday 21st August 2013. Balcombe South East England, UK. Cua

Cuadrilla’s Balcombe site in 2013. Photo: David Burr

A month-long public consultation began today on regulation of Cuadrilla’s plans to test its exploratory oil well at Balcombe in West Sussex.

The company is applying to the Environment Agency to make changes to its permit for the well, drilled during anti-fracking protests in July and August 2013.

The application, running to nearly 100 pages, includes details of how the company will test the rate that oil flows. This will help to establish whether the well would be commercially viable.

As part of the test, the company said it planned to pump a 10% solution of hydrochloric acid round the well to clean the bore and the rocks surrounding it. There were no plans for hydraulic or acid fracturing, it said.

Cuadrilla estimated the tests could produce up to 35,000m3 of waste gas, which would be burned in a 45ft (13.7m) high flare. The tests were also expected to result in 82m3 of spent dilute hydrochloric acid and produced water from the well, which would be removed by tanker.

The application includes information about a new flare and monitoring arrangements for air and water quality during the well test. But some details have been removed from the application under a confidentiality option open to the company.

There is also a request to remove two waste products from the permit: drilling mud and spent acid and produced water, referred to as “salty water”. The company said it had “no intention to leave any fluid in the formation”.

The Balcombe well has been suspended since September 2013. West Sussex County Council granted planning permission in May 2014 for flow testing, abandonment and restoration. To comply with this permission, Cuadrilla must begin work by 2 May 2017 and complete operations within six months.

Kathryn McWhirter, of the No Fracking in Balcombe Society, said:

“We believe Cuadrilla are simply tidying up their paperwork before probably applying for an extension to their planning permission, and then we expect them to sell on the licence (PEDL) to another operator, probably UKOG.

“They say the impact of emissions from their new flare will be minimal. We disagree. The flare is one of the most concerning aspects of this development for the village.

“They have made a few feeble additions to their monitoring proposals, which remain totally inadequate.

“They seem to want to remove the ‘salt water’ flowback and produced water from the scrutiny it deserves under the minerals waste permit. We believe this waste should be carefully monitored.”

DrillOrDrop asked Cuadrilla when it planned to begin flow testing at Balcombe. This post will be updated with any response.

The deadline for comments is 25 April 2017. Link to consultation page.


The following information (except where indicated) has been extracted from the permit application.

Duration of flow test

3-7 days followed by 10-20 days of shut-in of the well

Flow test stages

Stage 1: Fluid currently in the well would be removed to a tank.

Stage 2: Approx 20m3 of 10% dilution of hydrochloric acid would be circulated in the well in a matrix acid wash. This would remove drilling mud debris from the horizontal section of the wellbore and clean the rocks surround it, the document said. It added that there would be “minimal” penetration of acid into the surrounding rocks – estimated at less than 6 inches – and the pressure used in the operation would not cause fractures.

Stage 3: Well flushed with nitrogen gas to remove liquids.

The company’s planning application said fluids and gases would then pumped from the well for about a week, 24-hours a day. Fluids would be stored in tanks and gases piped to the flare.

Flare and waste gases

The document said:

“This is an oil exploratory operation and we do not expect to encounter gas (although the possibility cannot be ruled out entirely)”.

However, it estimates, as a worst-case scenario, the volume of surplus gas from the well would be 35,000m3 for the duration of the well test.

Cuadrilla said it had developed a flare that would burn these gases at 800 degrees C, converting 98% of methane to carbon dioxide, carbon monomers and waste. If this standard were not achieved, the well would be temporarily shut-in to prevent the flow of gases, it said.

The application added:

“unabated releases of natural gas to atmosphere will be avoided”.

According to the document, the flare has a 15ft high stand pipe and a 30ft high chimney. Air vents had been cut into the chimney. This allows air to be drawn into system during flaring for a more complete burning of gas.

“The chimney suppresses both the noise levels and the light emissions. It also significantly reduces the heat given off by the flame.”

“All gas is trapped in the 30ft chimney and is subjected to a longer burn path, thus preventing any stray natural gas from escaping off to the sides before reaching the flame.”

Before the flow test begins, Cuadrilla said the flare would be hard-engineered to restrict it burning more than 10 tonnes of gas a day. The company would also carry out a review to ensure that it met Best Available Techniques.

Other wastes

  • Well suspension fluid: assessed as hazardous because of the potential presence of crude oil
  • Cement: assessed as non-hazardous; estimated volume 10m3; sent for off-site recycling
  • Nitrogen: assessed as inert and to be vented from the well
  • Spent hydrochloric acid and produced water: assessed as non-hazardous; estimated volume 82m3; sent by tanker off-site for recycling

Risks and monitoring

A risk assessment in the application concluded there would be:

“No significant risk from mud, odour, noise/vibration, waste, air quality and emissions with global warming potential, or accidents at the site”.

It identified measures to reduce risks. These included:

  • “Use of Environment Agency authorised haulage/delivery companies”
  • “Visual inspection of tanks during site daily HSE tours”
  • “Wellhead, pipes and flare stack designed to prevent fugitive gas emissions”
  • “24-hour supervision of pipes and flare during flow testing”
  • “Flare designed for complete combustion at temperature in line with BAT [Best Available Techniques] requirements”
  • “Ability to shut in the well in the unlikely event of an inefficient burn”
  • Temperature monitoring and recording of flare at base and tip. Continuous monitoring
  • Testing of pipework and joints before flow testing

Ground and surface water

The risk to ground and surface water was regarded as low. But the application said metals, hydrocarbons and dissolved methane, carbon dioxide and oxygen would be monitored onsite “to maintain surveillance on groundwater quality”. Metals and hydrocarbons would be monitored onsite for the impact on surface water quality.

Three single samples would be taken at the start, middle and final day of the well test for ground and surface water monitoring.

Air quality and emissions

The application said air quality would be monitored during the well testing programme, with checks at four locations for nitrogen dioxide, sulphur dioxide, hydrogen sulphide, methane, VOCs (volatile organic carbons) and BTEX (benzene, toluene, ethylbenzene and xylene – compounds in crude oil).

Fugitive air emissions were expected to be “very minor” and a low environmental risk. Methane would be monitored twice during the well test.

Noise and vibration

The documents said noise would be maintained at the levels set in the planning permission. The maximum levels were: 55dB from 7am-7pm Monday to Friday and 8am-1pm on Saturday; background levels 7pm-10pm; and 42dB at night (10pm-7am).

Flaring was likely to be a source of noise, the document said. But it said flaring would last for about a week, would not be near homes and the site was screened by trees. Noise monitoring would be “undertaken at pre-determined locations and close to sensitive receptors”. Complaints would be investigated and monitoring may lead to additional mitigation, the document said.


According to the document, the risk of spills was low. But nearby water features would be sampled once a week to identify any contaminants from the site. The quantity of produced water and spent hydrochloric acid would be recorded and sampled. The operations were not expected to produce smells.


The junction of the site entrance and the road would be inspected daily to “ensure potential mud deposits from road tankers does not become a problem”.


Link to permit application consultation

Link to planning application details

DrillOrDrop page for Balcombe with key details, links and timeline

44 replies »

  1. High on the Google search:

    As with other toxic chemicals, health problems from oil may be difficult to prove because they take a long time to affect people. But most people who live and work near oil drilling sites and refineries are familiar with the pollution of air and water from oil. Drilling for oil, refining it, and burning oil as fuel all lead to many serious health problems, such as the ones listed below and those discussed in more detail on the pages that follow:

    blurred vision and other eye problems
    headaches, hallucinations, euphoria (sudden feelings of happiness), tiredness, slurred speech, brain damage, coma
    convulsions and unusual deaths
    nose sores and nose bleeds
    ear infections
    asthma, bronchitis, pneumonia and other respiratory diseases
    lung and throat infections and cancers
    increased risk of TB (tuberculosis)
    heart attacks
    digestive problems, including vomiting, ulcers, and stomach cancer
    damage to liver, kidneys, and bone marrow
    menstrual problems, miscarriages, stillbirths, and birth defects
    skin rashes, fungus, and cancers

    Oil causes reproductive health problems
    Breathing fumes or swallowing food or liquids contaminated by oil and gas causes reproductive health problems such as irregular bleeding cycles, miscarriages, stillbirths, and birth defects. These problems may have early warning signs such as abdominal pain or irregular bleeding.

    Oil causes cancer
    Regular contact with oil and gas causes cancer. Children living near oil refineries are much more likely to get cancer of the blood (leukemia) than those who live farther away. People living in areas where oil is drilled are much more likely to develop cancers of the stomach, bladder, and lungs than people living in other places. Workers in oil refineries have a high risk of cancer of the lip, stomach, liver, pancreas, connective tissue, prostate, eye, brain, and blood.

    When Texaco began drilling for oil in Ecuador, cancer was not known in the region. Forty years later, it is one of the region’s worst health problems. In 2 of the most heavily exploited oil regions of the Amazon, the community health workers did a survey of 80 communities and found high rates of cancer, especially cancer of the stomach, bladder, and mouth.


    • You’re using as your source an article that starts by saying “When companies first start looking for oil, forests are cut down and homes are destroyed. Roads are built, and streams and rivers are blocked up. The search for for oil often involves a series of explosions set off to help oil companies know what is underground. This is called seismic testing. Seismic testing damages homes, wildlife, and the land.”
      This is fiction.

  2. Unfortunately that is what oil companies do in places where they can get away with it. You ask about ill health and oil to workers. ‘The British Journal of Industrial Medicine1981 “An Epidemiological study of eight oil refineries in Britain’ (Rushton and Alderson)'”The carcinogenic properties of mineral oil have been well documented”….A study of workers between 1950 and 1975: “Raised mortality patterns were found in several refineries for cancers of the oesophagus, stomach, intestines, and rectum, although no location was consistently high for all these causes of death….In general, mortality from these causes increased as length of service and interval from starting work increased. There were also significantly more observed deaths than expected from cancer of the nasal cavaties and sinus and melanoma. ”

    There is plenty of evidence that oil is not healthy or living near flares. Remember if this industry gets going in the Weald it will not be in the same style as Singleton and Horndean. These are conventional wells where the oil is easy to access. Horse Hill, Balcombe and the new applications coming into the Weald are trying to access ‘tight oil’. This will need unconventional methods to access it. It requires (in the words of the industry) ‘Back to back’ drilling, multiple horizontal spurs travelling for kilometres under ground. Acids and other chemicals to access it (likely to be a more toxic flare) and great amounts of toxic flow-back fluid. The chemicals underground can leak between rock strata for long distances (thence the contamination risk). In the US they can’t think how to safely dispose of the radioactive flow-back, so they re-inject it into the ground. This is destabilizing once stable rock-strata. This is why the states are experiencing so many more earthquakes than before, particularly in high oil/gas producing regions. The Weald is a much faulted area, re-injecting flow-back will also increase seismic risk for us. The industry would like us to see it from one angle ‘just a flow-test’ but you have to see the bigger picture and where this is all leading too. An absolute industrialization of the Weald, and an assault on it’s roads, air and geology. It cannot be compared to off-shore oil fields.

  3. Kathryn. Thanks. My reply was more around whether Cuadriller, by not using green completion during the well test was being naughty. My thought was, not so, as green completions are for frack flowback.
    I will leave others to discuss acid stimulation vs fracking and so forth as I only have experience in scale squeeze, and various acids.

    • Hewes62, green completions are currently required only at production stage. No doubt regulation/law will be changed to remove that requirement when we get that far! And yes, all the law and regulation and planning advice is about fracking, so we are not protected by being in an AONB, or by the fact that our top micrite layer is only 600m deep when you are not allowed to frack at that depth. None of the (feeble anyway) fracking regs apply to acidisation. Ultimately they will want to acid frack (as it has always been called in the industry when the rock is actually fractured, but under the government’s new definition of fracking (taken from some random report done for the EU but not consistent with industry understanding of the term) this will not count as fracking because it will not use the statutory amount of fluid – especially with the use of modern gels, squeezes, fishbones, whatever. Almost funny how they call their flowback/produced water ‘salty water’! Let’s have a gargle. And let’s hope the EA will refuse their request to remove the mining waste status of the flowback/produced water. Because mining waste it is. Anyway, what is far worse that ‘naughty’ is the game of words – incorrect definitions of conventional and fracking, cooked up to circumvent the legal and regulatory obstacles and speed the early bits into the ground.

  4. The photograph of the Balcombe site in 2013 MAY be genuine but in the tradition of “fake news” you fail to mention that it could not have been taken from anywhere in the village or from the public road passing the site, from which it is almost totally hidden.

    Turning to various comments, please note that drilling in 2013 caused NO environmental damage, there were NO earthquakes, NO one’s tap water caught fire, NO one was kept awake at night, property prices went up, not down & indeed but for the protesters very few villagers would have noticed anything at all.

    Based on past experience a week’s test drilling will be less disturbing than one bonfire night provided only that protest mobs are firmly controlled.

    Instead of pointless protest and negative fear spreading, why not be positive & attempt to secure some benefit for the village?

    We are all aware of the financial constraints faced by Balcombe School. For the immediate future perhaps we should ask the landowners to give a proportion of their rent to the school? (My apologies if they already do so).

    Longer term, if we do have a nodding donkey down the road , let us campaign for a “royalty “ payment to the school or other village institutions.

    There is a choice: self-indulgent protest achieving nothing but disruption & a huge drain on public funds OR accept just a little possible inconvenience as a small contribution to our national economy ,our energy security, the environment (yes indeed), & ,with some effort, a worthwhile contribution to our school & amenities.

    Protesting may be fun but it butters no parsnips nor pays for more school teachers!

  5. It identified measures to reduce risks. These included:

    Comment: A digital and paper record should be kept, where appropriate, of the following ‘reduce risk’ factors (mentioned above), and available for public inspection:

    1. “Use of Environment Agency authorised haulage/delivery companies”.
    Comment:Names of the approved E.A. authorised haulage/delivery companies.

    2. “Visual inspection of tanks during site daily H.S.E. tours”.
    Comment: Photographs of these tanks, in order to show their adequacy for storing the hazardous liquids. Inspections should be logged.

    3. “Wellhead, pipes and flare stack designed to prevent fugitive-gas-emissions”.
    Comment: Close-up photographs of the wellhead, pipes and flare stack.

    4. “24-hour supervision of pipes and flare during flow testing”.
    Comment: Staff logs and duty rosters with appropriate entries where visual inspections have taken place.

    5. “Flare designed for complete combustion at temperature in line with BAT [Best Available Techniques] requirements”.
    Comment: Temperature monitoring of flare stack to show complete combustion.

    6. “Ability to shut in the well in the unlikely event of an inefficient burn”.
    Comment: Safety procedures in place to prevent blow-back.

    7. “Temperature monitoring and recording of flare at base and tip. Continuous monitoring”.
    Comment: Digital and analogue monitoring, including using paper read-out where appropriate.

    8. “Testing of pipework and joints before flow testing”.
    Comment: Pressure-testing before gas release, above ambient, with a suitable Factor of Safety.

  6. Sorry Rod, I’m afraid I have to disagree with you. I was kept awake at night by the drilling, I phoned the EA at 3am out of sheer frustration. I know people on Oldlands whose porches vibrated with the sound. I know people who lived well into the village and could work out, using their instruments in the house, which note the drill was on and when it changed to a sharp or a flat. Large numbers of the village went down to the site at various events, we know because on the petition that was collected mainly down there or at meetings there are well over 300 signatures that can be easily identified as residents of Balcombe. What about all the parents at the school who complained that they were having to wait for huge articulated lorries to pass, (when they weren’t supposed to cross at pick up and drop off times)? I can remember walking down Deanland road and trying to work out at what point the drill sound became inaudible, it varied on different nights depending on the weather conditions. Sometimes you could hear it the length of the road. I also remember hearing the loud shocking screaming drill the day they put the water bore in. After all that though, we know they are not proposing nodding donkeys. No, I along with the majority in the village (as born out by 3 separate surveys) do not want to see work continuing down there.

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