Horse Hill new oil drilling and testing plans published


Well testing at Horse Hill in 2016. Photo: HHDL 

Plans for more drilling and testing at the exploratory oil site at Horse Hill, near Gatwick Airport, were published this morning.

DrillOrDrop has picked out key facts from the 62 documents that make up the planning application to Surrey County Council. The full documents can be read here. In future posts, we’ll report on reaction to the application and its progress through the planning system.

Application details


Site operator: Horse Hill Developments Ltd, a special purpose company formed of six shareholder companies, of which the largest is UK Oil & Gas Investments PLC with a 48% stake.

Agent: Barton Willmore LLP, Cambridge

Application reference: Surrey County Council 2016/0189 and link

Application description: Three-year application to retain wellsite and access; appraisal and flow testing of the existing Horse Hill-1 well (HH-1); drilling of a sidetrack to HH-1 and a second, deviated borehole followed by flow testing; installation of security fencing to a larger area plus acoustic and light barriers, plant, cabins and equipment; restoration to agriculture and woodland.


Image: HHDL


Address: Horse Hill 1 well site, Horse Hill, Hookwood, Horley, Surrey RH6 0RB

Size: 2.08ha – extended by 0.78ha to include additional security fencing and realigned access road

Location: 3.1km from Horley town centre, 2.3km from the village of Charlwood and 1.6km from the village of Hookwood, 2.2km from Gatwick Airport

Nearest homes: Wrays Farm House (370m), Fiveacres (410m), High Trees Court (350m)

Nearest business: Lomond Equestrian Centre (0.16km)

Access: 250m access track to meet Horse Hill road

Protected landscapes: The site is in the Metropolitan Green Belt. The Surrey Hills Area of Outstanding Natural Beauty is 6.99km away and 4.76km from the Surrey Area of Great Landscape Value

Rights of way: A public right of way runs along the southern boundary of the site and another is 400m to the north

Landscape Character Area: Dorking to Hookwood Low Weald Farmland Landscape Character Area

Nearest designated wildlife site: Edolph’s Copse Local Nature Reserve (1.8km), Mole Gap to Reigate Escarpment Special Area of Conservation (9.04km), Glovers Wood Site of Special Scientific Interest (2.81km), plus six Sites of Nature Conservation Importance within 2.5km.

Nearest heritage: Horse Hills and Woodlands Farm Houses (560m), Scotchman’s Copse – medieval tannery (4.17km), Reigate Priory historic garden (3.6km), plus 13 listed buildings within 1km.

The application mistakenly says Stansted Park Grade II registered park and garden is 900m away – this information is from the UK Oil & Gas application for Markwells Wood, also prepared by Barton Wilmore

Flooding: Flood zone 1 (low risk of flooding). At the EA’s request, a drainage pipe is to be installed in the gravel swale in the site on the west edge

Groundwater: The site is not in a groundwater source protection or vulnerability zone but it is in the Lower Thames Drinking Water Safeguard Zones established to protect drinking water from pesticides

Site description: Hard standing of existing HH-1 wellpad, with soil bunds, security fencing and access road

Surroundings: Farmland, hedgerows and woodland, with two small ponds in surrounding woods and Spencer’s Gill, a tributary of the River Mole, 590m to the south

Petroleum Exploration and Development Licence area: PEDL137

Horse Hill Protests

Protests during flow testing in spring 2016. Photo: David Burr

Planning history

16 January 2012: Surrey County Council granted planning permission for exploratory wellsite with one borehole and short-term testing (reference RE10/02089)

Autumn 2014: Horse Hill-1 well drilled and oil discovered in Portland Sandstone and deeper Jurassic formations including Kimmeridge limestones

February/March 2016: Flow testing resulted in nearly 1,700 barrels of oil equivalent per day – the highest of any UK onshore exploration discovery well

16 May 2016: Pre-application meeting with Surrey County Council planning officers about further proposals for the site, including extended well tests and new wells

28 June 2016: Surrey County Council confirmed an Environmental Impact Assessment was not required

21 July 2016: Public exhibition about the plans at Charlwood Parish Hall, 2pm-7pm

14 October 2016: Latest planning application submitted

27 October 2016: Latest planning application validated


Rig section. Image: HHDL

Development proposals

Phase-1: 210 days in total

  • Site enabling works
    • Erection of security fencing to a larger site area
    • Installation of 81m long, 6m tall, 1.5m wide acoustic and light barrier along southern boundary of the well pad
    • Removal of 2 trees to south of well pad for security reasons and a group of other trees to straighten the access track
    • Installation of security cabins and welfare facilities, including diesel generator and toilets
    • Installation of temporary offices, living accommodation, canteen, toilets, shower, laundry and waste tanks
  • Workover
    • Workover rig to make new perforations in HH-1 well
    • Installation of  flow test and rod pumping equipment
    • Rig expected to be about 32m
  • Acidisation
    • Use of coiled tubing unit to acidise the HH-1 borehole.
    • The application says this is to clean out cement debris from perforations and enabling oil to flow more freely into the wellbore
    • Pumping of 15% hydrochloric acid solution into the well
    • Spent acid returned
    • Waste sent to licensed site
  • Extended well test
    • Equipment installed, including flare stack, pumps, degasser, settling tanks, separators
    • Extended well test of HH-1 to confirm whether volume and flow of oil is economically viable
    • Pumping may be required
    • Oil and produced water removed by road tanker

Phase 2 (dependent on outcome of phase 1): about 100 days in total

  • Mobilisation of rig (BDF51 or similar), 37m high
  • Drilling deviated sidetrack from existing HH-1 borehole
  • Workover of HH-1 sidetrack well
  • Acidisation using coiled tubing unit to HH-1 sidetrack
  • Extended well test of up to 75 days to HH-1 sidetrack

Phase 3 (dependent on outcome of phase 1): about 110 days

  • Construction of new well cellar next existing HH-1 cellar
  • Mobilisation of rig
  • Drilling new appraisal well, Horse Hill-2 (HH-2) from existing well pad
  • Workover of HH-2
  • Acidisation using coiled tubing unit to HH-2
  • Extended well test of HH-2 for up to 75 days

Phase 4 (if the oil is not commercially viable): Up to 22 months

  • Decommissioning of site
  • Wells plugged and abandoned
  • Removal of equipment, structures, access roads and impermeable membrane
  • Replanting of trees
  • Restoration to agriculture and woodland

The application said the phases may not be carried out consecutively and phases 2-4 may not follow immediately after the preceding phases.

Future production

The application stated:

“In the event that the appraisal programme demonstrates commercial viability HHDL intends to submit a further planning application for a production phase in due course.”


The transport statement says there will be 10 heavy goods vehicles (HGV) going to the site and 10 leaving every day for the 14 month operational phases of the development.

The application acknowledges:

“There will be an increase in traffic movements mostly during rig mobilisation and demobilisation, resulting in minor effects from disturbance and delivery of unconventional loads although this will be managed through a Transport Management Plan”.

It added:

“The temporary increase in traffic volumes and especially the HGV component of the traffic volume could lead to adverse highway safety impacts”

But it concluded that the development would generate a 0.11% increase in traffic on the A217 north of the junction with Horse Hill and a 0.59% increase in HGV traffic.

The application said HGV movements would be 7am-7pm Monday-Friday and 7am-1pm on Saturday.

The application gives the following maximum traffic movements, where one movement counts as two journeys, one in and one out

Phase 1

  • Site preparation: 20 in total over 30 days
  • Workover and extended well test for Portland formation: 10 per day for 68 days
  • Demobilisation for Portland formation extended well test: 20 over 2 days
  • Mobilisation for Kimmeridge formation extended well test: 20 over 2 days
  • Workover, acidisation and Lower Kimmeridge extended well test: 10 per day for 76 days
  • Demobilisation for Kimmeridge formation extended well test: 20 over 2 days

Phase 2

  • Mobilisation for HH-1 sidetrack: 50 over four days
  • Drilling sidetrack: 10 per day for 25-35 days
  • Demoblisation for drilling HH-1 sidetrack: 50 over four days
  • Mobilisation for HH-1 sidetrack extended well test: 20 over 2 days
  • Workover, acidisation and extended well test: 10 per day for 75 days
  • Demobilisation for HH-1 sidetrack extended well test: 20 over 2 days

Phase 3

  • Mobilisation for HH-2 drilling: 50 over four days
  • Drilling HH-2 well: 10 per day for 35-45 days
  • Demobilisation for drilling HH-2: 50 over four days
  • Mobilisation for workover, acidisation and extended well test for HH-2: 20 over 2 days
  • Workover, acidisation and extended well test for HH-2: 10 per day for 76 days
  • Demobilisation for workover, acidisation and extended well test for HH-2: 20 over 2 days

The proposed transport management plan would set out an agreed access route, scheduling of HGV movements to avoid peak traffic, signage to identify access routes and a code of conduct for drivers.


Estimated lorry movements. Source: HHDL

Proposed working hours

Phase 1

Site preparation: 7am-7pm Monday-Friday, 7am-1pm Saturday

Extended well test: 24-hours a day, 7 days a week

Phase 2

Drilling and extended well tests: 24-hours a day, 7 days a week

Phase 3

Drilling and extended well tests: : 24-hours a day, 7 days a week

Phase 4

Site clearance and enclosure of wells: 7am-7pm Monday-Friday, 7am-1pm Saturday


The application said solid and liquid waste would be stored on site in sips or tanks before being taken off-site for disposal.

Gas produced by the extended well tests would be flared in a 10m high flare stack.


The application said noise during site preparation could be classed as “minor adverse significance” because operations may be audible at nearby homes.

During drilling, the sound of the rig may be greater than background levels at night, the application said. Without acoustic screening, noise would exceed nighttime noise limit of 42 decibels at the nearest homes and would count as moderate adverse significance.

During the extended well test, the application predicted noise would be similar but not exceed, that in the drilling phase and was “unlikely to be audible beyond the site boundary at any time”.

It forecast that the following noise levels would be met with the acoustic screen in place on the southern boundary:

  • Site preparation and retention: day 65db; no work scheduled in the evening or weekends
  • Mobilisation, workover, and drilling: day 48db, evening and night 42db
  • Extended well tests: day 48db, evening and night 42db


The application added:

“Further measures to mitigate noise will be applied at source where possible including turning off engines when vehicles or equipment are not in use and reducing the drop height of materials.”

The application said vibrations from the site would “not be perceptible” at the nearest homes.


The planning statement did not specifically say that the site will be lit at night. It did, however, say the rig would be lit and lighting would be positioned inwards and downwards using the lowest level required. A 6m lighting barrier would be installed along the southern boundary.

It said lighting would be switched off at night where possible. Lights would be selected that had “minimal disturbance” to bats, the application said.

It concluded:

“the overall effects of the development’s lighting would be minimal as the site is located within a woodland area. The significance of impact in terms of sky glow would be minor to moderate adverse and the impacts in terms of light intrusion and luminaire intensity would be negligible”.

Air quality

The application concluded that emissions from flaring during extended well tests would lead to increases in pollutants, particularly nitrogen dioxide and PM10 and PM2.5 particulates.

But it said with mitigation the “effect of these increases in concentrations on existing sensitive human health and ecological receptors has been shown to be insignificant.”

The application added that there would be no significant impact of dust from site construction with suitable measures in place. Road traffic emissions were considered “insignificant”.

The site is 2.26km from the South West Horley Air Quality Management Area, designated in 2003 because of nitrogen dioxide concentrations.


The application said:

“The development of the Site as an onshore oil exploration well site in 2014 has already altered the character of the Site itself without significantly changing the character of the surrounding landscape, and it is not considered that further works will impact upon the historic landscape character type as a whole.”

Ecology and nature conservation

According to the application, six species of bats were recorded within 4km of the site. There were also records within the area of dormice, hedgehogs, protected bird species, smooth newt, common frog, grass snake and great crested newt. It acknowledged evidence of badgers in neighbouring fields and woodland but said no active sets were found within 100m of the site.

The application recommended moving a population of great crested newts which used the attenuation ditch on the site.

The application concluded that with mitigation the development would “meet all current legislation and planning policies relating to ecology.”


Impact on views and landscape

The application said:

“There will be some views of the drilling rig during operations, although lower and middle parts of the rig and site will be mostly screened from view by woodland and topography. The greatest potential for adverse effects is likely to be upon users of the local PROW to the west of the Site, extending to the route that follows parallel with the southern boundary. The proposed acoustic/light barrier will provide mitigation that will reduce the impact of the visual effects of the Development.”

Water and flooding

The application said there were no licensed water abstraction points within 1km of the site. It added that the area was “not characterised by a significant use of groundwater for water supply purposes”.

A risk assessment by the applicant of water contamination concluded that with mitigation there was a negligible risk from all activities on the site.

It also concluded that the development would not increase run-off rates or volumes of surface water from it.

Public consultation and decision

Surrey County Council confirmed that the public consultation on the application opens next week. The usual duration is 21 days. The council said the deadline for comments had not yet been fixed but would be given in notices in local papers and at the site.

The council said the earliest date for a decision by the planning committee was 22 February 2017. But the decision date could be delayed if further information were needed for the application.

Link to application and consultation information 


25 replies »

  1. This is preposterous. Horse Hill is on a fault line approx one mile from the world’s busiest single runway airport. If there are earthquakes resulting from the fracking can UKOG and HHDL afford the consequences? The water table is very close to the surface her and this area is in the lower Thames drinking water safeguard zone established to protect drinking water. We know that all the fracking waste water and flowback cannot be totally recovered and some will find its way into the water table and aquifers. I on,t think the local population are aware of the seriousness of this project including future residents of a 1500 dwelling development less than a mile to the east of the drill site.

    • Mrs Shepphard,

      Making false claims that HorseHill will be fracked is just pure scare mongering by anti fossil fuel activist.

      Horsehill was inundated by so called anti fracking activist in February and March this year when clearly UK oil & Gas had no intention or permission to frack at Horsehill.

      The well was above the minimum fracking depth at the time to.
      The main noise and nuisance to local residents was from the activists slow walking in front of tankers and delivery lorries screaming and shouting and singing songs half the night from their camp at Horsehill and jumping on top of tankers and even one of the so called anti fracking protesters uncoupling brake lines on a fuel tanker lorry.

      These are the actions that put peoples lives at risk not producing onshore UK oil for the good of the UK economy.

      • Unfortunately Mr Watkins
        What puts people’s lives at risk is toxic gases being flared, water contamination from the acidised water being used and radioactive substances released in the process contributing to climate change.
        Where do you stand on the Paris climate change agreement?

  2. To Mrs Jane Sheppard

    It is always better to know what you’re talking about before posting. UKOG have made it very clear that they will not be fracking.

    Your response highlights the scaremongering of the media and it’s followers and it’s not helpful for those that wish to make UK a place where we are self reliant and not a major importer.of it’s energy.This is a potential game changer for the UK and should be embraced.

    At this point in time oil is still used at a high level and whilst it will reduce over time it will be here for many decades to come, so we should all learn to live with it rather than listen to the negative people who don’t have a clue. I would suggest you read all the documents that have been submitted before posting…….

    • I lived with the first round of flow testing and experienced hgv movements, the police, light pollution from the rig, and headaches from the gases being flared. I don’t need to read all the 62 documents.
      The figures produced from that flow test were massaged – for production to be commercially viable Mr Sanderson himself said there would have to be back to back wells right across the Weald basin. I suggest you need to do a bit more homework, RTFM

      • They didn’t flare any gases during the test.
        There are far more movements of heavy traffic by the farmers.
        Back to back wells all over Weald – rubbish. Clusters of wells in small areas with all pipework and pumps concealed
        Drama queen

    • ‘and whilst it will reduce over time’

      What is your time scale for this ‘reduction’ and reasons why?

      Renewable technology is here now and works fine. There is no practical reason why the UK could not ramp up proven renewable sources today instantly reducing our imports.

      The grid can take 50% renewable s without major upgrades. We currently have nowhere near that amount.

      ‘It is always better to know what you’re talking about before posting’

      I suggest it is you who does not have any idea of the reality of climate change, global economics, energy security, and that your suggestion that ‘it will be here for many decades to come’ is based solely on the basis that as we have been using it then we will continue to do so ( but only for an undisclosed time)

      No science, no evidence, no consideration of legally binding targets, just a hunch.

      You are however not alone. Most pro frackers say renewable s are the future but when asked cannot explain why not today.

      • Hi John,

        You need to have a close look at what you are saying. Renewables installed capacity end Q2 2016 was 32.5GW. This coming winter total installed generating capacity quote National Grid 2016 -17 Winter Outlook is just under 74GW so renewables are not quite 50% yet. However when the low load factor of wind is incorporated (and other renewables plus any maintenance etc.) the 74Gw is derated to 55GW:

        “Our analysis is based on a de-rated generation capacity of 55 GW. The capacity margin assumes an average cold spell (ACS) peak demand of 52.7 GW and net interconnector imports of 2.0 GW.”

        You can download the report here:

        Table 2 on Page 17 shows the assumed availability of each type of power station type:

        Table 2

        Power station type Assumed availability
        CCGT 88%
        Coal and biomass 87%
        Hydro 86%
        Nuclear 84%
        OCGT 94%
        Pumped storage 96%
        Wind EFC 21%

        Look at wind – winter, highest demand period, load factor of 21%, due to high pressure, cold weather = no wind for long periods of time. Why would anyone want more wind turbines???? Look at CCGT (gas for those that don’t know) – 94%

        Renewables contributed less than 25% of our electricity in Q2 2016 despite being nearly 50% of our generating capacity. Perhaps this is why more coal has been used recently as gas appears to be flat out?

        • And John, from the same report:

          Equivalent firm capacity
          In order to estimate the amount of available wind generation that we may
          expect at peak, we use the EFC. This measures the entire wind fleet’s
          contribution to security of supply. It represents how much conventional
          generation plant with an availability of 100 per cent would be needed to replace
          the entire wind fleet and leave security of supply unchanged. This approach
          to wind modelling combines the risks from wind variability with conventional
          system risks, such as high demand or low availability of conventional
          The wind EFC depends on several factors, including how much wind capacity
          is installed on the system. As installed wind currently makes up a small
          proportion of total generation, conventional risks remain the biggest threat
          to system security. As a result, the EFC is very close to the mean load factor
          for wind generation. In the future, as the proportion of installed wind capacity
          continues to increase, the risk that the variability of wind will have an impact of
          system security also increases. This will result in a decrease to the EFC.

          In a nutshell, more wind is bad and expensive…..

  3. HORSE HILL IS NOT GOING TO BE FRACKED. It is illegal in this country to frack at a depth above 1000m. Horse Hill is a conventional discovery, and will be developed as such. I understand the concerns of the renewables/green lobby, but I cannot accept the ignorance of those who cannot accept oil consumption is needed for the next decades until an alternative for oil bi-products is either discovered or invented! The renewables revolution is coming, Elon Musk is leading the way, but plastics, lubricants, detergents and hundreds of other oil-bi-products will be needed to ensure the revolution is possible!

    Mrs Sheppard and Mr Powney might I suggest you take some time to engage with UKOG who are leading in communications with the local community and other stakeholders. Information is easily accessible and I wonder if you participated in any of the locally organised meetings to date? Try here:

    [edited by moderator].

  4. Better worded than my effort Gordon Big but says the same and a bit more:)

    Not fracking, need to use the UK’s resources and not other countries etc etc


  5. What a great opportunity for the UK to be less reliant on imports. Plenty of countries have conventional oil drilled without this NIMBY attitude and the safety requirements there are a lot less than ours. Its not fracking.

  6. UKOG you’re ‘aving a laugh. Are you really not going to use unconventional extraction methods to get at all the oil and gas against your parent company’s previously publicised wishes ! As for the term Fracking, the gov has changed the meaning lol. Note we don’t have child poverty in the UK anymore because of this ruse ! Your company put out outrageous claims regarding the potential for this well – I think most people would be advised to run away from investing here as I don’t believe a word that has been written or said.

    • Here here ! The test figures they reported from earlier this year were fudged.
      Production from 3different levels were added together so the results looked impressive.
      However as far as I know you can’t extract from 3 different levels simultaneously!!

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