Oil firm reveals production plans for 500+ tonnes/day at Horse Hill


Initial flow testing on the first well at Horse Hill, Surrey, 3 February 2016. Photo: Eddie Mitchell

The company behind the Horse Hill exploration site near Gatwick Airport has released details of plans to drill four more wells to produce oil for 20 years.

Horse Hill Developments Ltd said the scheme could take production to more than 500 tonnes of oil a day. If achieved, this would make Horse Hill the UK’s second largest onshore producing site on current figures.

The proposal would increase the size of the Horse Hill site by a quarter and increase to six the number of oil wells.

According to the details, available online, the site near Horley would also accommodate a well to re-inject produced water. Horse Hill production scoping request (pdf)

Added to this there would be: six surface mounted pumps, seven oil storage tanks, two fire water tanks, two produced water tanks, an enclosed ground flare, an oil heater with an exhaust stack, four gas-to-power electricity generators with acoustic enclosures, oil separators and above ground pipe and cable tracks.

The details are in a scoping request – the first stage of a planning application that would require an environmental impact assessment.

The document said the production proposals would increase the site from 2.08ha to 2.6ha by adding land immediately to the east of the existing well pad.

1809 Horse Hill production plans

Plan submitted with scoping request for Horse Hill Developments Ltd

This is the third major application sought for the Horse Hill site. The original exploration well (HH-1) was approved in 2012 and drilled in 2014. It is currently undergoing long-term flow testing. A second application, granted in 2017, allowed Horse Hill Developments Ltd (HHDL) to drill another appraisal well (HH-2) and a sidetrack (HH-1z).

The new proposal is to produce oil from the site, drill the extra oil wells (HH-3 to HH-6) and water re-injection borehole and to develop hydrocarbon processing, storage and transport facilities.

The scoping request acknowledged that wells could be drilled at the site for more than a year. It also accepted that the impacts of construction on the existing well site could coincide with construction of the new area. The transport effects of drilling the wells could also be experienced at the same time as the transport effects of production.

The document variously estimated that the nearest homes were about 225m or 321m from the site. It accepted that the proposals would “significantly change the landscape” and give rise to “an adverse effect upon valued landscapes and the visual amenity of the area”. It also said that significant noise effects were expected from several phases of the work.


(information from HHDL’s scoping request)


HHDL said in the document:

“The duration of drilling activity followed by the placement of production facilities for 20 years has the potential to significantly change the landscape and visual baseline giving rise to an adverse effect upon valued landscapes and the visual amenity of the area.”


Potential effects predicted from the development included light spill, glare and sky glow.


The document said:

“Each phase of development has the potential to generate noise effects upon nearby sensitive receptors”

Significant noise effects could be expected from well site modification and construction works and the drilling and well management phases, the document said.

Ground and groundwater protection

The proposed development included the use of drilling muds, cement and well development fluids, the document said. The wells would produce oil, gas and water, which may contain naturally occurring radioactive materials.

Air quality and climate change

The development would produce pollutants from electricity production from gas, flaring of gas and the use of diesel engines, the document said. HHDL said it would assess nitrogen oxides, carbon monoxide, sulphur dioxide, volatile organic compounds, particulate matter and dust.


HHDL predicted that the impact of the scheme on the nearest sensitive wildlife was not likely to be significant because the site was already well-established. But it said it would assess the impacts on ecology, nature conservation, biodiversity and arboriculture.


HHDL said the traffic impacts from the different phases of the work were considered “not significant”.

Socio-economic impacts

HHDL said the benefit from indigenous hydrocarbon development was considerable at “a national level”. Locally, it said the development would generate employment. The adverse effects on local tourism and other sectors would be low, it predicted.

Other impacts

The scoping report said the effects were not likely to be significant on vibration, listed buildings, loss of agricultural land, waste generation, human health, residential and recreational amenity, risk of accident or airport safeguarding.

Proposed work phases

(information from the scoping request document)

Phase 1: Well site modification and new construction work

Existing site: construction work
Duration: six weeks
Average daily HGV movements: five

Existing site: Installation of four surface conductor casings and site preparation for water re-injection well
Duration: six weeks
Average daily HGV movements: five

New site: construction of oil processing and storage area, tanker loading facilities, placement of generator sets for generating electricity from gas
Duration: 14 weeks
Average daily HGV movements: 17

Phase 2: Well drilling

Workover rig mobilisation
Duration: two days
Average daily HGV movements: 28

Initial workover operation of HH-1z and HH-2 wells
Duration: four weeks
Average daily HGV movements: seven

Workover rig demobilisation
Duration: two days
Average daily HGV movements: seven

Drilling rig mobilisation
Duration: nine days
Average daily HGV movements: 14

Drilling four new hydrocarbon production wells HH-3 to HH-6 and drilling one new produced water re-injection well
Duration: 60 weeks
Average daily HGV movements: nine

Drilling rig demobilisation
Duration: Three days
Average daily HGV movements: 29

Phase 3: Production and export of oil and electricity for 20 years

Installation of production equipment

  • Surface mounted pumps (one for each well)
  • Seven oil storage tanks (1,300 barrel capacity/tank)
  • Two fire water tanks
  • Two produced water tanks
  • Enclosed ground flare
  • Oil heater with exhaust stack
  • Four gas-to-power electricity generators and acoustic enclosures
  • Oil separators
  • Ancillary pumps
  • Above ground pipe
  • Cable tracks

Duration: 12 weeks
Average daily HGV movements: nine


Oil will be pumped to the surface along with formation water and gas. The oil will be separated to storage tanks where it will be exported by tanker to a refinery. Formation water is re-injected. Gas is used to generate electricity for the site or for export. Flaring of gas will happen in an emergency or for maintenance purposes. Production could exceed 500 tonnes of oil per day, which would require up to 16 two-way oil tanker movements per day.
Duration: 20 years
Average daily HGV movements: 32

Well management

This could include: cleaning the pump and well; hot oil treatments to unblock restrictions; changing pumps or producing tubing; drilling a sidetrack to access a new part of the reservoir.
Work over mobilisation
Duration: two days
Average daily HGV movements: 28
Duration: two weeks
Average daily HGV movements: 14
Workover demobilisation
Duration: two days
Average daily HGV movements: seven
Sidetrack mobilisation
Duration: Nine days
Average daily HGV movements: 14
Sidetrack drilling
Duration: 15 weeks
Average daily HGV movements: seven
Sidetrack drilling demobilisation
Duration: three days
Average daily HGV movements: 29

Phase 4: Plugging, abandonment and decommissioning

Workover rig mobilisation
Duration: nine days
Average daily HGV movements: 14

Plugging and abandonment
Duration: 18 weeks
Average daily HGV movements: 10

Workover rig demobilisation and removal of surface equipment
Duration: two weeks
Average daily HGV movements: eight

Phase 5: Site restoration

Duration: five weeks
Average daily HGV movements: 17


45 replies »

  1. Signifies commerciality at Horse Hill and specifically from the Kimmeridge. This supports the hypothesis that the Weald is nationally significant.

    • No, my friend, specifically NOT from the Kimmeridge. HH is a nice little conventional oilfield reservoired in the Portland Sandstone. The last RNS update from UKOGL on 10 September discussed good results from flow testing the Portland; testing of the Kimmeridgian micrites had not even begun. The new scoping document makes no mention of which formations will be producing the anticipated oil.

      • “The prospective applicant has indicated their intention to provide an Environmental Statement alongside the application for planning permission that is to be made in respect of the proposed drilling of an additional four wells at the established Horse Hill Well Site (Planning Permission RE10/2089 and Planning Permission RE16/02556/CON), the installation of equipment and infrastructure necessary to the production of hydrocarbon, and the extraction of hydrocarbon from the Portland Sandstone and Kimmeridge Limestone members. The anticipated operational life of the well site would be 20 years, subsequent to which it would be decommissioned and the site restored. The prospective applicant anticipates that, at peak, production could achieve rates in excess of 500 tonnes of oil per day.”

        You were saying?

        • Furthermore, per RNS of 10th Sept….364 bopd from the Portland. 6 wells at HH, if they were to be Portland only would mean 6 * 364 = 2,184 bopd…nowhere near 500tonnes+ which equates to 3500+ bopd. Where do you think the rest is coming from?

          Sorry to say it old-timer, but you’re wrong, and not for the first time.

          • Oh, and….”In anticipation of declaring the HH-1z oil discovery commercial, HHDL intends to submit a planning application for the production of hydrocarbons from the Site.”

            HH-1z is a sidetrack into the Kimmeridge, as we all know.

          • As usual with UKOG, this is all speculation at present; there is no proven long-term flow from the Kimmeridgian. Your figures actually prove my point. The Portland is expected to produce 300 t per day, and “the Site could briefly produce in excess of 500 tonnes of petroleum per day”, so that’s why the figure of 500 is mentioned. A long way short of David Lenigas’s ‘Gatwick Gusher’.

            • If memory serves, you said the Kimmeridge wouldn’t flow yet it flowed naturally at record breaking rates for UK onshore. We’ve learnt to take what you say with more than just a pinch of salt.

            • Your second comment above again proves my point – “in anticipation of …” – i.e. optimistic speculation, not fact.
              As an ‘old-timer’ (your phrase) I have noticed that UKOG’s recent mapping of the Portland puts the Collendean Farm-1 well, situated NW of HH, some 140 m NW of its correct position, and apparently drilled in 1964 in a stream! Just another little error on UKOG’s part. Incidentally the 2009 Magellan (UKOG’s partner) prognosis had the well in the correct location. You see, as an ‘old-timer’, I took the trouble to visit the site last week and speak to locals about where CF-1 actually was drilled.

            • “In anticipation of…” isn’t just fanciful optimism, no matter how much you’d like it to be.

              Something that is expected i.e. with a degree of certainty e.g. based on data and knowledge gleaned, can also be “anticipated”.

  2. I’m sure anyone who lives near there will be very concerned about this major industrial development on their doorstep. Is that the sound of house prices falling I can hear?

    • Or maybe said locals will look at Wytch Farm and base their response on facts and the real experiences of those living in the vicinity of such a significant yet low impact operation, rather than scaremongering bluster from antis who cause more disruption than the oil company themselves?

    • Sorry but to fuel our modern life styles we need to take resources from where we can find them. This is not 25th century when hopefully energy problems will be sorted. Here and now we need to take what we can get. You, me and everyone reading this, commenting is using those resource. It is better to take them locally, rather than from other poorer countries where people and environment (due to lower standards) suffer.

    • Not sure it’s “major industrial development” – I love the attemp at spin you guys put out there. Yes it will mean more lorries but isn’t that what roads are for? 1 extra lorry per hour average – if it didn’t have the hazard plates on it you probably wouldn’t notice it and assume they are tankers filling up your local petrol station (where you fill your petroleum car up)

    • We all want more affordable housing. This therefore has to be an upside for anyone with a sense of social responsibility. We can not let selfishness deprive the poorer in society of the chance of mounting the property ladder at a more affordable price.

    • Ellie

      Good to hear house prices are falling. But I guess they have a long way to go before they are considered affordable. Perhaps rents will drop as well. Allied to some real jobs in the area it sounds like win win.

    • Great perhaps our kids will now be able to afford to buy somewhere to live? Major industrial development? You have no idea what a “major industrial development” is…

  3. Superb news for Ukog and the Weald basin and quite clear now this oil is of national significance and will substantionally assist every single one of us via tax receipts to the Chancellor

  4. National, international and local need is for no new fossil fuel wells, conventional or unconventional, to avoid the tipping point for catastrophic human induced and rapid climate change. We ALL need to work to ensure the survival and thriving of our species. The planet will continue, but perhaps without humans. Extreme weather events will affect the US and many developing countries the worst, and first, but will increasingly impact on all of us. This well would not replace other supplies, just add to the total. The good news is more and more people are waking up and renewables are competitive, so this will shortly be a stranded asset, if it gets going at all.

  5. Which will have more impact upon house prices? HH or Gatwick Airport expansion?

    So, we have Gatwick ( and Heathrow expansion) and HH to provide the oil to produce the aviation fuel that the MAJORITY of the public want to utilise. Seems a decent sort of balance there. Perhaps Fawley Refinery, where there is a plan to spend £500m to expand production of diesel, will have a drop of oil for that too, replacing some of that shipped in from the Middle East.

    More indications this weekend that oil is heading to $100/barrel.

    Traffic? Compared to the traffic flow to and from the airport absolute minimal. Oh, good job the airport is there, the road network is already in place because of that. Motorway nearly all the way to Fawley.

    Technical “experts” on the anti side “might” just have managed their premature speculation incorrectly.

    “Stranded asset”…..what, a Tesla?

    Starting to look a bit like a perfect storm developing.

  6. Beat you to it Ruth Hayhurst on reporting this great news for Ukog Angus energy and uk economy and jobs for Sussex Great news win win for all Companies will also be giving % to local coffers too

    • Shouldn’t give it to local councils unless it goes towards renewable schemes,so it funds green energy,call it money laundering with a difference,after watching the idiots at some of the planning meetings they will waste every penny of it

    • Keith – no doubt this is correct. But the antis (with one or two exceptions only) on here are more worried about their house prices so as long as the meat industry is somewhere else – and the oil / gas / shale industry is somewhere else it is okay…..

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