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. Speaking as a local resident, I am very sad to see this, in the green belt where you can’t even build a large shed, yet you can dig 2 km in the ground, under people’s home, pump in all kinds of chemicals and reinject produced water. We have had 12 earthquakes this year, pretty much unheard of in this area, and the link between earthquakes and reinjection of waste water is well established. Stephen Sandersen has already told locals he views this area as a sacrifice zone. Not nice to hear your home being spoken about like that, by a company who are boasting about wasting (flaring 15 000cu ft) the equivalent electrical output of 7300 solar panels, every day. Why do we spend thousand of £ of our own money for roof top solar just to have these people squander our air quality and climate? .

  2. Maybe it is fake news by ukog. They just put outa speculative good news to pump their share price.
    These plans may never happen nor their intentions to carry it through.

  3. Oh-unfortunately you are probably correct. But, that is the local democracy that many seem to want.

    I just hope, if the Weald is proven to be a significant oil producer then such funds could be pooled and professional management utilised to cut out that sort of waste. The Norwegians seem to manage it pretty well.

    The (earthquakes) tremors have disappeared since UKOG started to remove oil from HH, Lisa. Now, there’s potential for all sorts of speculation, and fabrication, around that! How about starting with the pressure cooker comparison?

    1st October-household energy bills up again today, for many. Air sourced heat pumps could be a good alternative around HH with all that flaring, and heat from all those aircraft.

  4. Thanks Paul, and you are right about local nimby’s, I think the point I was trying to make is that there are many many polluters out there and its always the motor car or the oil industries that take the flack. (ex diesel mechanic) so just having a rant!

  5. This is a good thing. More green to produce oil onshore than import from overseas. All those who voted Brexit on the back of this county being self sufficient should welcome onshore oil extraction. It has been proving that the earthquakes have nothing to do with the drilling by those so called professionals due to the direction of the fault lines . Now we just need those anti frackers making out that UKOG are fracking which they have repeatedly said that they aren’t. Yes I am invested. I’m in vested in a U.K. company extracting and producing oil for the benefit of this country . Whether you use oil/petrol or oil based products, you should support this imo.

  6. 22m tonnes of oil in and out of Fawley each year-most of it imported from the other side of the world. Fawley set to expand. Pipelines to the airports from Fawley being rebuilt. Large quantities of water taken out of the Solent for cooling purposes, returned cleaner than it was when extracted.

    On shore oil from places like Wytch Farm-the largest on shore site in Europe- been producing for decades. No issues. House prices astronomically high, nature reserves around the site. Smaller sites like Stockbridge. Anyone know Stockbridge? On the River Test, one of the prime trout fisheries in the world. Full of fish and crystal clear water.

    On shore oil extraction in UK hardly the environmental demon some would make out. Ahh, we don’t need it? Erm-22m tonnes?? At the moment, we do.

  7. Let get production oil gas electric asap .For the good of the uk /job / brexit and local Sussex economy.I just hope Angus energy Ukog come out with huge flow test in next few day Remember angus has production license in place ready to go into full production

  8. At the end of the day this country for now consumes something like a million barrels a day, half of which we import from the war zones of the middle east or from American fracking or even worse Canadian tar sands (If you want to see environment al catastrophe take a look at those operations). Transported in giant tankers half way round the world with all those inherent pollution risks,burning fuel the whole way.

    Although the great hope is in 20 years time to all be using electric cars etc, that is not the case now and frankly we won’t get even close for some considerable time. Also need to wean ourselves off plastic of course.

    That being the case then from a ‘green’ perspective getting oil cheaply from down the road using conventional, none fracking techniques is as good as it gets.

    Although I understand there maybe some short term visual impact during construction the site will can soon be hidden with tree’s, bankings etc. eventually it will be removed completely.

    I agree the 15000 cubic feet gas waste is a shame, but that will be corrected in these plans and used for electricity production. They couldn’t build electricity generators till they knew they had a viable gas source.

    Regarding the earth quakes this has already been ruled out as a the time the wells nearby were completely shutdown awaiting equipment and had been for several months.

    Just a reminder to the many out there who keep repeating this nonsense, this is not fracking. The oil companies would never frack here, as it would wreck the natural oil flow through the natural rock fractures.

    • The earthquakes (another one of which occurred on Friday last week) have not been ruled out, regardless of how many times you try to say they have. We will be in a far worse position post Brexit if we have to import our drinking water because our aquifers are contaminated, have you read the list of chemicals used in these techniques? Did you see the report of Balcombe about unexpected high pressure water produced? Oh, and have you noticed the significant increase in number of people cycling these days, and ditching their cars?…

      • Like all these protestors don,t drive car .Selfish nimbies .Not in my back yard selfish lot .We need Uk onshore oil and gas .Now with brexit and North Sea oil production in rapid decline. Water produced will be isolated it reduced to 6% second testing .Read the RNS and learn

        • As I said, a growing number of people are ditching cars and cycling / using public transport. Only 35% of 26 – 31 year olds now hold a driving license.
          There have been no earthquakes of not in this area for about 500 year, now there are about 13 just 2 years after the Horsehill well was flow tested and produced water from Lidsey was reinjected at Brockham. one of them was 4.1, what will the next one be?

          • Lisa – perhaps young people cannot afford a car due to high rents / house prices / no jobs? Great to use public transport when you have it available but most rural areas (in the NW at least) have very limited Public Transport – and buses that pass my house are nearly always empty / one or two passengers only / free buss pass over 60’s.

            And how many people drive their kids to school?


            “People in their 20s who want to rent a place for themselves face having to pay out an “unaffordable” amount in two-thirds of Britain, BBC research shows.

            They face financial strain as average rents for a one-bedroom home eat up more than 30% of their typical salary in 65% of British postcode areas.”

          • Lisa

            2016 statistics ( BBC or Statisca ) show an increase in car use in England year on year, with the largest increase in the SE of England ( which excludes London ).

            Maybe since then it had flattened off, we shall see ( or someone has the data to share here ).

            Part of this increase is due to an increase in population.

            I would welcome more use of public transport and cycling ( or walking ), but the convenience of a car will continue to drive up the number of cars on the roads it seems.

            We can look forwards to more electric cars, or maybe hydrogen powered ones. Good to see bp investing in charging points at their petrol stations.

      • Friday’s “quake” in Newdigate measured minus 0.7. That’s almost 1000 times less powerful than a quake that measure plus 2.0. The one prior to that meaured minus 0.4.

        A quake of plus 2.0 would be deemed minor and indeed only very few people would notice it, even if they were on top of the epicentre and it was shallow. You might see liquid in a glass ripple or feel a very light vibration, but that is really the extent of it.

        Mother nature has been producing earthquakes and micro earthquakes (those measured as 2.0 or less) for billions of years. Indeed take a look at the last 50 days’ quakes across the UK…

        ….they happen all over the place…many with greater intensity and in places where no O&G activities are taking place!

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