“Gatwick Gusher” breached safety laws over blowout preventer

1810 Horse Hill UKOG2

Horse Hill oil site near Gatwick Airport, October 2018. Photo: Used with the owner’s consent

The oil exploration site in Surrey, nicknamed the “Gatwick Gusher”, breached health and safety laws last year, DrillOrDrop has learned.

The site was issued with a formal notification and ordered to pay a fee by the Health and Safety Executive (HSE).

An inspector had found problems with the set-up of a critical safety device designed to prevent the uncontrolled escape of well fluids or gases from deep underground to the surface.

Horse Hill Notice of Contravention (pdf)

The inspector recorded material breaches of the law against the site operator, a subsidiary of UK Oil & Gas (UKOG), and ordered the company to make changes.

UKOG told DrillOrDrop “all matters were quickly and satisfactorily closed out with HSE”.

But Brockham Oil Watch, the campaign group which uncovered the breaches, said they showed the importance of active monitoring by regulators.

The HSE reported the breaches after a site visit to Horse Hill in August 2018, during extended well tests.

Five months earlier, the Oil & Gas Authority had asked UKOG for evidence of the technical capability of the site operator, HHDL, to carry out the tests.

UKOG is currently applying for planning permission to drill four more oil wells at Horse Hill and carry out long-term production. The latest public consultation on the application ends on Monday 24 June 2018 and a decision is due in September.

The Horse Hill notification of contravention was included in correspondence between the HSE and UKOG. This was released in response to a freedom of information request by Brockham Oil Watch. The HSE does not routinely publish these notifications.

1810 Horse Hill UKOG1

Horse Hill oil site near Gatwick Airport, October 2018. Photo: Used with the owner’s consent

“Inadequate means to handle well control problems”

One of the breaches concerned the blowout preventer on the single existing well at Horse Hill.

Blowout preventers are pressure control systems that usually comprise a large valve at the top of the well. This can be closed immediately if a drilling crew mis-manages the density of drilling fluids in a borehole, and loses control of formation fluids.

The Deepwater Horizon oil disaster was caused by a wellhead blowout, and took several months to bring back into control. DrillOrDrop understands that the size of a blowout could be small in the Weald. But a so-called “Gusher” is a well where oil and gas come to the surface without being pumped, driven by pressure of gas separating out from the oil.

In a letter dated 6 September, the inspector wrote to HHDL:

“The configuration of the blowout preventers (BOP) does not provide adequate means to handle potential well control events as required by the current API standards 53.

“While it has means for closing and sealing the wellbore on the work string and on open hole, it does not have means for stripping in the work string.

“The arrangements you have in place for kick [well pressure control problems] detection during tripping and circulation operations cannot provide sufficient assurance for an effective detection of anomalies of well parameters.”

Well integrity test concerns

The inspector also raised concerns about a well integrity test, the checks designed to ensure a well is not leaking or that there are no uncontrolled releases.

The notification of contravention said:

“With reference to the well integrity test report …. there is no evidence to suggest that there have been checks on the pressure and the integrity of the wellhead voids.”

The notice also recorded that the well handover form/certificate did not “contain all the necessary information as recommended by the UK Oil and Gas Guidelines”. It continued:

“It does not contain the number of turns required to close and to open the manual gate valve, the status of the annulus gate valves and well head voids.”

181220 Horse Hill site plan HHDL

Site plan for the proposed extension to the Horse Hill oil site in Surrey. Source: Horse Hill Developments Ltd

Instructions and advice

The failures represented a material breach of the Offshore Installations and Wells (Design and Construction etc) Regulations 1996, the inspector wrote.

The site operator, Horse Hill Developments Ltd, was instructed to carry out a risk assessment of the configuration of the BOP and act on the results.

It was also ordered to ensure:

  • Sufficient and effective arrangements to detect kicks
  • Well handover certificate had all necessary information
  • Integrity of wellhead voids were checked regularly as part of well integrity tests

The company was ordered to display the breach notification to staff and to pay a fee to cover the cost of the HSE visit.

It was also advised to revise:

  • well planning design and operations standards to incorporate current industry standards and best practice
  • a safety document to reflect rig-less well testing operations
  • risk assessment and well shut in procedures to make them more specific to reflect arrangements and equipment

The inspector also noted there was a risk of corrosion from topping up the annuli (void spaces between the tubes running up or down the well) with fresh water. During production, injection and suspension the annuli should be filled with inhibited fluids, the inspector recommended.

The FOI response included correspondence from HHDL to the HSE in October 2018. In it, HHDL said it had carried out the risk assessment and was reviewing operations and procedures.

Horse Hill response to Notice of Contravention (pdf)

A separate FOI request revealed that in March 2018 the Oil & Gas Authority asked UKOG to respond to a series of questions about HHDL’s ability to carry out the extended well test. They included HHDL’s in-house technical capability, its corporate and governance structure, arrangements to respond to unexpected events and financial capacity.

Company comment: “all matters quickly and satisfactorily closed”

A spokesperson for UKOG said:

“As requested, Horse Hill Developments Ltd responded to the letter from the Health and Safety Executive on 3rd October 2018. A risk assessment of the Blow Out Preventer was completed, and all matters were quickly and satisfactorily closed out with HSE. The wellhead voids had in fact already been inspected as part of our well integrity checks. There were records to this effect on the Horse Hill well site, which unfortunately were missed by HSE’s inspector on the day. This routine HSE visit to the Horse Hill site in August 2018 was considered by both parties to be successful. It should be noted that there was no comment on the Blow Out Preventer arrangement from HSE during their original regulatory review, prior to the commencement of operations.”

Reaction: “Highlights importance of active monitoring”

The campaign group, Brockham Oil Watch, which uncovered the breach, said:

“This breach demonstrates the importance of site visits and active monitoring by the regulators.

“Yet, according to responses to our FOI requests, which covered the period from 1 March 2018 to 15 April 2019, this was the only HSE visit the Horse Hill site. In February this year, the Environment Agency told us that their last visit to Horse Hill was in August 2018.

“These visits are too few and far between; all too often this inherently dangerous industry is left to self-monitor and self-report. In particular, the so-called “conventional” sites, where operations don’t qualify as “associated hydraulic fracturing”, normally receive less scrutiny and are subject to lower reporting/monitoring standards.

“We were told that the Notice of Contravention would not routinely have been shared with other regulators, or any third parties. The only reason it is now released is because someone asked the question. This lack of transparency on a serious issue doesn’t seem to serve the public interest.”

Application decision

The application for long-term production and additional wells at Horse Hill is expected to be discussed by the Surrey County Council planning committee on 11 September 2019. Link

This is the latest postponement of the decision, which had previously been scheduled for March, April and most recently July 2019. Surrey County Council has reported there have been at least 1,000 objections to the proposal.

DrillOrDrop page on Horse Hill

Updated 21/6/2019 to change “broke” to breached” in the headline

72 replies »

  1. They can’t be trusted in any way, cowboy company. I expect this to be taken into account at future planning applications

    • Hi Jono – have you ever read API53? If you have and you check most major oil companies outside the USA you will find that they do do not fully comply with API53. But I assume you know what API stands for?

      As for the DOD article attempting to exhibit knowledge of BOPs / Deepwater Horizon in GOM / and the HSE Notice issued to Horse Hill there is clearly a complete lack of understanding of all the issues raised in the HSE Notice.

      Another none story trying (hoping?) to rally the antis…..

            • Sorry PhilC – your wasting your time. Perhaps someone else on here may understand where you are trying to go with this?

              But no doubt there are some who have missed you.

              • Meanwhile, back in the real world-Remember all those past comments about secure energy supplies for the UK?

                Gulf looking very secure at the moment. UK tax potential being exported to the region for more arms to be purchased instead of being utilised in UK, including 6% from UKOG.

                Maybe a few more yellow vests will emerge in Paris as energy prices go higher there as well.

              • You still here? You missed a beautiful day in glorious free sunshine. Didn’t cost a penny.

                But you keep missing me Paul, there again, fossil fuel accuracy was never exactly a strong point was it? About 500 million years out of date in fact.

                Never mind, better luck next time….

            • Phil c stop with the nonsense, would you like a saying which is of your own and not rehashed! You then loose credibility and no-one cares! I’m out!

              • Fascinating isnt it ladies and gentlemen, boys and girls, looking back at the recent posts of Eli (Extinction Level Intellect?), clearly Eli likes to make the most outrageous nonsense comments on Drill or Drop, and yet cannot handle a little wisdom from those who could teach so much?

                Apparently there are those who are lost in more ways than one….?

                Never mind, here are some of my own words for those who cannot handle the wisdom of others…

                “Only an angry person sees anger in another.”

                “To those who know only nonsense, anything sensible, is merely more nonsense to them.”

                “Those who judge others by their own standards, merely reveals how low their standards are”

                Have a nice Sun-day….

    • The article just seem more irrelevant nit-picking from someone who seems to have a grudge against the petroleum industry.
      We all know that interpretations of subsurface data have massive amounts of uncertainty but this generally doesn’t impact HSE, which is the main issue that the planners need to discuss. I’ve been involved in a large number of projects where we have to drill based on surface mapping and grav-mag data with no seismic and it didn’t have a significant impact on HSE. In places I worked such as PNG, Austrian Alps, Bolivia etc, the geology has been so incredibly complex that we know that are interpretations of the subsurface are going to be wrong – it doesn’t make any practical difference to the HSE. I’ve working on subsalt prospects where we have drilled through faults with a km throw and again it doesn’t impact HSE.

      The two key HSE issues that you bring up are the use of acetic acid vs. 15% HCl or the prospect of induced seismicity. Dealing with both HCl and acetic acid is trivial. The rate of reaction of both acids with CaCO3 is so fast that they represent no significant danger when injected to the subsurface. The idea that seismicity in this area has anything to do with activities in HH-1 has been totally rejected by anyone with any competence in seismology or geomechanics who have examined the data. Furthermore, there is no theoretical mechanism to explain the link between activities in HH-1 and seismicity. Simply put, the volumes of fluids injected and the pressure changes at the borehole are far too small to be of significance. I write this as someone who firmly believes that pore pressure changes in boreholes can affect production rates and induce seismicity at a significant distance (i.e. in excess of 10 km) from the point of injection/production. However, the injection/production rates were many orders of magnitude higher in the cases where this has been observed than have occurred in HH-1.

      The fault-core damage zone model that you present to explain the fall in production rates in the well cannot be discounted. However, this model mainly works for faults in rocks that are at a low stress compared to their apparent pre-consolidation pressure. This is probably the case for the limestone layers (you are wrong to argue that micrite is not a form of limestone) but certainly not in the more clay-rich units that dominate the Kimmeridge clay formation.

      Overall, your “paper” seems to be attempting to undermine the credibility of UKOG. It may indeed have that effect on planners who know little about the petroleum industry. However, those of us who have spent our lives working on these issues will see it for what it is – totally irrelevant.

      • Hi Simon. The use of chemicals including acids is regulated principally by the EA, not HSE. Also, how do you know what the volumes of fluids and injection rates are at Horse Hill? The regulators are not monitoring this.

        • BOW – if it’s not viewed as an HSE issue there is even less to worry about. I could see a few issues with staff handling the acid – although 15% HCl is generally OK – I’ve often spilt 20% on my hands with no impact. It definitely won’t be an EA issue due to the rapid rates of reaction with calcite (at room temperature 15% HCl equilbrates with calcite in about 5 minutes and reaction rates increase with temperature). I know the volumes of fluids and injection rates because someone involved with reviewing the seismicity asked my opinion on the subject; in a previous job I managed a project which developed a fully coupled thermohydromechanical finite element model for investigating the link between fluid pressure changes and horizontal stress, as well as fault reactivation due to fluid injection.

          • What I meant is that the volume and pressure data is not available anywhere. It’s not reported to the regulators so they don’t have it. So any such data would have to come from the company and the regulators could not verify it.

          • Simon – not sure why one would need any complicated software for this – a simple material balance calculation combined with knowledge of the permeability and volume of fracture systems would show that it’s not possible for the earthquakes to have been caused by the production/injection. I’ll send you with a spreadsheet that Mike developed to do these calculations. It’s back of the envelope stuff but seems to work

            • Judith, I didn’t actually say that I needed to use the TMH code for this problem – I just mentioned that I read a lot about fluid injection and seismicity when I was managing a project. I agree that this is a trivial problem – I didn’t even put numbers into a spreadsheet – the only reason we are even discussing it is that people who know nothing about this subject have raised it as an issue.

        • Shutting down all global warmers,
          Oh well shiranne that will be only 700 million people left in this supposed apocalyptic post fracking world, that sounds like a dream to me, less people and less world problems!
          Sherwolf Really helpful comment, NOT!

          • Eli-G, on the positive side, they do seem to have condensed their rubbish into a few words instead of the usual novel of nonsense.

          • Not sure where you got your numbers from, the post quote ‘over 7 billion’…

            And not sure you should be advocating mass destruction so you can buy another yacht?

            Am afraid it would be more of a nightmare as no human will survive this destructive path created by those who knew the risks many years ago; yourself included?

            Fracking is finished; oil and gas next.

            And it will happen, though this will take time as cutting it now, which would be the best option, would be akin to hitting a brick wall at seventy miles an hour. Our society is too infiltrated by the tendrils of greed and laziness – yes that means all of us. We have to apply the brakes and gear down quickly, it has to be done now. The joy ride is over folks, time to get back to real life.

            Clearly a helpful comment Eli as you and Judith who is not Judith have reacted with your usual childish response; no credibility there; jog on 😉

              • Sherwulfe
                Good to see the owner of the power lines planning to manage the transition from large power stations to a distributed system, with less large producers, and a more variable generation.

                I am sure that smart meters will turn up somewhere in the mix. But they have plenty to do before that.


                Meanwhile the gas distribution system ( something NG sold off ) soldiers on, thinking about how it could convert to hydrogen at some time in the future.

                • hummm…they said the same about mobile phones, microwave cookers and rivers near to Sellafield……

                  There is a huge turn in the wave which has come to the fore, not because we are about to annihilate ourselves, but because the money lovers are afraid they will lose their lazy wages; still, better than noting at all I suppose.

                  I wonder if the yacht owners know that when the infrastructure goes down through conflict over food, the computer generated money goes with it? I hope they know how to find clean water and forage for food!

            • Shiranne there are 7bln 700mln peole estimated on earth! Go figure… credibility is what i am good at thanks, at least i have an education in the oil, gas and energy industry with environmental science. And Gas production is a positive, you my darling are a socialist of the highest order and that is the danger of not understanding how the captains of industry keep our lights houses warm, flights fueled and cars on the road, oh and a pay a damn sight more tax than you!
              Governments love them and why not! P.S. who do you think contribute the most and the majority of todays stock market OAP pensions, taxes and other than financial. The Oil, Gas and utility companies!

  2. Yep, Joseph, and also do the same for the wind turbines before one of those falling down or exploding causes a fatal incident.

    Better get rid of all the Teslas on the same basis, except it would be after not before.

  3. Hmm seems a case of HSE moving the goalposts quote (. It should be noted that there was no comment on the Blow Out Preventer arrangement from HSE during their original regulatory review, prior to the commencement of operations.”)

    • Appaently the BOP arrangement was fine – it was the lack of a risk assessment (paperwork) which was the problem. Assuming there was an annular stripping in / out can be done.

      • Paul Tresco

        Looking at the company reply, they bought two annular preventers in order to comply with the findings of their risk assessment, for annular to annular stripping. But without a picture of their set up for rigless operations we may only infer what they had in place before.

  4. Not been active in oil and gas, gasman, but my experience in other sectors is that HSE checks are open to some individuals being more pedantic than others. Bit like footy refs.-the rules are standard but individuals are different.

  5. The truth comes out – in the Guardian of all places:

    “At the current growth rate of real jobs in this sector, you wouldn’t bet on that figure of 130,000 being reached before that big asteroid with Earth’s name on it finds its bearings.”

    “UK taxpayers are entitled to ask why they are paying fortunes to subsidise green energy and create jobs everywhere else in the world except here. By 2022, all UK energy bill payers will be paying an extra £500 a year for renewables. EDF and the other global firms that have filled their boots on Scotland’s energy potential will make a lot of money from this. Gary Smith, secretary of GMB Scotland, said: “The electricity produced by this work will be very expensive. As a society, we are entitled to insist that the jobs created should be made here in Scotland.””

    • I am gob-smacked you still bring money into it when the human population is about to leave the earth because of the few…..

      As money does not actually exist and is just a fleeting number on a very vulnerable computer, perhaps it’s time to redistribute and do the right thing?

      • Actually the Guradian / Observer wrote the article – not me – but thanks anyway for the credit. It is about being ripped off under the umbrella of “green”. Expected in England but not in Scotland under the SNP.

        • So if I put a link to an article, and particularly a quote, it is reinforcing my opinion….maybe you just use quotes for the hell of it?

  6. The Boris-like ignorance of pros standing up for industry breaches is satisfying to see. HHDL use inadequate safety procedures but yet HSE are deemed to have ‘moved the goalposts ‘. Everytime you guys open your mouths you demonstrate to local people your arrogant disregard for anything other than your own self-interest. No wonder opposition is growing so quickly. Please carry on as you are. Your investments are in a dead duck :0)

    • Doctor Dave – we don’t have any self interest other than the desire to see the UK produce it’s own energy. Most of those who are for shale gas extraction simply don’t want to see a totally safe industry closed down due to the actions of NIMBYS and those who have no understanding of the subject.

    • I blame the lap dancing club in Glasgow that has introduced union rights for its employees, including health and safety! Maybe Horse Hill not such a good gig for the HSE.

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