UK: Oil company says “We’re not to blame for Surrey earthquake” – but local concerns remain
A few comments first to the article included below
Dorkinian
April 4, 2018 at 10:46 pm
Well the usual posters (investors?) are here again claiming there’s nothing to see, as usual. Why are they always on here then? Keith Taylor is right though to say it’s a larger earthquake than the ones Caudrilla caused when they Fracked Preese Hall-1. Earthquakes in Surrey are almost unheard of and this one is 3 kms from the Horse Hill drill site. Yes it could be purely coincidental but what is there to fear from an investigation into local faulting? The smaller earthquakes in Lancashire resulted in a moratorium. If the drill site is connected by a fault to the earthquake epicentre we need to know, and if the extensive acidisation of 2016 caused this movement now the consequences will be widespread. There is more at stake here than sparing the blushes of a few AIM investors.
the worm forgives
April 5, 2018 at 5:42 pm
If the Epicentre is where it is estimated to be (could be several kilometers out) and at the estimated depth (it may be as deep as 8km or as shallow as 3km), we may be talking about seismic activity in the Collendean fault (or directly below it) – a fault through which UKOG intend to drill this year.
There is something odd about this. The Horse Hill geology is claimed to be a lookalike for the Broadford Bridge geology. Approximately WNW of both sites there has been seismic activity: at HH 4km away on April 1st; at BB 6km away in 2005. At both there are deep faults running E – W just to the north of the wellpads. The well bores are aimed at and through these faults. At BB1 and 1z, washouts occurred at or near the fault system.
Washouts are often caused by seismic stress. The flow test at HH ran out of time. The BB flow test ran over considerably due to integrity issues.
I am not convinced that the semi-conventional techniques used at these sites are suitable for this challenging geology.
I certainly wouldn’t be comfortable knowing that sites in the area were re-injecting produced water into older wells which cut through active fault systems
Also, is a recently active fault more likely to allow movement of hydrocarbons from the deeper sources? If so, does that indicate that our famous low sulphur, mobile light oil may well have come from deeper than the Kimmeridge Shale in which it sits?
the worm forgives
April 5, 2018 at 9:22 pm
You will find lots of info on the borehole problems caused by fault stresses in this publication. You will note the line of stress-induced problems across the UK from the Weald through Lancs up to the Shetlands in the second map:
Understanding tectonic stress in the oil patch: The World Stress Map Project by
MARK TINGAY, BIRGIT MÜLLER, and JOHN REINECKER, Heidelberg Academy of Sciences, Karlsruhe, Germany OLIVER HEIDBACH, FRIEDEMANN WENZEL, and PHILLIP FLECKENSTEIN, University of Karlsruhe, Germany
Dorkinian
April 6, 2018 at 8:36 pm
Shalewatcher, do you really think the Kimmeridge is a conventional target? I’ll give you the benefit of the doubt and offer you this highly informative film where you will learn how to tell unconventional from conventional. https://youtu.be/hxoBMzMUo_c
We heard all the same denials after the Preese Hall-1 shocks but the fracking induced earthquakes there crushed the steel drill pipe and the well had to be abandoned. Presumably the acid stimulation carried out at 3 depths at Horse Hill in 2016 was supposed to be at sub fracture pressures but confidence in these operators is understandably low.
Malcolm Kenward
April 4, 2018 at 5:02 pm
The BGS are “unable to say” and yet UKOG are definitive in their denial. It is not unknown for earthquakes to occur after oil/gas extraction whether from conventional or unconventional sources; one is removing something from deep underground, and therefore potentially creating voids. And in a heavily faulted area such as The Weald, it might just be that a small change deep down could lead to earthquakes. Just imagine how much oil and associated materials would be extracted at Horley if it went into production. It is too early to dismiss a possible link to UKOG activities, but it surely warrants further investigation, rather than dismissing out of hand. After all, we’re supposed to have world class standards, so we’re repeatedly told.
Katherine Berwick
April 4, 2018 at 5:18 pm
Given current evidence in this country and other places globally, I cannot understand why UKOG should view this as a ‘malicious connection’. What concerns me more, is has the seismic activity in the area possibly caused damage to the existing well at Horse Hill and if this is a possibilty, this has to be of major concern to local residents and the environment.I hope UKOG are going to check the well for any signs of damage and re assure the community and beyond that no harm has yet been done.
Phil C
April 4, 2018 at 5:41 pm
Oh the joys of self regulation and crippled regulators failing to monitor and record?
If there were such evidential records, it does not take much imagination to assess just how long it would take before the shredder had another impromptu meal?
Paula Cooper
April 4, 2018 at 8:27 pm
I don’t think it’s alarmist to expect an oil company to check well integrity after seismic activity. That’s gold standards. I agree any company that may have pipework under and overground should also check. I certainly don’t feel my opinion is malicious just prudent.
Oil company says “We’re not to blame for Surrey earthquake” – but local concerns remain by Ruth Hayhurst, April 4, 2018, Drill or Drop
The oil exploration company, UKOG, says there’s no connection between its drilling site at Horse Hill near Gatwick Airport and the Easter earthquake in Surrey.
The 2.7 magnitude earthquake on 1 April was centred on the area around Newdigate, west of Horley, and felt by people living near Horse Hill.
It was seven years to the day after an earthquake in Lancashire, which was later linked to fracking by Cuadrilla.
But UKOG, the leading investor in the Horse Hill site, told DrillOrDrop this afternoon that there was no link between oil exploration and the earthquake. In a statement, the company said:
“We strongly refute the far-fetched, unscientific and malicious connection made between Horse Hill and the earthquake in Surrey on April 1st.
“There is no drilling, testing or underground works taking place at Horse Hill or at any of our sites at present. All such work at Horse Hill ceased over two years ago.”
Oil exploration across the Weald in southern England has attracted criticism for the use of acid in wellbores. Companies have argued that it is a standard oil industry technique to clean the wellbore and stimulate the flow of oil from surrounding rocks. But opponents have said it is the equivalent of “fracking under the radar”.
The site operator at Horse Hill has planning permission to use acidising in operations to test the flow of the well.
… The British Geological Survey (BGS) told us it was well-known that induced earthquakes could be caused by activities including hydrocarbon exploration and production, waste disposal, mining and geothermal power generation.
Brian Baptie, a seismologist with the BGS, said:
“In the case of the magnitude 2.7 ML near Newdigate, Surrey, on 1 April, we are unable to say if this event was caused by hydrocarbon exploration or production mainly because of the uncertainties in our estimates of the earthquake epicentre and depth. We used a process a bit like triangulation to locate earthquakes and our closest monitoring station was over 70 km away, so the errors in our location estimate are several kilometres.
“I believe there is no current drilling or testing at the Horse Hill 1 site. The LR/24- 4 well was drilled in 2014 and well testing was carried out in 2016. Similarly, I believe that all oil production at the Brockham field, just south of Dorking has been conventional and there has been no hydraulic fracturing or “fracking”. We have not recorded any seismicity associated with this field in the past.
“Background levels of earthquake activity in this part of England are very low and I believe that this is the first earthquake that we have recorded in Surrey since BGS started instrumental monitoring in the 1970s.”
…
The British Geological Survey (BGS) told us it was well-known that induced earthquakes could be caused by activities including hydrocarbon exploration and production, waste disposal, mining and geothermal power generation.
Brian Baptie, a seismologist with the BGS, said:
“In the case of the magnitude 2.7 ML near Newdigate, Surrey, on 1 April, we are unable to say if this event was caused by hydrocarbon exploration or production mainly because of the uncertainties in our estimates of the earthquake epicentre and depth. We used a process a bit like triangulation to locate earthquakes and our closest monitoring station was over 70 km away, so the errors in our location estimate are several kilometres.
“I believe there is no current drilling or testing at the Horse Hill 1 site. The LR/24- 4 well was drilled in 2014 and well testing was carried out in 2016. Similarly, I believe that all oil production at the Brockham field, just south of Dorking has been conventional and there has been no hydraulic fracturing or “fracking”. We have not recorded any seismicity associated with this field in the past.
“Background levels of earthquake activity in this part of England are very low and I believe that this is the first earthquake that we have recorded in Surrey since BGS started instrumental monitoring in the 1970s.”
Refer also to:
2011 10 15: Drilling bv Cuadrilla did cause ‘earthquake’
“Any suggestion of an acceptable level of earthquakes caused by fracking should be rejected. The Government must realise it must stop treating our communities like guinea pigs and accept these techniques carry unacceptable risks to the British public.”
2011 11 03: Frac company Cuadrilla – we caused 50 tremors in Blackpool – but we’re not going to stop
Perhaps another coinsidence?
https://dwarshuis.com/earthquakes-groningen-gas-field/visualisation/
[Above link to MUST WATCH visual, stunning damages caused by gas industry’s quakes]