Bishop Hill Fracktion
Sep 5, 2013 Energy: gas Readers may be aware that Cuadrilla have decided to suspend drilling operations in Balcombe and will seek new planning permission. As one might expect this has prompted the usual slightly crazed round of accusations and innuendo from the green fringe, but there are slightly better quality critiques around.
Professor David Smythe, a retired geophysicist (and formerly the bass player in the Rezillos!), has written a critique of Cuadrilla's plans from his home in the South of France. You can see it here, with an article directly addressing Cuadrilla's decision to suspend operations here at the Greenpeace site. (I'm not sure this choice of outlet is a wise move on Prof Smyth's part, at least if he wants to be taken seriously).
The critique has several different points of attack: that there are more faults in the way than Cuadrilla are saying, something he says is distinctly different to US shales where he says there are none, that Cuadrilla won't be able to keep their drill in the oil-bearing layer, and that if they drill into a fault then there is a risk of leakage and or earthquakes.
In response James Verdon has pointed out a few problems with Smyth's critique. They are quite big problems actually.
- The areas where Smyth is saying there are more faults are outside Cuadrilla's licence area
- There are faults in US shales too
- Drilling technology has moved on since Prof Smyth's day and it is now possible to detect what kind of rock is being drilled and to steer the drill bit.
- and so on.
Reader Comments (38)
Verdon's critique covers both those objections I knew and imagined to be true. "I'm not sure this choice of outlet is a wise move on Prof Smyth's part, at least if he wants to be taken seriously" - more likely he wanted the activist fringe to take him seriously. Apparently.
I like this trend of outing people who used to be in bands - a lot.
My tips - I reckon that Rog Tallbloke used to be in Fairport Convention, while Marc Morano was the fifth Ramone.
Verdon's critique of Smythe stands up.
I don't know where Smythe got the idea that US shales don't have faults. All rocks have faults. In sediments, faults develop as they accumulate, and can be imposed at any time afterwards. They may or may not be active. It all depends on the stress field.
Not all geophysicists are created equal. Within the field there are specialists in gravity, electric, magnetic and electromagnetic methods, as well a seismic. I'm not sure of Smythe's backgound, but it may well not be seismic.
Smythe descibes the Kimmeridge clay as "shale". I'm not sure that at a burial depth of less than 800 metres that will be valid. Unless it has been buried a lot deeper than that it is unlikely to be lithifed, and therefore not "shale". FWIW, micrite is a contraction of microcrystalline calcite. It's a limestone and should show up very nicely in the seismic. thinkingscientist should be along shortly to straighten everyone out, including me. He's an active practitioner.
johanna: Which greens used to be in Jefferson Starship? :-)
I don't know why the greens are being so fracktious about fracking, there are over a million wells in use at the present time, if there were any serious problems they would have been on the front page of every newspaper in the country and lead story on the BBC Green News.
Dave Smythe was in The Rezillos for sure - for a couple of years or so I think. I met him once when he was at Glasgow University although I never had him as a lecturer.
I wish the opponents of fracking would stick with their real reason for opposition to fracking: The fear that renewables will be abandoned. These irrelevant side issues are mere distractions from the real debate.
Eny fule kno that these exploration companies drill recklessly and needlessly: goodness knows how they survive. Get a Green on the board of directors and they could save a fortune.
Private Eye's latest edition continues it's obsessive anti-fracking campaign in several articles . It really has become virtually unreadable.
artwest - I agree. As a long time reader I am beginning to think about cancelling my subscription as the rest of the content is proceeding rapidly downhill too. Hislop needs to look long and hard at the magazine, or perhaps the problem lies with his attention being elsewhere.
JamesG (Sep 5, 2013 at 9:23 AM):
I think you’ve hit the nail on the head, there.
Artwest (Sep 5, 2013 at 9:29 AM):
I have noticed that myself; however, with the editor’s apparent political inclinations (strange, considering his background… …or is it?), perhaps we should not be too surprised. What did interest me was the article about radioactive waste raised during drilling; it was the first time I had heard of this. What amount are we talking about, and how much above background level can it be?
(As an aside, I remember the delicious irony of Manchester declaring itself “nuclear free” in the 1980s(?), ignoring the many public buildings in the city made from granite.)
Johanna: "I reckon that Rog Tallbloke used to be in Fairport Convention, while Marc Morano was the fifth Ramone."
It's true that I do play/sing some folky stuff I write for fun. But for a while I was rhythm guitarist for a local rock and blues outfit, which knocked out some great AC/DC, Johnny Kidd, and Jimi Hendix covers.
Well if David Smythe is entirely right Cuadrilla will have drilled a dud. So what? Is he a share-holder? If not, it's of no importance to him. Or does he want a slice of consultancy?
Some knowledgeable folk have already picked up various technical issues with the Prof's comments.
What struck me was the general tone, treating Cuadrilla as incompetents and/or deceivers. He also criticised their fault line analysis outside the Balcombe area while admitting that, within the area, it was OK. The surface fault "might" intersect the well...but, if so, that would be known from the original drilling. And so on.
Most significantly, I did not see mention of any attempt at communication with Cuadrilla. Surely the reasonable, professional approach would have been to contact the company first. Had he done so, either his concerns would have been addressed or he could feel justified in going public with the correspondence.
Heh, Roger, you look a lot like, and remind me of, my high school science teacher. We thought he was really cool (in the early 70s) because he had long hair and a beard and played in folk and blues bands. He was also passionate about science.
I saw him a while back and he is just the same, except for the colour of his hair and beard. He gave up teaching in his late 30s and became a world famous practitioner of, and authority on, an obscure (to me) type of Japanese pottery. He went to live in the country and set up a pottery business there, while playing a bit of music on the side. But he still keeps up with a wide range of scientific interests.
So, there are at least two of you in the world!
Radical Rodent.
Any rock with potassium minerals will be radioactive. There are many. The soil in your garden is radioactive. The food you eat is radioactive (best example is the banana)
Short story. About 15 years ago, in another life, I drove out to a uranium mine in the Cooper Basin in South Australia to collect a set of drill samples taken through the uranium ore body. I took them back to base (CSIRO, Floreat Park). When I got back, I phoned the site safety officer and told him I had some radioactive samples and asked him to check them out. He duly arrived with his geiger counter, and had a good laugh. He put the geiger counter on the bricks of my office wall and got a higher reading than the uranium samples on my office floor.
The buildings we live in are radioactive. The soil we grow out food in is radioactive. The food we eat is radioactive, and the cuttings that come out of the drill hole are radioactive. This is a classic GreenScare(TM).
mikeh
Greens have no conception about being professional. They assume that everyone is as disorganised an unprofessional as themselves. This is part of their projection.
I commented at Verdon's site. I was shown this article by Smythe a couple of weeks ago and it is full of holes. If Smythe were correct that "faults don't normally seal", then many, if not the majority, of oil and gas fields couldn't exist. Its a patently absurd statement from a geophysicist and completely blows his credibility.
As someone in the business who knows this stuff pretty well, he is talking largely bollocks. The concept of sealing faults is fundamental to creating an oil or gas trap in many fields. Without fault seal, no traps in many, many cases. Fault seal is not rare at all. The map of closure around Bolney-1 shows a typical working assumption of fault seal: the red area clearly follows the faults, indicating they are assumed to be sealing. I design and sell software for analysing volumetrics of oil and gas fields which contains a model approach for including the affect of sealing faults on volumetrics. His claim is just absurd.
Also, his suggestion that the fault interpetration doesn't agree with the BGS surface mapping...well so what? All these things are interpretations and the BGS may not have got it right. Cuadrilla have their seismic data and they are free to interpret it as they think best. Thats what exploration is all about.
Regarding "fast track conduits to the surface for...released methane." Well Prof. Smythe there is news for you. This is a basin with an active petroleum system and the aquifer is already naturally contaminated by natural gas. This was known when Conoco drilled the original Balcombe well in 1986 and is also shown on the map of Bolney-1 etc where one of the shallow boreholes is marked as "gas shows" (next to the horizontal blue line on the right of the map). These Southern basins are leaking hydrocarbons at lots of places: Osmington Mills, Burning Cliff, Lulworth Cove (see http://www.southampton.ac.uk/~imw/jpg-Petroleum-Geology/10PTS-Stair-Hole-Wealden-Oil.jpg, image taken from the excellent article on the geology here: http://www.southampton.ac.uk/~imw/Oil-South-of-England.htm)
.
David Smythe's title is a courtesy, he has been retired since 1998 from being a Professor at Glasgow University. I note that Prof. David Smythe has taken a strong position over UK Nirex nuclear repository location work in Cumbria (see here http://www.davidsmythe.org/nuclear/nuclear.htm). I know something about that topic too, I worked on it as a consultant for nearly 4 years in the 1990's...some employees of the BGS tried to pass off geophysical work I did as part of that consultancy study as their own. That was quite funny, when they approached the oil company I had joined after the consulting. with a proposal that I was asked to review...that contained my own data and results. LOL.
Verdon's critique is spot on and accurate.
PS I see on BBC South news this morning that environmentalists are objecting to Perenco continuing with Wytch Farm. 190 wells over 30 years, they have fracked there for years, nobody in even noticed. No environmental damage.
Oh, Lord! Will this madness never end? (Oooh! Can I copyright that?)
I am afraid 'thinking scientist' that the greens are not open to rational argument at all. The ''One Show'' visit, with a geologist, said it all,-- they were not listening to him one iota.
We need the energy and fracking has been carried out in the UK since the 60's with no one noticing. Earthquakes may, or may not, be caused by fracking, the BGS report actually contained a lot of 'mays' 'coulds' 'mights' so even they do not have real proof. Many faults remain hidden and so unknown which the recent Lincolnshire earthquake proved. Lincolnshire has many fracked wells done years ago but the last quake fault did not come to notice then so probably that fault had just got to the slip phase at that time. Nothing to do with fracking.
Firstly, Prof Smythe seems to have quite a lot of form as an environmental campaigner. Here he is opposing underground nuclear waste disposal
http://www.davidsmythe.org/nuclear/nuclear.htm
Secondly, turning his opprobrium towards Cuadrilla and the Balcombe prospect seems to owe more to his emotional green proclivity than his scientific rationality. The Balcombe subsurface seismic interpretation is a thoroughly humdrum and totally mundane example of a typical exploratory prospect seismic subsurface structural interpretation and how it might differ from alternative interpretations. I spent my whole career developing and evaluating the geological potential on interpretations and drilling results on prospects similar to this. It always requires the drillbit to verify reality, even with 3D seismic coverage. 3D seismic is costly, particularly onshore, and usually only justified for confirmed discoveries. The fearmongering about fault leakage is so out of order that it would, if taken at face value, close down petroleum exploration on just about any prospect, anywhere. The concern about the horizontal leg wandering out a the micrite bed into the Kimm shale is emotive nonsense- both together obviously comprise the entity of the low permeability host reservoir target on which a frac stimulation is hoped to achieve commercial flow rate productivity if natural fracture permeability is absent.
Very nice ThinkingScientist and Pharos. Pharos, I didn't know you were a geo(whatever) too. Geos (along with engineers) seem to be over-represented in the non-alarmist ranks. Speaking for myself (sedimentologist), its because I know history, and there's nothing new to be seen here.
Hector Pascal
So who exactly are all these people that the politicians are actually listening to (see the 'Dairy date: persuasion' thread)?And more importantly, why?
Prof Smythe also is obviously unaware of the developments in current geosteering technology, which enable the horizontal well placement to be made far more precisely than would be possible by the 20 meter vertical resolution of 3D seismic. Modern horizontals are steered in real time as they are drilled by measuring the local petrophysical properties azimuthally in terms of resistivity, (Hydrocarbons resistive, salty water conductive), acoustic and nuclear response from the rocks (To both the natural potassium content and the response to neutrons) following either the hydrocarbon contact, or the geological context. Wells can be steered +/- a meter for up to 5 Km.
A little bit about petrophysical logging and horizontal wells-
Traditional wireline borehole logging involves tripping out of the hole with the drill string, then lowering single, or more commonly a combination of sophisticated sensor tools one on top of the other down the hole on a cable, to evaluate the characteristics of the penetrated rock sequence- its structural orientation relative to the borehole geometry, depth, the rock fabric its lithological composition, porosity, sonic velocity, density, electrical resistivity and the presence of/hydrocarbon saturation of formation fluids in potential reservoirs of interest encountered by newly drilled section of open hole below the lowest earlier log run, which ended at the uphole casing shoe. The log data from wells provides the principal archive source for all petroleum related detailed geological subsurface interpretation work- correlation between wells, structural mapping, depositional environment interpretation, etc. Although all petroleum geologists need to be well versed in log analysis, a dedicated specialist log interpreter is known as a petrophysicist.
This logging technique will not work in highly deviated or horizontal wells because you can't push on a cable. With the advent of commonplace horizontal completions about 20 years ago, an entirely new method of logging was developed, fitting sensors integral to the bottomhole assembly of the drill string inself, and also of physically drilling the well using downhole turbines to rotate the bit instead of rotary table/top drive power rotating the entire drill string from surface. The new logging method is called MWD (measurement while drilling) or LWD (logging while drilling). Instead of transmitting the information electrically up the cable, it transmits pulses via the drill mud. Newer still, electromagnetic downhole data transmission systems are available for specialised underbalanced drilling using air, foam or mist instead of mud.
Pharos: +1 for all your posts so far. I can see people wondering what "underbalanced" means. Most wells are drilled underbalanced to some extent. For those who don't know the jargon, there is a risk of blowout with any well, where formation water pressure (pore pressure) in the earth exceeds the downward pressure of the drilling fluid in the well. In the earlier days of drilling, up to the 1970's and 1980's the well fluid would have additives to make it denser (eg KCl), so reducing the risk of blowout. The problem with running too high a density in the drilling fluids is that when you reach a porous formation such as a reservori the drill column fluid pressure (known as the mud weight) forces the drilling fluids ("mud") into the formation, blocking the pores. This means the well may not flow hydrocarbons and the mud invasion affects subsequent wireline logging measurements, possibly obscuring the detection of hydrocarbons. Soviet era wells such as those drilled in places like Yemen were often prone to his problem: I recall one well in the Rhub Al Khali ("Empty Quarter") between Saudi Arabia and Yemen being plugged and abandoned as a dry hole by the Russians. Subsequently Shell took the acreage and planned a 3D seismic survey. On surveying in the old well head to provide a data tie, the surveyor discovered the old well head classified as a dry hole was leaking gas and sitting in a pooll of crude oil in the desert!
I think it is fair to say that log quality from MWD/LWD is pretty poor, but it is more than sufficient for geosteering a well.
BBC South news has had a more expanded bulletin tonight on oil and gas exploration in Dorset and Wytch Farm. Interviews with locals who cannot see any problem with Wytch Farm. Interview with Peter Barton "anti-fracking campaigner", Chair of West and South Dorset Green Party with lots of anti-fossil fuel nonsense and the urgent need to act on climate change. Also Dorset FOTE campaigner who couldn't understand why there is support for Wytch Farm and not for offshore wind.
Could it be that Wytch Farm is benign and invisible and offshore wind is a blot on the beautiful Dorset landscape?
to quote from a Rezillo's hit...Someone's gonna get his head kicked in tonight...."
@ThinkingScientist
"I think it is fair to say that log quality from MWD/LWD is pretty poor, but it is more than sufficient for geosteering a well"
About 24 months ago, I was hired as a consultant for a structural geological analysis of longwall blocks in a large operating Chinese mine. The earlier longwall blocks had been plagued by "unexpected" folds and faults, causing huge operational expense over-runs
In order to degas the seam (CH4) in each mining block prior to the longwall shearer coming through, drill crews had peppered the block to be mined with roughly horizontal holes that had been surveyed using MWD equipment. Each hole had also been "touched" to roof and floor for reliability quite a few times in its' individual traverse
So I had a general map of the earlier blocks (not detailed enough, of course) but also about 30,000 confirmed, levelled points of x,y,z roof and floor across the next block
This data allowed a really good 3D structural model of the next block to be created. This generated map allowed the shearer to be controlled across its' chosen horizon in each pass with a minimum of disruption, as the seam profile (rolls, folds, faults) was now accurately known in advance
The result was a minimum saving of over USD$30m in operating costs for each of the subsequent 25 blocks
So I do not regard the current state-of-art MWD as "pretty poor"
TS
That begs some explanation of the downhole environment in pressure and temperature terms which some may be unfamiliar with. Downhole pressures typically are what is termed normally pressured, related to the pressure generated by a the vertical column of water saturating the rocks. Surface groundwater is termed meteoric (charged from rain/snow precipitation infiltrating and continuously replenishing any shallow aquifers for human water supply or running off via springs into the river catchment systems. Thereby it is freshwater and potable.
Deeper rocks, typically below sea level, do not usually participate in this meteoric regime. They typically contain ancient trapped, so-called connate water dating from depositional pre-history. As the majority of sedimentary rocks were deposited in marine environments, the majority of deep connate water is saline and non-potable. Oil and gas exploration almost invariably takes place deep in the connate water zone. Side note- Saline water may also underlie freshwater in meteoric aquifers near the coast without a physical shale barrier separating them, simply because salt water is heavier. (Exploiting freshwater aquifers for water supply too hard risks drawing in saltwater contamination).
Subsurface pressures increase remorselessly with depth, at a gradient of about 0.45 psi/ft. So a well drilling at 10,000 feet has a bottom hole pressure of around 4500 psi. In a mud filled hole, over or underbalanced, water incursion simply mirrors the pressure gradient so any inflow typically stands in the well equal to ambient atmospheric pressure at surface- however, incursion of free gas ( much lower density) in an uncontrolled underbalanced well risks replacing drillling mud by a gas filled hole with a wellhead pressure near equal to downhole pressure, risking blowout.
Subsurface temperature, like pressures, also increase remorselessly with depth. Every log run always carries two or three thermometers to record the well temperature at log TD. Typically the thermal gradient is about 1.5 degF/100feet or around 25 degC/km. So a 10,000 foot well with an ambient surface temperature of 10 deg F has a bottom hole temperature in the region of 160 deg F. Drilling mud circulating back up to the rig is hot and steamy.
BBC Southeast News were disgracefully trying to stir up 'controversy' about an imminent application to drill from 'Celtique' at Fernhust in the South Downs National Park. They wheeled out a spokesman from 'Frack-Free Sussex' and opposer Lord Cowdrey, bemoaning it and predicting protests similar to Balcombe.
I screwed up my F's and C's for surface temp. Av 10degC =50 degF, For 10,000 feet at 1.5 deg/100ft BHT is 200 degF
Mike Jackson
1) Journalists, policy wonks and their own tame people.
2) Because if they ask the wrong sort of people (e.g. engineers and geos), they're going to get the wrong sort of answers. That's the entire point of enquiries. Don't have one unless they are guaranteed to come up with the right result. IMHO.
Thanks Pharos, +1 again.
This thread is a perfect example of why BH is such a valuable blog.
To a layman like me, Prof Smythe's comments appeared to be expert and knowledgeable although the tone of his remarks and the apparent lack of communication with Cuadrilla made me suspicious.
First of all the blog links to a calm, clear repudiation of those comments. Then a number of true experts add their views on this thread, reinforcing the criticisms and expanding on the subject for the benefit of the majority with some fascinating details of the industry's workings.
Thank you. A masterclass.
Too, true, mikeh. I, too, am a geological and mining ignoramus (though I like to think that I have some understanding, even if it is only based upon school lessons in geography and history, with a bit of help from chemistry and physics). I really only post to remind everyone that I’m still here.
mikeh
Thanks for that, and I'm learning too (10 years redundant). The take-home should be the level of professionalism and sophistication of the oil industry in particular and extraction industries in general. Add in the costs (millions, dollars or pounds) and the need for private industry to make a profit, it should be apparent that snags/downtime/accidents get a lot of attention from the boss man, let alone the elfinsafety and DECC.
What should also be apparent is that Greens(TM) have no conception of professionalism and professional responsibility. I can't peer into "Green" minds (don't want to go there), but I suspect they have a mental picture of Kentucky 1923 with wall-to-wall rigs and wells, and waste oil everywhere. Wytch Farm is the perfect antidote, but Greens won't go there. They are in denial.
"on BBC South news this morning that environmentalists are objecting to Perenco continuing with Wytch Farm. 190 wells over 30 years, they have fracked there for years, nobody in even noticed. No environmental damage."
Presumably they only became aware of Wytch Farm when it was pointed out to them during the current Balcombe fracas.
ianl8888 - I wonder if the sophisticated results obtainable from current MWD/LWD technology have been the cause of the slow take-up of wired drill pipe?
Although this is probably a dead thread by now, I realised after posting my piece about geothermal and geopressure gradients that I neglected to mention the most important aspect of all- their importance in generating all our 'fossil fuel' energy resource. These all originate from the organic debris present in sedimentary deposits- predominantly plant kerogens. Although bacterial decay of organic matter starts the moment the living organism dies, in oxygen poor bottom conditions much material is trapped buried and preserved along with the accumulating sediment before being totally consumed chemically or biologically.
Shales (compacted mudstones) form the most volumetrically abundant sedimentary rocks, and some of these, particularly the Kimmeridgian shale as a Balcombe, fortuitously contain the richest preserved kerogen percentages, including the most oil prone algal kerogens. Coal is a special case- effectively 100% woody kerogen preserved in seams representing drowned delta top swamp forests.
Oil does not start to form in any significant quantity from these kerogens without heat. So substantial geological burial is required to place the potentail oil source rock, via its geothermal gradient history, into the so-called 'oil generation window'. This is typically 150-300 degF. If the source rock is subjected by even greater burial to even higher temperatures, the oil starts to crack to light condensate and ultimately dry methane gas in the 'gas window' typically 300-400 deg F.
The ideal situation for oil and gas entrapment has a geological history of early structural trap formation, burial of source rocks into the fully mature oil window and progressive overburden compaction to assist 'squeezing out' as much oil and gas as possible as primary migration into the porous reservoir units. Then secondary migration in these reservoir carrier bed units under bouyancy, oil and gas being lighter than water, can ensue uphill into the available trapping structures. Much of this of course bypasses traps and leaks eventually finding its way to the surface to contribute to our precious 'environment', quite naturally, of course, in the fullness of time.
kellydown! We'll get monkeyboard, bellnipple, rathole and junkbasket posting soon!