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Shane

Joined: 31 Oct 2005
Posts: 3467
Location: Doha. Is hot.

Posted: Tue May 31, 16 5:09 am Post subject:

All facilities leak a little - it's what's known as fugitive emissions. You can see the default factors for emissions calculations in Section 9.5 of this report. These are taken from statistics of operating plants, so are pretty representative. I've only ever dealt with offshore fugitive emissions calculations, so it's quite an eye-opener to see how much higher the emissions are for onshore plant.

The often-used snippet about methane being 20 times more effective as a greenhouse gas is never quoted to the full. Yes, it has roughly 20 times the greenhouse gas effect, but carbon dioxide lasts roughly 20 times longer in the atmosphere, so total lifecycle effect is very similar for both compounds. The industry made a wholesale move from unlit to lit flaring (i.e. converted large methane emissions to large carbon dioxide emissions) some time back, which would have very quickly made a difference to the potential for shorter-term global warming - now the challenge is to massively reduce the carbon dioxide emissions in an increasingly-populated world that shows no signs of reducing its hunger for energy consumption.

Mistress Rose

Joined: 21 Jul 2011
Posts: 15967

Posted: Tue May 31, 16 6:42 am Post subject:

I can see that you would be surprised at the difference Shane. They are very much higher on shore.

We are close enough to Fawley oil terminal to see the flares from some places locally, and over the years we have seen a significant reduction in the number of flares. We always assumed it was because they were handling and using the oil more efficiently. I am talking since it became a big centre; probably 50 odd years.

dpack

Joined: 02 Jul 2005
Posts: 46211
Location: yes

Posted: Tue May 31, 16 9:20 am Post subject:

umm interesting ,perhaps we should be more concerned about the voc's from both the production and end user emissions.

i think the stuff below makes sense but i might have missed some vital data or misunderstood some of the implications.

meth and eth are maybe not the greatest issue if their overall effect is similar per mole to co2 but voc's have a vary unpleasantly complex soupy photochemistry in the atmosphere and although globally natural sources are several times greater than the fossil ones the fossil ones are concentrated at low level (well to start with) in areas of high human habitation and i assume around production and transport facilities.

im sure end user (part combustion and especially displacement of voc saturated air when filling the fuel tank etc etc )load is higher than the production load(avoiding bangs etc etc ) but photochemical smog has a more immediate effect than climate change.

this thought still puts extreme energy fossil (as proposed for the uk) in the dock but for a more pressing reason in that onshore leaks will bump up the voc levels at a local scale which has a direct effect on the locals.
gas extraction from shales is probably less of a problem than from coal (cbm/ucg) but iirc shales do contain more organics than eth/meth which will need removing from the gas stream which has the potential for vented or lost voc's.

Shane

Joined: 31 Oct 2005
Posts: 3467
Location: Doha. Is hot.

Posted: Tue May 31, 16 11:58 am Post subject:

Mistress Rose wrote:

We are close enough to Fawley oil terminal to see the flares from some places locally, and over the years we have seen a significant reduction in the number of flares. We always assumed it was because they were handling and using the oil more efficiently. I am talking since it became a big centre; probably 50 odd years.

It used to be standard practice to flare all the gas from the low pressure separators, which are the vessels that are used to remove the very last of the gas entrained in the oil before it is routed to atmospheric storage, but it's now standard practice to recompress that gas and route it back into the process. Not only does this significantly reduce the amount of flaring, but the flare burns a lot cleaner as the recaptured components have a fairly high molecular weight a produce a very sooty flame.

Loading terminals also used to flare all the gas that was displaced from tanks as they were filled - nowadays it's becoming the norm that the gas is captured and routed to the corresponding tank that's emptying.

I suspect a combination of the above is why you've seen Fawley's flares reduce considerably over the past few years - I doubt there's anywhere left in the UK now that still flares their LP flash gas.

Mistress Rose

Joined: 21 Jul 2011
Posts: 15967

Posted: Wed Jun 01, 16 7:34 am Post subject:
Thanks Shane, I did wonder what the reason was. There is one flare occasionally now, but no idea what that is from. Dpack, the amount of gas that comes off when a petrol tank is filled is not huge, but I suppose if that is multiplied by lots of cars. My main worry is the organic content of it being carcenogenic, do not a good place to be all the time.

dpack

Joined: 02 Jul 2005
Posts: 46211
Location: yes

Posted: Wed Jun 01, 16 8:59 am Post subject:

for every liter of fuel put in the car(or whatever) there is a litre of voc saturated air displaced.

those voc's react in the air with o2,no2,so2,so3,o3,h2o,halogens, assorted organic compounds already created by the fuel vocs and compounds from other sources etc etc .with sunlight often providing the activation energy for the simple chemistry of each reaction a variety of moderately complex compound are formed and these also interact in a variety of ways. this soup also reacts with micro particulates and combustion products from burnt and partially burnt fuel.

the whole cocktail is called photochemical smog and has ground level and stratosphere effects both physical and biological in nature.
the biological effects are measurable on health by direct and epidemiological means ,the climatic physical effects are more complex but include greenhousing,albedo alteration in both directions,cloud seeding etc etc .

iirc the overall climatic effect is a slight cooling trend but although that might seem like a good ides the chemical cocktail contains many truly nasty components.

adding extra voc's to the existing cocktail from the planned complex infrastructure of extreme oil and gas production would be best avoided but in a worst case scenario(of multiple wells and pipes and process facilities onshore in the uk) it must be minimised so aiming for the 0.1% leakage emissions rather than the 2 and a bit should be a factor in plant design and operation.

dpack

Joined: 02 Jul 2005
Posts: 46211
Location: yes

Posted: Wed Jun 15, 16 12:59 pm Post subject:
we have considered what will happen to the backflow waste water but it seems there are some issues with the fracking companies plans waste water linky

dpack

Joined: 02 Jul 2005
Posts: 46211
Location: yes

Posted: Thu Dec 22, 16 1:33 am Post subject:

as some will have noticed the ryedale test pad has got a legal ruling for work to start on test fracking,

that isnt my point here

during an exchange of view in the guardian cif a couple of folk were very pro , one was outed as paid then i checked out the other and found this quote from them about a year ago in a different discussion on the same type of theme. their commenting is almost entirely pro fossil/pro fracking and often about the licences for the bowland shales.

"I did. I'm paid to post here by Exxon."

two points whatever it says on the licence it is highly probable it is exxon behind it and paid shills should be more discrete

the first point is interesting as it is the first time i have come across any hint of which of the seven sisters is behind the bowland shale project, the front companies who own the licences all seem small, low asset and potentially expendable.

follow the money is often a good tactic. ha ha ha .

Mistress Rose

Joined: 21 Jul 2011
Posts: 15967

Posted: Thu Dec 22, 16 7:09 am Post subject:

We have a number of 'conventional' oil wells near here which use nodding donkeys to do the extracting. Another company wants to start a different sort of well with horizontal drilling and 'acid fracking'. There is a great deal of concern as this is under the aquifer that supplies the whole of the area, and being all on chalk, the acid is going to dissolve the chalk and make the opening of fissures more likely. Any comments from Shane or anyone who knows more about this technique?

dpack

Joined: 02 Jul 2005
Posts: 46211
Location: yes

Posted: Thu Dec 22, 16 10:17 am Post subject:

most of the info you need is in the 23 pages of this thread, it is unlikely that the fracking would affect the aquifer directly but the in use extraction and legacy issues might. it depends partly on how unlucky/careless they are regarding well containment and partly on the geology, if there is no impermeable/ unfaulted layer between the fossil bearing strata and the chalk it would be very iffy.
there is also the issue of waste water protocols, which range from you wouldn't want to drink it through no paddling to it destroys an aqueous ecosystem.

the risks are quite low per hole but overall risks can be quite high if they drill enough holes.

ps any extra fossil carbon /hydrocarbons released to atmosphere is not going to reduce the damage from AGCC

Ty Gwyn

Joined: 22 Sep 2010
Posts: 4613
Location: Lampeter

Posted: Fri Dec 23, 16 9:33 am Post subject:
Chris, They have already drilled horizontally on some of them oil well`s,i forget the distance,but some are out under the channel, Acid for fracking,not heard of that as a component before,that is worrying if true. Theo, I would be more worried if the area was faulted.

dpack

Joined: 02 Jul 2005
Posts: 46211
Location: yes

Posted: Fri Dec 23, 16 11:43 am Post subject:

fracking fluid is mostly water with a bit of detergent and a tiny bit of quite a few things that improve flow and holding the sand component in suspension while pumping.afaik the process is mechanical rather than chemical so any additives are to improve the rheology.
however it does release the gasses,oils, minerals etc and some of these are returned to the surface with the fracking fluid and as the target products of the process.

as ty says faulting is a major issue which can provide the route between the hydrocarbon bearing strata and the aquifer or surface. the geological mapping of the system should indicate major faulting but isn't a perfect science (think tapping a vase to check for cracks or tiny voids in the clay)

self pumping(ie pressurised) fields are sealed or the stuff would have escaped already, low power pumping such as for oil using donkeys tend to slurp stuff into the hydrocarbon strata as the product is extracted ( this can cause problems while in use or in legacy) but high pressure systems such as fracking shale or using high pressure water to displace oil can shove hydrocarbons out of their strata into other geology as well as up the pipe as intended.

if one is objecting there are two issues that the seven sisters have no valid response to :

1 . burning fossil hydrocarbons releases co2 adding to AGCC forcing over centuries (see stuffed by an ice age for plenty of very strong evidence )

2. a perfect system leaks when working properly, even the best extraction, transport and use systems have a small (industry figures vary but 1.5 % in production, 2% upwards in transport and a variable amount at the use end of the system ) but significant loss of unburned hydrocarbons, methane is 20 times more effective as an AGCC forcing but about 20 times as fast to "decay" from the environment as co2 so it has a similar overall effect but delivers it in a decade rather than a couple of centuries. one could describe that rate of effect as the difference between a candle and a stick of dynamite and a fair figure for overall loss might be 2.5% of total production (it can be far higher if things go wrong).

the new york state report is full of good evidence for not allowing such extraction methods if you don�t want the environmental / public health issues.

regarding under sea extraction if a company uses it as an example of "nothing went wrong when we did that" there are a few significant differences

it is hard to see problems
nobody uses a marine aquifer for a water supply
oil extraction is very different from shale gas extraction
every production pad works a different local geology (see faulting)

frack-off are a bit simplistic at times but they do have a moderately good data base and contacts system

Mistress Rose

Joined: 21 Jul 2011
Posts: 15967

Posted: Fri Dec 23, 16 2:36 pm Post subject:
There are enough people objecting without me adding to it including our water supply company and I think the EA, as well as a lot of locals. I am interested on the grounds that I like to learn the facts (if they are known) or the probability of a problem and if it seemed pretty sure to cause a problem I would then add my voice.

dpack

Joined: 02 Jul 2005
Posts: 46211
Location: yes

Posted: Fri Dec 23, 16 5:31 pm Post subject:

Mistress Rose wrote:

There are enough people objecting without me adding to it including our water supply company and I think the EA, as well as a lot of locals. I am interested on the grounds that I like to learn the facts (if they are known) or the probability of a problem and if it seemed pretty sure to cause a problem I would then add my voice.

as to facts rather than hyperbole from either side a lot can be found in the chat and links in this thread.
even the exxon shill was rather in awe of the facts I was chucking at them ( and said so ) in response to their "facts" and very selective facts..

Ty Gwyn

Joined: 22 Sep 2010
Posts: 4613
Location: Lampeter

Posted: Fri Dec 23, 16 9:29 pm Post subject:
Chris,Maybe your local library might be a good port of call,most libraries stock BGS maps,they will show the geology in your area plus all known faults and folds down to a great depth.

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