Effect of fracking on railway lines and traffic

[whole diary]

[grahame]

From the Frome Standard



What views to members have / knowledge off the effect of fracking on railway infrastructure, other businesses that make use of rail (such as the mendip quarries), on ancient buildings such as Longleat House (and Frome Station!) and on passenger and freight traffic to and from the area?

[grahame]

Just received in my email ... quite a widely circulated note, referring to a council meeting at which public would have been admitted, so I think I can quote ...

Subject: Fracking in Trowbridge
 
Have you guys seen the detailed document about fracking sites for fast tracking?
 
There is one allocated site in there ^ application site ST85 ^ that covers an area going from Westwood and Hilperton in the north down to Westbury in the south.
 
It runs all over Trowbridge.

We need to get an official view from County Hall ^ especially as Toby Sturgis told us that we should not worry our little heads about it ^ when Chris Caswill asked him a question about fracking at Full Council a few months back.
 
As I understand it consultation on the whole exercise finishes in the middle of September 2015.

[Western Enterprise]

Mining usually produces a problem with the railways, subsidence is quite well known in mining areas and is shown up with telephoto lenses and the like.
Its not surprising when you are taking the best part of 1-3 meters of coal from beneath your feet, even if there are supports.
With fracking, I'm not sure much material is removed from the base rock so there is not much to move.
There may be some heave as fluids are injected, but that also will not be much.
W.E

[Oxonhutch]

Grahame, I think people need to understand what ^fracking^ is. The word is an unhelpful American oilfield term (think cowboy hat, plate-sized belt buckles and swagger) for hydraulic fracturing. It has been used in the oil and gas industry since the 1940s and in the North Sea since the 1970s. Oil and gas is trapped in the pore spaces that exist between the grains of sand in the sandstone reservoir. This pore space ^ called porosity ^ normally constitutes between 15-20% of the total rock volume and is normally filled with water. Very salty water at normal reservoir depths of, say, 2000 to 3000 metres (in old money:  6500 ^ 10,000 feet; 1^ 2miles down). In a conventional oil field reservoir, the pore spaces interconnect and fluids (water, oil, gas) can flow from one pore to the next and so on through the layer of rock ^ this is called permeability. Oil and gas being lighter than water flow up hill and collect in and dome-like structures underground. Petroleum geologists look for these dome like structures and drill into them to tap their potential reserves of oil and gas which will flow naturally into the drill hole because of the natural permeability of the rock.

However, some rock deep underground is composed of finer grained particles has a much lower porosity and hardly any permeability. Also, this type of rock tends to be rich in organic matter which produces oil and gas given the right temperature underground (between 90 and 120^C if you are interested). There is lots of this kind of rock beneath us and it contains lots of oil (and gas). It just cannot get out because of the very low permeability.  This is where hydraulic fracturing comes in.

A hole is drilled into the oil bearing, fine grained rock ^ known as a shale ^ the hole curving at the right depth to become horizontal, drilling down the plane of the shale.  This is usually 2000 to 3000 metres vertically down, and up to an additional 2000 metres horizontal.  This depth is way below the water table from which we draw our drinking supplies (down to about 200 metres) and there is over a mile of tight rock between the two. The vertical section of the drill hole is lined with multiple layers of steel (called casing) and cement so that it does not leak. The horizontal section is open to the shale.

In this horizontal section, at multiple stages in the bore, very high pressure water and sand is pumped into the shale to crack it open. The water and sand is forced into the cracks. The pressure is then released and the water leaves the cracks but the sand stays in there and keeps the cracks propped open (the sand is called proppant for that reason). These cracks, now propped open by the sand allow the oil and gas that was trapped in the shale to flow into the drill hole and be recovered to surface.  These cracks extend up to about 50 metres into the shale ^ up, down and sideways so there is still over a mile of tight rock between the ends of the fractures and the water table ^ let alone the ground surface.

Much media attention is placed on the additive chemicals in the water sand mix. The idea behind these is to increase the effectiveness of the process either by making the water a little more viscous ^ so as to carry more sand ^ food grade guar gum is a favourite, inhibit the swelling of clays ^ by controlling the salinity, breaking down carbonate cements with weak acids ^ think vinegar rather than stomach acids, and disinfectants to make sure no surface bugs, bacteria and/or algae are introduced into the pristine reservoir rocks ^ these life forms eat oil and produce undesirable by-products, so you want to keep the environment totally sterile. Compared to the quantities of water and sand, these additives are very small ^ not least because they are very expensive.

So the net effect on surface ^ none at all. The fracturing occurs over a mile; possibly two, underground and the fractures do not propagate far from the well bore relative to the depth.  The fracturing does cause very small earth tremors, usually about a thousandth of what is detectable by humans.  The industry listens for, and monitors these, because it tells the driller how effective the process is and how far the fractures have propagated.

Around Blackpool two larger earth tremors (2.3 and 1.5 M) were induced in nearby faults that were under natural stress.  Many of such events occur in the UK^▸ (United Kingdom) naturally every year and they were significantly smaller than seismic events associated with the coal mining industry that Lancashire hosted in my childhood.

Where the surface disturbance does occur is during the drilling process when a hectare or two is taken for the machinery and ancillary services, and during the hydraulic fracturing process when a large amount of machinery, pipes, pumps and water tanks are required ^ but that is transitory, arriving and departing within days.  When you pay a million dollars a day for something, you don^t want it hanging around for too long.  The fracturing process involves a lot of vehicle and truck movements because there is a lot of material to move on and off site.  It is this aspect of the process that is the most disturbing to the neighbours, but it is relatively short lived.  In production, the wells are benign, silent and almost invisible.

I hope you have found this useful.

[hoover50]

I hope you have found this useful.

Yes, it all sounds OK as long as nothing goes wrong and/or unexpected problems don't occur.

However, just like railways, things do go wrong despite best efforts to avoid them:
http://frack-off.org.uk/mounting-evidence-the-harm-caused-by-fracking

Fracking is just not worth the risk, IMHO^▸ (in my humble opinion).

[Red Squirrel]

Fracking is just not worth the risk, IMHO^▸ (in my humble opinion).

So what do we do? Keep buying gas from that nice Mr Putin? Make more friends in West Asia? Or maybe just turn off the heating?

Oh, or, I know, reopen some of those nice environment-friendly coal mines... 

[JayMac]

Handful of new nuclear power stations should see us right. In addition to the shale gas. Bit of wind too.

[Red Squirrel]

Bit of wind too.

Parrrrp! 

[ellendune]

I hope you have found this useful.

Yes, it all sounds OK as long as nothing goes wrong and/or unexpected problems don't occur.

However, just like railways, things do go wrong despite best efforts to avoid them:
http://frack-off.org.uk/mounting-evidence-the-harm-caused-by-fracking

Fracking is just not worth the risk, IMHO^▸ (in my humble opinion).

I am against fracking to the extent that we should not be using fossil fuels more than we absolutely have to and fracking does seem to be being put forward as a reason not to exploit alternative more sustainable forms of energy, that will not stoke global warming any further.

However, I think much of the material produced by frack off is just scaremongering brought on by nimbyism.  Of course people are strting to believe it 1) because the oil industry does not have a very good record worldwide and 2) because frack-off keep repeating their scaremongering stories over and over again - who was it who said "a lie told often enough becomes the truth".

We have a strong environmental regulatory system in place in the UK^▸ (United Kingdom) (which makes life difficult for the frackers I admit) and I do not believe that there is any risk of water pollution from this type of activity. As oxenhutch said the disruption due to traffic is for a short time only.  One issue that will need to be resolved is the amount of clean water that is required during the fracking, but that is resolvable.

 

[Rhydgaled]

I am against fracking to the extent that we should not be using fossil fuels more than we absolutely have to

Same here. As for the other risks stated with fracking, I have not paid sufficient attention to form an opinion.

Fracking is just not worth the risk, IMHO^▸ (in my humble opinion).

So what do we do?

I think a good start might be to use some of the money saved from reduced wind-power subsidies to get the trial tidal stream turbine off the dockside in Pembroke Dock and into the sea. I'm in favor of wind farms too, to a certain extent, but not the associated pylons. Oh, and explore the alternative designs of nuclear reactor, some of which supposedly cannot meltdown and produce less-dangerous waste.

[devon_metro]

I hope you have found this useful.

Fracking is just not worth the risk, IMHO^▸ (in my humble opinion).

Presumably therefore conventional oil & gas extraction should stop immediately then!?

They both pose risks, however the technology is designed to prevent any damage. Oxonhutch provides a very detailed explanation of the "fracking" process. Many 'conventional' oil reservoirs are hydraulically stimulated to extract the oil. Heaven forbid, they also re-inject gas into the reservoir!