Wednesday, 30 January 2013


Sorry, been a bit lax in terms of regular posting this month. I've been a busy boy. Just quick one for now to keep you interested, which is to mention 'FrackNation', a new film that has come out recently in the US.

The aim of the film is to show the other side of the argument to Josh Fox's Gasland, which was the real start for the anti-fracking movement. Even now, when anti-fracking groups are set up, Gasland is often the first port-of-call for resources about why fracking is bad.

The film has been funded by Kickstarter, which is a crowd-sourced funding project, so it's not paid for directly by oil companies (although it wouldn't surprise me if many of the funders were people who have benefited from shale gas through leases, royalties etc).

The film has been released on US cable, but unfortunately I suspect that, short of buying the DVD, it might be a while before it is available in the UK. So in the meantime, here are a few trailers:

You can see that the film follows a similar 'intentionally-low-budget-looking' format, candid camera style popularised by the likes of Michael Moore.

Subject matter apart (and I look forward to seeing the full version, by all accounts Josh Fox and Gasland appear to have been blown out of the water), I find this style of documentary-making interesting: rushing up to people and asking them awkward questions, and no doubt employing some selective editing. I'm sure that a good journalist, combined with selective editing, could make anyone look pretty bad about pretty much anything. Usually, it's the Josh Fox's and Michael Moore's, who are from the left of the political spectrum, doing this. Now it seems those of the right (and the producer, Phelim McAleer, does appear to be fairly Conservative) are picking up on this tactic.

Anyway, enjoy the trailers, I will try to watch the full version and let you know my thoughts as soon as I can.

Saturday, 5 January 2013

Conventional vs shale: what's the difference?

Oil and gas production is a complicated business. To get those molecules of hydrocarbon from the microscopic sandstone pores kilometers underground all the way to your car's petrol tank or your home's central heating system takes a huge amount of engineering. Shale gas extraction is no different in this respect - in fact it requires additional stages of engineering on top of what is required for normal gas and oil extraction. So I figured it would be of interest to look at what is different in shale gas compared to conventional, and what is the same.

Wells drilled to extract conventional HCs are pretty much identical to shale gas wells. They are drilled in the same way, cemented in the same way. Horizontal wells are now common in conventional production, just like they are in shale gas. Check out the map of the Weyburn oilfield (Canda) below - each line is a horizontal well bore, some of which produce oil, some of which inject CO2 to help force the oil out. Conventional and shale wells have pretty similar risks in terms of wellbore integrity and gas leakage.

(click to enlarge)

Hydraulic Fracturing
This is one of the big differences between conventional and shale gas. Although HF is often used in conventional gas fields, it is not usually on the same scale as for shale gas. So, what extra risks does the HF process itself entail? Evidence is pretty clear that the fractures that are created are not providing contamination pathways for gas or nasties to get back to the surface: the fractures created are simply too small and too deep - not even the most ardent anti-frackers are arguing this I don't think. Of course, hydraulic fracturing uses water, some of which comes back up to the surface - I'll talk about this a little more below.

Number of wells
Usually, you would expect to have fewer wells in a conventional field than for a shale gas field. This isn't always the case - look at the number of wells at Weyburn, above, or the Jonah gasfield (below). However, as a general rule, expect more wells for a shale field.

Water Usage
Firstly, water usage. Some water is required to drill a well. I'm not sure how much, but it rarely seems to be an issue for conventional wells. On top of that, hydraulic fracturing also requires 1-5 million gallons (about 10,000-20,000m3, or 4-8 Olympic swimming pools) of water. 5 million gallons sounds like a lot, but it's all about the context. In the UK, 2,559 megaliters of water are lost through leaks in our water system every day. That's 676 million gallons (or 2.5 million m3, or 1000 Olympic swimming pools), enough to frack more than hundred wells every day! If we improve leakage rates in our water system by 1%, we'd have enough water to spare to frack a well every day. So water usage isn't really an issue - if you're worried about the next hosepipe ban, get on to your water supplier to fix their leaks.

Produced water
One of the issues with fracking is that the injected water comes back up the well. Even if the latest CleanSTIM fluids are used (using only ingredients available for use in the food industry), the returning fluids are contaminated by their time in the reservoir, picking up NORM, heavy metals and organic compounds. When the water is returned up the well, it has to be dealt with.

But what about conventional HC production? Most conventional reservoirs have what is called residual water saturation - the part of the rock's pore space that is filled with water rather than hydrocarbon. When the reservoir is produced, the water comes up along with the oil and gas. This water has been in contact with the oil, gas and rock for millions of years, so like the fracking water it may be contaminated with NORM, heavy metals and organic compounds, and it must be dealt with. It's not actually an issue I'd given much thought to until now - having a blog is sometimes great for making you research something you otherwise hadn't considered. As far as I can gather from this page, it appears that in the North Sea this produced water is treated on site and then dumped into the sea. This was quite surprising to me - that it was easy enough to clean the water on-rig to a standard where it can be put back into the sea! Onshore (at Humbly Grove for example) it would appear that this water is re-injected into a deep lying aquifer (I couldn't find out anything about whether it was treated first or not).

So dealing with produced water would appear to be as much an issue for conventional production as it is for shale gas. The main difference is that for shale gas all the water is produced immediately in the days after the frack, while for a conventional field it is produced continuously through the life of the field.

Shale gas extraction has generated a couple of small earthquakes near Blackpool. However, induced seismicity occurs in conventional reservoirs too (read the abstract of this scientific paper, or the whole thing if you have access). So again, as much an issue for conventional production as for shale gas.

Surface Impact
I'm sure many of you enjoyed the good debate between myself, 'John' and 'Anonymous' on my previous post about the surface impact of shale gas extraction. In as much as shale gas fields will probably have more wells than conventional fields, there will be a bigger surface impact. Conversely, however, shale gas wells will be capped with Christmas trees, which are fairly low impact in comparison with a nodding donkey which might be needed for a conventional oilfield. Examples of both are below.
Oilfield nodding donkeys (above) and gas production 'Christmas Tree' (below):
As for other 'excrescences' of the oil and gas processing chain, as John so eloquently described them - pipelines, compressor stations, processing facilities - these are pretty much the same whether it's shale or conventional gas (obviously, oil requires different processing facilities).

All of this leads me to a question that I'd like to ask those who are opposed to shale gas development. Would your opposition be as fervent if new conventional gas fields had been found under Blackpool, rather than shale gas?

Shale gas, and fracking, sounds scary in comparison with the conventional production that we've had for a hundred years. However, when you break things down and look at the major objections to shale gas, are they much different to conventional operations? Wellbore integrity (and the risk of gas leakage from wells) is as much an issue for conventional gas as it is for shale. Dealing with contaminated produced water is always an issue for conventional reservoirs, much as it will be for shale. Induced seismicity happens for both conventional and shale. Shale gas will likely have more wells, and so a greater surface impact, than conventional gas, but this is an incremental increase, not a game changer, while much of the related infrastructure - pipelines, processing facilities etc - will be similar. Intellectual honesty would dictate that if you are opposed to shale gas extraction for these reasons, you should be equally opposed to conventional onshore gas extraction.

Given this, would a better description for those opposed to shale gas development in the UK be 'anti-onshore gas development', rather than 'anti-fracking' or 'anti-shale-gas'?

Thursday, 3 January 2013

Book Review: A Hole at the Bottom of the Sea

Among the socks, port and cheese, I received a rather good Christmas present this year: A Hole at the Bottom of the Sea (The Race to Kill the BP Oil Gusher), by Joel Achenbach.

It tells the story firstly of events on the Deepwater Horizon rig in the days leading up to the catastrophic blowout, and then of the efforts by BP and the US government to cap the well as it gushed approximately 50,000 barrels of oil every day.

First and foremost, it gives an insight into the complicated engineering procedures on a rig - essentially incomprehensible to the average man on the street. For example:
This story had its own interesting lexicon, a language crafted by men who use tools. Offshore drilling is rough stuff, hard-edged, coarse [...] What they do is complex, difficult and dangerous. They drill holes in the pressurized Earth. They extract crude. They pump mud and cement, and handle gear weighing tens of thousands of pounds on a rig that weighs millions [...] And so even the language is masculine, the words often short, blunt, monosyllabic. Spud. Hot stab. Top kill. Junk shot. Dump box. Choke line. Kill line. Ram. Ram block. Ram packer. Side packer. Stack. Valve. Tick. Pod. Borehole. Bottom hole. Dry hole. Drill pipe. Coning. Cylinder gauge. Cavity. Rat head. Stopcocking. Torque tube.... 
More importantly, it shows how industrial accidents can occur. In complex systems, events can have unintended, unforeseen consequences that can turn small mishaps into massive disasters:
The Macondo well blowout was a classic industrial accident, a sequence of tightly coupled events in which no single action could have caused the disaster. Some of the mistakes are screamingly obvious in retrospect, but at the critical moments, decisions were fogged by uncertainty.
This has wider implications than a single accident in the Gulf of Mexico:
The Deepwater Horizon tragedy is a reminder of how little most of us know about modern technology. We don't know how anything works [...] The irony is that we're inhabitants of a planet that is becoming increasingly engineered. The engineers are brilliant and creative, and most of us have little appreciation for what they do, so deftly is their handiwork woven into our daily lives.
Our engineered planet poses a challenge for us:
We need to remember that sometimes bad things happen to complex systems, that gremlins roam the earth. Things go wrong. Count on it. The engineered planet challenges all of us to be a little bit smarter, to pay more attention. We need to learn the jargon, understand the risks [...] Even if there's not another deepwater blowout anytime soon, there will be something that happens, something awful and unexpected, that involves the failure of a complex technology. It could happen in outer space, at the bottom of the sea, in a nuclear power plant, on the electrical grid, or somewhere in the computer infrastructure that networks the planet [...] There will be more black plumes. There will be other fires on the horizon. Low-probability, high consequence events are made all the more devastating, potentially, by the scale and sophistication of modern technology [...] As we go down this technological path, we will count on complex systems to work correctly. We will assume that someone smart is in charge, looking over our world, protecting us [...] Here's the thing: Usually the technological magic works. Usually nothing terrible happens. Usually.
This is not a Luddite call. New technology is vital to human progress. Any call to return to some sort of agrarian free-living paradise is to forget how cruel and unpleasant life in these societies used to be. Nevertheless, we have to treat our novel systems with the respect they deserve:
As we grope our way forward, we can develop a few rules. Such as: When doing something risky, remember that risk build like plaque, Make sure your backup plan really is in back and won't get blown up out front along with your plan A. Remember that low probability, high consequence events become more likely given enough time and opportunity [...] Measure your misery. Don't shy away from knowing precisely how bad you're screwed [...] Keep the fixers away from the talkers. Don't expose the engineers to any political shenanigans, media madness or public outrage [...] And finally, the most important lesson: Keep your wits about you. It is extraordinarily unlikely that the disaster you are dealing with is qualitatively worse than the many calamities that human beings have survived to this point. In fact, it's probably not as difficult as any number of challenges that people have overcome, from wars to famines to pestilence to floods to storms to earthquakes. People survive, rebuild, thrive. The strange thing about Armageddon is that it never actually happens. So don't panic. The problem will be solved. May not be pretty, but it'll get done.
I think Achenbach's take on this can be readily applied to shale gas extraction: a complex engineered system, where usually the technological magic usually works just fine, but there is always the possibility of a Black Swan event. It is the duty of engineers to properly respect the system they have constructed, keeping their wits about them to do their utmost to minimise risks, to prevent risks building up like plaque. It is the responsibility of the public to learn the jargon and understand the processes, while at the same time not turning engineering issues into political shenanigans, media madness and public outrage. This doesn't lead to sensible decision making.

Anyway, I thought it was a great read. My better half was very disappointed as I was lost to her, deep in the pages of the book, through much of Christmas Day evening and Boxing Day. I'd recommend it not just to people interested in learning more detail about the BP disaster, but to learn much more about how we drill for oil out at sea most of the rest of the time when things aren't going wrong, and to gain an appreciation of the scale of complex engineering that is required simply to put petrol in your car. Read it, and then remember it next time you fill up.

Finally, one point worth remembering, from all the nerds out there:
In crunch time, call in the nerds as well as the cowboys.