Natural Gas Explosion in Bedford

Slug

Slug

Member
Last Saturday (19th October) a house exploded, killing 1, and seriously injuring another. Yes, it was caused by gas but not the domestic supply. In July, whilst sinking a borehole for a heat pump, at 100 metres a pocket of naturally occurring gas was hit. The borehole was capped, and the authorities were "monitoring the situation".

What would cause natural gas - I am assuming it's Methane - to be created ?. The geology of Bedfordshire is sand, gravel, chalk and clay. In this part of town, its clay, and Bedfordshire clay has a high sulphur content, its why the brickworks were ultimately closed down, might this have any bearing on the formation of this gas pocket ?.....over to you.

www.bedfordindependent.co.uk

Cleat Hill homes still out of bounds after explosion - Bedford Independent

Bedford Borough Council has said it will no longer be able to allow visits to homes evacuated after an explosion in Cleat Hill at the...
www.bedfordindependent.co.uk www.bedfordindependent.co.uk
 
Slug said:
Last Saturday (19th October) a house exploded, killing 1, and seriously injuring another. Yes, it was caused by gas but not the domestic supply. In July, whilst sinking a borehole for a heat pump, at 100 metres a pocket of naturally occurring gas was hit. The borehole was capped, and the authorities were "monitoring the situation".

What would cause natural gas - I am assuming it's Methane - to be created ?. The geology of Bedfordshire is sand, gravel, chalk and clay. In this part of town, its clay, and Bedfordshire clay has a high sulphur content, its why the brickworks were ultimately closed down, might this have any bearing on the formation of this gas pocket ?.....over to you.

www.bedfordindependent.co.uk

Cleat Hill homes still out of bounds after explosion - Bedford Independent

Bedford Borough Council has said it will no longer be able to allow visits to homes evacuated after an explosion in Cleat Hill at the...
www.bedfordindependent.co.uk www.bedfordindependent.co.uk
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Some natural gas can come from some shale/gravel like substrates through decomposition,
Screenshot_2024-10-24-11-28-28-84_40deb401b9ffe8e1df2f1cc5ba480b12.jpg
 
I have no idea where the gas is coming from, but have a lot of questions about how this was handled, as it is in effect a gas well blowout. What planning and engineering went into drilling such a deep borehole? How was the well constructed? I assume no wellhead or BOP as the well was not shut in. Why was the gas allowed to vent and not flared? Why has it taken so long to work out a plan to kill the well? Were people evacuated as soon as the blowout happened, and were they allowed back to visit their homes?
 
Decomposition of organic matter (possibly mediated by bacteria) in anaerobic conditions (lacking oxygen) will ultimately lead to methane gas.
 
Ouan said:
I have no idea where the gas is coming from, but have a lot of questions about how this was handled, as it is in effect a gas well blowout. What planning and engineering went into drilling such a deep borehole? How was the well constructed? I assume no wellhead or BOP as the well was not shut in. Why was the gas allowed to vent and not flared? Why has it taken so long to work out a plan to kill the well? Were people evacuated as soon as the blowout happened, and were they allowed back to visit their homes?
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The initial incident happened in July whilst the borehole was being drilled, homes were evacuated, for a bit, and the hole was reported as being "made safe and with authorities monitoring the situation". Now, admittedly I only have the local on line press to go on, who are actually quite good at not over sensationising, and they get most of their information from the police, who aren't, and local residents.
As for your more in depth questions I presume that now the HSE are involved they will be answered....probably after the inevitable "Witch Hunt".
Though I do fear that there may well be other gas pockets that are effectively capped by the clay soil above....and may be a factor when/if the Bedford leg of the Oxford-Cambridge rail line is built....less than a mile from the explosion.
 
RobinGriffiths said:
Brick clay often has a lot of organic content. Oxford Clay in particular. They save on firing costs because the organics make it self-firing to some extent.
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Correct Robin, Bedford brickworks finally shut not because the clay pits were exhausted, but because the high Sulphur content which was causing acid rain as far as Sweden. A friend who worked there explained that once the kilns were up to temperature the green bricks would outgas so much that they effectively cooked themselves, and that the fire would actually move to different zones during firing.
 
Slug said:
Correct Robin, Bedford brickworks finally shut not because the clay pits were exhausted, but because the high Sulphur content which was causing acid rain as far as Sweden. A friend who worked there explained that once the kilns were up to temperature the green bricks would outgas so much that they effectively cooked themselves, and that the fire would actually move to different zones during firing.
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I was fortunate enough as a small boy to have a tour of the kilns and the clay pits otherwise known as “nut holes“ at the old Marston Valley works just outside Bedford as my father worked there many years ago.
just to expand on Slugs post in case anyone’s interested.
The kilns ran on a seven day cycle and had interconnecting vents which were sealed with newspaper of all things between firing.
The cold kiln was stacked or set with “green“ or raw clay bricks and the entrance bricked up when full.
The fire moved in a circle around the kilns and as the heat built in the kilns adjacent to the raw bricks it passed through the vents and as temperature increased the organic content of the clay ignited firing the bricks until the natural fuel expired and the heat passed on to the next kiln igniting the contents continuing the cycle.
There were thermocouples on the roof of the kilns and a skilled operator would monitor the temperature and feed the fire with a small scoop of coal dust dropped through vents in the top of the kilns if the temperature dropped.
I can’t remember for sure but I think it took 24 hours for the firing at around 1000 degrees C and then several days for the kiln to cool enough for it to be opened and emptied before filling again.
A constant temperature was required as too much variation would result in discolouration or brittle bricks which were no good.
Interestingly any bricks with chipped corners or edges would be put in a giant tumbler which knocked off the sharp edges and corners so the bricks looked like old ones which could be used in renovating older buildings and we’re sold for more money than the perfects.
 
When the clay pots were worked out, I think they were used as landfill and the resulting methane was used to fire the kilns as a way of abating the acid rain in Scandinavia and giving the kilns a longer life.
 
wormster said:
When the clay pots were worked out, I think they were used as landfill and the resulting methane was used to fire the kilns as a way of abating the acid rain in Scandinavia and giving the kilns a longer life.
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Sort of, most of the gas went to a power generation plant, and still does. Those remaining nut holes not full of London's rubbish are either lakes, or the soon to be Universal Studios theme park.

Latest updates have a 100 m safety cordon centred on the borehole, which is described as being open to the elements. The BGS are also now involved in the investigation/witch hunt, so watch this space.

www.bedfordindependent.co.uk

Public safety "a priority" as 100m Cleat Hill cordon remains in place - Bedford Independent

Residents were told that a 100m cordon will remain in place at Cleat Hill as the emergency services and Health & Safety Executive (HSE)...
www.bedfordindependent.co.uk www.bedfordindependent.co.uk
 
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