Heat pump causes gas explosion

Yes. My bad. It seems they built a house on a trash heap.

I have never actually smelt any natural metahne that was odorless. Let me rephrase that.. All gas in ponds and so on smells.

It probably smells of H2S.

My neighbour has drilled several boreholes for her GSHP. That was a couple of years ago, so hopefully we're in the clear.

H2S doesn't smell until it's well beyond lethal. It was one of the things we were always warned about when working on oil ands gas fields. If you see a body lying in a hole somewhere **don't** jump in and pull them out because it's likely full of H2S and you will become a second body in the hole.

Theo

The smell effect of H2S is concentration-sensitive.

And that's the kind of thing that happens to humans near sour gas wells, who don't hear the alarm.

The article also explains it has toxicity properties similar to carbon monoxide.

Paul

Paul

No. Mercaptan.

In a pond?

An ancient forest, perhaps.

Wrong way round.

H2S stinks to high heaven in low concentrations. In high concentrations it kills off your olfactory cells rendering it odourless.

From wiki. “Although very pungent at first (it smells like rotten eggs[54]), it quickly deadens the sense of smell, creating temporary anosmia,[55] so victims may be unaware of its presence until it is too late. “

Tim

TNP is on an utter bollocks roll…

Tim

I think they realized immediately, they had hit a gas pocket. It would be blowing material out of the hole at you, as you were attempting to screw more pieces of drill pipe onto the rig.

Somebody attempted to pour a solution to the problem down the borehole. And what this did, was cause the gas to seek other paths away from the deposit. It's even possible an infrared scan would have picked up the gas, or a "sniffer" type gas meter, which can detect organics in the vicinity. Maybe the site was already leaking, and all that the borehole work did, was "disturb" what was normally a slow leak.

We have teams here, working on a continuous basis, closing down old extraction sites. There are, like, 10,000 sites with similar kinds of issues. The people who work on them, know what to pour down the hole, and how much, to close them up for the near future. It's hard to say whether every capped well is a permanent success, because things can change underground.

Fracking usually involves pumping a liquid to fracture the materials underground and free up more product. The boreholes would have material used as a lubricant perhaps, but not a defined plan to push tonnes of material below ground. Real fracking causes earthquakes (3 a day, tremblors). It makes the life of people on the surface, miserable. And this is for any site which has the geological conditions to support that movement down deep. Not every site ends up with earthquakes, but when the earthquakes come, the site has to be shut down. If nobody lives in the area, it is out in the countryside somewhere, then perhaps they just continue with the work.

Sometimes, projects like this, the original hole might have been vertical. But to cap the well, you do angle drilling from the side, to position a material to cap the main hole. There might be a couple of angled drill holes for treatment of the original hole. People in the extraction industry would know how to do this.

This particular deposit, would not gain much advantage from an angled drill hole off to the side, for decommissioning. The hole is awfully shallow.

When the incident was detected in July, everyone in the immediate area should have been evacuated, and stayed evacuated, until a proper assessment determined the "fix" was working. You can't just fart around with a live source of naturally-generated gas, with everyone cavorting next to the hole like nothing is wrong.

There is even *hydrogen* underground. Just when you thought it was safe to go outdoors. I have no idea what the characteristic depth of hydrogen would be.

and while you could place a vent pipe on site, and burn off the gas, whether that would work would depend entirely on what kind of pressure is down there, what kind of capacity. There could be a huge deposit under there.

When I graduated, one of our graduates got a job with a starting salary of $80,000 (whereas I got $35,000). Now, why would anybody pay a new grad $80K ? Well, he worked 12 hour days, in the middle of no-where, in a trailer filled with electronics. And at some distance, explosive charges would be set off, and the reflected waves coming back from layers underground, would indicate the geology of the local area. You're in the middle of no-where, no medical care, no "mall" to go to, no pub for a beer. Just you and the trailer and a salary of $80K. That's one of the ways of assessing and finding deposits underground. It had something to do with this, and charges of dynamite. And that guy was our bar manager in uni, and he had a s*it eating grin on his face, announcing his starting salary. So while ground penetrating radar can look down a relatively short distance, this kind of thing works at much longer distances.

Yes, it sounds like they capped the well but they didn't line the well. If the geology is some non-porous rock overlain by a porous rock, the non-porous would have kept the gas under pressure. Drill into it and the pressure is released. If you try to put a cap in the porous material at the top of the well, the gas will just escape via fissures in the porous rock to neighbouring properties. Which sounds like what happened to the unfortunate owner in this case - the odourless gas collected in the structure of his adjoining property and one day ignited.

Had they lined the well with something impermeable it would have prevented the gas rising up and leaking out the upper layers. But perhaps lining equipment isn't part of the gear of contractors who dig water boreholes, since they aren't in the oil and gas business.

Also there's nowhere to dig an angle drill from, unless you're planning on buying out one of the neighbours.

Theo

Yes. More so in marshes.

-- Socialism is the philosophy of failure, the creed of ignorance and the gospel of envy.

Its inherent virtue is the equal sharing of misery.

Winston Churchill

The water boreholes I have seen are definitely lined. They use a large steel pipe. There are regulations about not allowing aquifers at different depths to mix. John