Question about oil mining and earth cavities

My question may be answered easily by some but I will pose it anyway.
When the Oil is pumped out from the earth, it leaves huge empty cavities behind. Would this not make the earth, or more precisely the crust unstable? Could this be why earthquakes are on the rise?
I know some will say that we pump water into the cavity to make the oil rise for easier pumping but the properties of water are not the same as oil so I still feel there would be some instability, wouldnt water eventually seep?
Another question on this matter is, even if the water technique was used, we couldn't completey fill the massive void created so if the oil and/or gases remaining were to ignite this could potentially be disasterous for the planet?

I remember speaking to an OIL driller about his job. After listening to him bragging about how much money he earned i got a bit annoyed so i posed the very question you are asking and he took the huff and shut up. They don,t pump in water they pump in drilling mud to push the oil to the surface. The mud is heavier than oil so it sinks to the bottom and pushes the oil to the surface so they can extract as much oil as possible. What they don,t tell you that the drilling mud is toxic also there is huge gaps left because the can,t fill the well up completely leaving huge caverns which could possibly collapse and release gas and oil in vast quantities into the sea. As they cannot get all the oil in a well because they lose pressure after they have taken so much and the well becomes inviable. All it would take was an earthquake in the right spot to collapse it and it would create gas clouds,oil slicks and toxic mud dissolving that rise,s to the surface causing an ecological meltdown. Which they would not be able to stop because of the vast area it would cover. Think for instance how much a milllion barrels of oil would cover land wise and you get the picture. That,s why they always cap wells so this does not happen. The OIL companies always tell us that this can never happen saying that it never has far as i know. I have never heard of an Oil rig collapsing into the sea and they are huge weights 10000 tons upwards. It could be something that takes a long geological time to happen as the earth,s crust moves or a big enough body that passes close enough to the earth to cause changes in the mantle of the earth. We really could have hell on earth sea,s boiling rain that is on fire what it says in the bible fire and brimstone and so forth. I think there is potential for something like this to happen in the future. I am no scientist so i am speaking in general terms. I have experience in the oil industry so i know general info about the industry. Most people are ignorant to these facts and big oil will not speak about it or just laugh it off

I might be able to answer as I used to work for a well service company.

First your talking about two different things. one we do what's called a hydro frac to improve well flow that's not done with water but rather a mix of sand and gel... I'll talk more about that in a second...

the other thing we do to pressurize a well is to pump Nitrogen and CO2 down into the oil bearing layer. the gas is very cold and in liquid form so as it heats and expands it pressurizes the field...

Okay now oil if not down in some deep cave... the earth is made up in layers and the layer that traps oil tends to be a sediment layer...kind of like a sponge... the earth above that layer puts pressure on that sponge and when you put a pipe into it you get oil flowing out....

Now these layers are not always perfect so a company will come in and under great pressure (I've seen up to 10,000 psi) pump in an artificial layer of sand... the pressure cracks the earth injects the sand and creates a layer for the oil to flow much easier...

no one whats to drill into a cave... Up in Wyoming I worked on a rig where at 24,000 feet we drilled into a cave complex and all we got back was H2S a poison gas...

if you want a real conspiracy then look back at the records for the 70's and 80's... thousands of gas and oil well's were drilled throughout the western US then capped... for a while there it cost more to pump out the oil than what it was worth... the government basically paid oil companies to sink new wells and they did... but never pumped them... I should know as I worked on the crew that went on and capped those wells...

Anyway there's no problem with some huge cave ready to swallow a city...
But there are places in the world where coal mine fires have cause the ground to sink and heat up...
Vid of Frac job

[edit on 3-4-2008 by DaddyBare]

[edit on 3-4-2008 by DaddyBare]

[edit on 3-4-2008 by DaddyBare]

Thanks guys.
As someone who doesnt know much about the industry but is a curios observer, I find it intersting that 2 people with hand on experience have 2 different answers. Both are credible and both reasure me that with the practices we are still potentially screwed, although Daddybares described method is somewhat safer, so i like that one.
I dont want to say either are right or wrong, but the fact we have two different explainations from 2 replys does scare me a little. Is what we are being told by the big boys and what is happening the same thing?

Whoa there I never said it was safe!!!!
if you work in the biz the first thing they teach you is how to work and stay alive in a poison gas environments!!!!

Hydrogen Sulfide (H2S) is the most common one and one breath kills!
Hydrogen sulfide has been implicated in some of the five mass extinctions that have occurred in the Earth's past.....
to this day if you travel past some of the wells in west Texas and Western Wyoming you might just find dead birds and sometimes cows lying around a well head... the really dirty wells will have a flare tower to burn off the H2S gas... that burn gets you another poison gas called SO2 Sulfur dioxide...slightly less deadly but easier to handle... meaning S02 is lighter then air where H2S is Heaver and stays on the ground.... I've only once heard of an entire (small town) needing to be evacuated due to gas... But hearing about crews dieing from exposure is not all that uncommon...

Oh no I never said Drilling didn't pose a big risk... All I pointed out was you were wrong about there being big caves left after the oil is gone...

reply to post by DaddyBare

Sorry, I may not have expressed myself properly. In terms of the earth collapsing exploding etc your explaination is safer earth structure wise, but as I said. We still seem to be screwed no matter what.
It seems funny to me that although there are still hugh risks environmentaly the value of oil still seems worth it to the oil companies.
I am not by any means a 'greeny' but as more info comes to light these days I can see we are determind to destroy ourselves one way or another.

The only way out is nuclear. Oil will sustain us for a few decades at the very least, so we should, in my opinion, use that time and energy to build up some nuclear plants in North America. Windmills, solar panels, etcetera sound nice and green and will sway the sheep into voting for whoever built them, but realistically, nuclear is the answer.

I believe there is some plans to nanoengineer some hyperefficient solar panels but for now that is far off in the future. Also, certain bacteria can reportedly be genetically engineered to eat oil then self-destruct, making spill cleanup a breeze.