Pressure from petroleum wells...

[Externet]

I read the infamous well in the gulf flowed with 6000 psi

 

What causes such high pressure? Is the weight of the earth crust squeezing the petroleum filled pockets down, compressing it ?

[cypress]

It is primarily the static head of the water column though in some cases the liquid in the pore space supports the geologic formations and thus they contribute as geopresured zones.

[Externet]

From water column, the pressure at 1 mile depth is only 2360 psi

[cypress]

From water column, the pressure at 1 mile depth is only 2360 psi

 

The reservoir was another 13,000 no 16,500 feet below the sea floor.

Edited August 6, 2010 by cypress

[CaptainPanic]

Logically, it should just be the weight of the water and the rock/mud/whatever that is on top of the oil/gas field.

In addition, the chemicals present in the oil/gas have a vapor pressure at the temperature in the field.

Finally, over the years, the pressure may have increased because of certain reactions... but only if the field is completely closed.

 

Anticipating the next question: why does the oil come out of the well with such force?

Because the weight of 1 mile sea, and another mile of rock is a lot more than a column of just 2 miles of oil. So, the static pressure inside the field is much more than the static pressure inside the well (inside the drilled hole that's now full of oil and gas)... and that pressure difference drives the oil out.

 

Finally... when fields become empty, oil companies sometimes pump CO2 or water (possibly turning into steam) into a field on one end, to force the oil or gas out on the other end of the field. In that case, the pressure in the well is obviously artificially increased by pumps/turbines.

[cypress]

Logically, it should just be the weight of the water and the rock/mud/whatever that is on top of the oil/gas field.

 

Most reservoirs are not geopresured, in that the rock lattice structure supports the rock over burden. In these cases, the pressure is closely a function of the hydrostatic pressure.

 

In addition, the chemicals present in the oil/gas have a vapor pressure at the temperature in the field.

Finally, over the years, the pressure may have increased because of certain reactions... but only if the field is completely closed.

 

Most reservoirs are not closed in from underneath and have a contiguous but tortuous pore space path to the surface generally filled with mineral laden water.

[DrWalter]

I totally agree with you, but, generally, pressure can have totally different profile. However, for some systems it is possible to observe stabilization of pressure and this fact been used for development of new technology. You can find literature here http://www.oladyshki...nfilov_2005.pdf