On Mon, 28 Jun 2010 06:45:39 +0000 (UTC), Przemek Klosowski
wrote:

On Sat, 26 Jun 2010 17:10:10 -0400, Ed Huntress wrote:

"Azotic" wrote:

stated that a huge underground lake of methane gas-compressed by a
pressure of 100,000 pounds per square inch (psi)

Well, I would like to see the source of that number. The oil is at 18000
ft, of which 5000 ft is water (1 g/cm3) and 13000 ft is rock (say 2.7 g/
cm3). From the simplistic 'column of stuff' argument, the pressure of oil
(0.5 g/cm3) at the sea bottom will be .448 [psi/ft] times (5000 ft +
13000 ft * (2.7-0.5)), which comes out to 15000 psi, which agrees with
what I have heard on the TV about the pressure of oil spurting from the
well head.

Why would gas be under dramatically different pressure? Rock is porous, so
if it wasn't equilibrated by the simple depth-related pressure, it would
diffuse away.

The articles claiming 1e5 psi tended to have alarmist titles like 'Gulf
disaster could kill millions' so my BS detector needle pegged on red.


Some rock is porous and some is not. In most cases gas is found in
association with oil and often is dissolved in the oil and separates
when oil is brought to the surface and the pressure drops to ambient.
In other cases relatively pure gas is found as a gas cap on top of an
oil reservoir, or even alone or with insignificant amounts of liquids.

Mobile's field in N. Sumatra and Hufco's field in Kalimantan are both
gas deposits with insignificant amounts of associated liquids.

I remember quite a long time ago (20 years ago, maybe) there was some
high pressure sour gas finds on the coast of Louisiana (I think) that
were plugged and abandoned since at the time there was no way to
produce the levels of high pressure, corrosive, gas economically.

I think the point is that the well was completed and the rig was
preparing to move off. No mention of extremely high pressure gas had
been made at that time.

Another thing that seems to go unnoticed is that much of the talk
about missing centralizers and amounts of cement pumped seems to be
coming from the cement company who did the cement job, and possibly
can be found liable if the cement job is found to have failed; almost
like someone laying out the defense before the charges are made.

Cheers,

John D. Slocomb
(jdslocombatgmail)