Geology question: Why is the oil gushing?

[asterroc]

Okay, someone explain to me, why is the oil gushing out of the well? I picture the oil as being inside an underground lake, with the well being like a straw going down to it. But when you put a straw into a glass of juice, the juice doesn't suddenly start gushing up the straw, it sits inside the glass until you start sucking on the straw. In the case of a juice box, the juice does start gushing out of the juice box, but that's because you're squeezing on the package while holding it to jam in the straw - is there something "squeezing" on the oil in the ground? Or is it heat causing the pressure, and if so then why hasn't all the oil leaked out and stabilized that way?

Comments

[zandperl.livejournal.com]

Oh okay, so in the process of tectonics, the reservoir is put under pressure, but the reservoir doesn't have sufficient holes out for the oil to significantly leak out that way. Then when you drill the well, the oil gets pushed out that way by the pressure, and usually the well is built so that it doesn't gush, but this one failed and it is gushing.

It reminds me a bit of rubber/latex or Mylar balloons. Rubber/latex balloons the material is slightly permeable so the air can leak out slowly, and Mylar balloons have microscopic holes which also allow the air to leak out slowly. This might be happening with oil reservoirs, but it's nothing significant. Then if you poke a hole or drill a well it all comes gushing out.