Natural Gas Slows Oil Leak in Gulf of Mexico

"BP today took ABC News to the mouth of the Mississippi to see Hazmat teams it has mobilized on the outer marshes of the Mississippi Delta, one of three locations where oil has now breached the booms and come ashore."

"It's ball sand goblets of tarish grease-like material," said Cory Anderson of the U.S. Environmental Corp."

Depletion below bubble point would be my guess

An oil reservoir can typically be what they call undersaturated, meaning it contains disolved gas bubbles within the oil volume. In this instance the pressure in the subsurface reservoir is higher than the "bubble point", the pressure at which the dissolved gas comes out of solution. When a well is producing from an undersaturated reservoir the pressure downhole is dropping and if produced long enough (and without any pressure support) will eventually drop below the bubble point and the gas will begin to come out of solution downhole and the rate of gas production will start to increase dramatically while the rate of oil production will decline. The viscosity of the oil will also increase because it no longer contains the very low viscosity gas bubbles. This is likely whats happening at this well.

No i wouldnt say that. Essentially the oil on the surface is the same. Its just that downhole the properties of the oil are becoming less conducive to oil flowing into the wellbore and more conducive to gas flow. The oil is becoming more viscous and the gas is preferentially flowing through the pores of the reservoir relative to oil.

Are you suggesting the reservoir pressure has already dropped below bbl. pt.? Not saying that's impossible, but that's pretty quick. I'm not sure if I'm buying that...

quote:

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and it also can dramatically cut the total volume of oil you can expect to produce from a reservoir, as a significant volume of it now becomes trapped within the reservoir rock pore spaces.

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and that is what is the case in Pennsylvania and Oklahoma
where oil was discovered before good engineering was law.
90% of the oil of Pennsylvania is still in the rock.

Perhaps the well penetration was already near the gas cap in a depletion drive reservoir, and the gas cap drive is taking over. Without knowing much about the reservoir size, depositional system, etc. these are just wild guesses. It just seems hard to envision evolved gas below the bubble point taking over after a couple of weeks - the dispersed gas bubbles would still have to reach a critical saturation to migrate through the reservoir. Maybe I need to go back to school on this one. The simple answer would be that the well has not turned to gas and is just experiencing reduced oil flow for one reason or another.