The Oil Drum

One of the side benefits of attending the World Oil meeting in Denver last week was that I could pick up a few of the DVD's that Global Public Media had available including a long interview with Colin Campbell.  Watching the first half of that tonight, I was reminded by him, that while we are discussing the depletion rates for oil, the more critical one for immediate attention is that for natural gas.

When one taps an oil reservoir the oil requires a certain amount of differential pressure to push it towards the well, and with the passages it must pass being generally narrow, flow is relatively constricted.  Good well management means that, in order to control water and gas problems, the pressure difference between the well and the rock is carefully controlled, and this allows the oil to be effectively recovered at rates which, while worryingly increasing, are still generally considered to be less than 10%..

Natural gas, on the other hand, flows a lot more easily, and normally does not have a lot of the constraints that producing oil has.  Thus, if your pipeline can handle the flow, and there is a demand, the gas field can be drained much more rapidly, with a consequent dramatically more rapid conclusion to the flow.  As Dr Campbell pointed out fields may last just months, and then "boom" they are gone.