The Oil Drum

345 comments on DrumBeat: October 18, 2006

Comments can no longer be added to this story.

PhilRelig on October 18, 2006 - 8:26am

I also have a second question about how field size relates to the lifetime of the field. Ghawar has a total lifetime of significant extraction spanning many decades, while fields in the North Sea have a lifetime of significant extraction that seems to be significantly shorter - maybe two decades, rather than 8. And I get the impression that smaller fields often have a lifetime of significant extraction that is even less than a decade.

I guess my question is this: Is there some kind of mathematical rule-of-thumb that relates OOIP to significant extraction lifetime, or that perhaps relates the physical dimensions of the field (in 3D, underground) to significant extraction lifetime?

Comments can no longer be added to this story.

elwoodelmore on October 18, 2006 - 6:17pm

well it appears no one is going to respond so i'll take a stab at it the size of a field depends on the volume of rock areal extent x net thickness the porosity, water saturation and fluid skrinkage (from reservoir to stock tank) the rate of production is a function of the well density wellbore size and orientation (ie horizontal or vertical) completion techniques possibly artificial lift (type of pump if any) permeability of the rock (which is generally a function of porosity) fluid viscosity and pressure and reservoir drive mechanism ( solution gas water drive gravity drainage) and possibly pressure maintainance techniques some of these factors are interrellated but i suppose to answer your question every field is a different animal the producer will generally try to operate the field in such a way as to maximize financial return (at least what they believe to be optimum)

Comments can no longer be added to this story.

PhilRelig on October 18, 2006 - 10:59pm

Thanks for your response. But how flexible are all these variables? Could Ghawar, for example, have been substantially exhausted within 10 years of the first well drilled if there had been 50 or 100 times as many wells drilled as there actually were?

Comments can no longer be added to this story.

sendoilplease on October 18, 2006 - 11:19pm

In a nutshell - yes.

The more straws in the milkshake, the sooner you hear the slurping sounds.

But if some slurpers get head-freeze and their consumption drops there will be a delay until you hear the slurping sounds. And if one person is a head-freeze recessive mutant and therefore can suck down the milkshake at a rate 10X that of everyone else...

sluuuuurrrrrrrrrrrrrp!**