[Permanently_Baffled]

Good evening all.

Right, I need to ask some more questions. These are genuine questions as I do not fully understand the process of oil extraction. Please do not flame me to death , I'm just trying to learn (I feel like a Burger king burger sometimes )

From what I read on this site (and others) one of the biggest fears is that oil producers like SA, Iran , Kuwait , UAE etc etc will face rapid decline rates because of using MRE methods to extract their oil. This allows maximum short term production, but then the field declines faster and reduces the URR of the field. This means that post peak we could be facing Year on Year decline rates of 10% +! Which in short , means we are all screwed...

Now this is where I have the problems understanding. Apart from the last 2 years or so , many oil producers (mainly OPEC) were producing way under there production maximums because of the slump in the price throughout he 80's and 90's. So why would they use MRE methods? Surely if oil producers are producing way below there capacity, by definition, they are not using MRE? If this is the case, the decline rate would be slower post peak?

My next query is that of the US. Now I can understand that there average decline rate since 1970 has been aided by new GOM and Alaskan production. However both of these areas have been in decline for sometime and yet decline rates have still been in the 1.5-3% rate per year. This is despite the US pumping at FULL CAPACITY throughout the 80's and 90's UNLIKE OPEC producers!

Lastly, why doesnt the US use MRE and the other producers do?

I am not challenging the mighty Simmons , I am just trying to understand.

I hope I am asking question others were to afraid to ask !

PB

[Permanently_Baffled]

FFS no responses?

Cmon Aaron , I know you must have the answer to this one !(if you don't mind )

PB

[Hawkcreek]

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[Antimatter]

MRE is a bit of a broad brush - the Saudi's do use branced horizontal wells and water flood but this is nothing unusual. Horizontals allow you to contact more of the reseivour and hence extract more oil with less wells (usually lower capital cost and much lower footprint than drilling lots of verticals). 4D seismic allows you to track the flow of oil in the reservior and perform infill drilling to catch pockets that would otherwise have been bypassed. Water injection typically adds several percentage points to ultimate recovery especially peripheral injection (as the Saudi's claim they do). Technology does allow a feild to be drained faster but i don't know where the idea that it decreases ultimate recovery comes from.

[Aaron]

$this->bbcode_second_pass_quote('Permanently_Baffled', 'F')FS no responses?

Cmon Aaron , I know you must have the answer to this one !(if you don't mind )

PB

[shakespear1]

The Ultimate Recovery is not a fixed number which we aim and reach. If you look at how it is arrived at and what controls it you will be amazed that we even come close to what we predict.

Assuming we know this number from God and produce the field at OPTIMUM RATES at each well we will hit this number.

What does OPTIMUM mean? This will be a TOTAL rate that will allow you to produce oil for the longest time before water/gas starts to come into the flow stream at the well. Remember, there is always water around ( bottom ) and there may be gas ( above ). These phases want to flow also and will eventually.

The rates of the oil/water/gas phases will vary depending on the bottom hole pressure you are maintaining at the well. If you lower this pressure below OPTIMUM then water/gas will start to flow faster toward the well. This is because of viscosity differences and something we call relative permeability of the particular phase.

Viscosity is easy to understand but the relative permeability may be harder. The word relative implies permeability the phase sees due to interference of the other phase next to it. In simple words, when oil and water flow together they bump each other like people on a plaza and thus slow each other down.

So ramping up rates can move you away from the OPTIMUM Recovery and you may never get back to it even if you turn the rates down after a year or two of doing this. Why? Because once water or gas creates its channels of preferred flow the oil left behind will not easily come to the well any more. It is LOST behind. Maybe after a million years this will all come to a new equilibrium and then you can start again, but by that time we will have figured out how to live on air alone.