One comment on your base case production model is that the production rates in 2007 to about 2010 may be too high. I know that you may not agree.

Ace - I actaully agree with this. If you worked out the decline rates as a function of declining sub-areas (e.g. N Ain Dar) then you will get even higher decline rates and it wouldn't surprise me if the Saudis cut right back on production in these areas to protect the reservoir and allow resegregation of oil and water. This is actually what I've said from the outset - that recent production declines may be in part voluntary aimed at resting tired reservoirs. So if anyone wanted to build a voluntary reservoir management restraint function in here and have decline starting earlier and proceeding more gently I'd agree that was a sensible approach.

Following your decline rate model you maybe want to view the field as two halves - a rapidly declining North and a stable (growing?) South.

Where has this resting of wells been practiced?

Hello Euan and Ace,

The Voelker PDF goes into great detail on qualifying backflow, DFN coning, and zonal thieving problems encountered during shut-in/resting periods, but unfortunately doesn't give us any quantifying detail on the areal extent of these DFNs/per Ghawar subfield. A glimpse is only provided on page 66, frame 96:
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A specific example[51] which has implications on the geometry of the thin, permeable facies associated with super-k, is that of an Uthmaniyah well which backflowed
over 1000 B/D upon shut-in, into a thin interval located at the top of Zone 2A, a common stratigraphic location of super-k intervals (5.4.2).
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The best waterfront glimpse is provided for UTMN circa [2000-01] in the MORABT map page 76, frame 106. Sure would be nice to have this for the entirety of Ghawar to see how much would be green area in 2007.

Bob Shaw in Phx,Az Are Humans Smarter than Yeast?

Hi Euan,

Thnaks for that suggestion, I will break Ghawar into sub fields for forecasting in my model.

In your base model forecast you show both North and South Ain Dar having no forecast production in 2013. Do you think that North and South Ain Dar will be abandoned completely or will they continue producing some kind of hydrocarbons (oil, NGL, gas)?

My guess is that they may start a massive program of tertiary recovery using gas injection. So in reality production may go on for decades at a greatly reduced rate. They can also have a program of infill drilling - the well spacings here are still enormous. And they can opt for infield water injection - i.e. injecting water into swept zones to improve sweep efficiency. So my forecast is really just for the final stage of dry oil production with associated wet area production.