The Oil Drum

Conrad, actually no, I posted the above in response to elwoodelmore's post on yesterday's Drumbeat, early this morning:

the field pressure may have been supported for a significant part of its life by water influx from a huge aquifer. after decades of oil production the aquifer probably could no longer keep up so at some point the saudi's decided to use sea water injection for "pressure maintenance"

I only wished to point out, but without putting down elwoodelmore, that this was simply incorrect. Saudi has been using water injection for half a century. This is not unusual. Water injection is now in common use around the world to keep the pressure on reservoirs.

The increasing water to oil ratio indicates that the field is in decline. When Saudi starts increasing the water injection you can be sure they have a very good reason for doing so. This is all part of their effort to improve the decline rate of their giant fields from an average of 8% to 2%. And of course this will probably work....for awhile. But sooner or later that 2% will catch up with the 8%. That means that a field will likely go into catastrophic decline at some point.

One more interesting point that I just thought of. Abqaiq was the first Saudi field to receive water injection. Abqaiq is now completely watered out and Saudi is now trying to milk pockets in Abqaiq to get the very last drops of oil form her.

Ghawar was the second Saudi field to receive water injection.

Ron Patterson