179 comments on And how is Saudi Arabia getting on? (or more evidence of a deteriorating situation...)
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k Nation (Jim Kunstler)
GAIA Host Collective
I addressed the Ghawar Field over in the open thread, but IMO it is highly misleading for the Saudis to be talking about increased recovery factors in many of these fields because in a lot of cases, the oil left behind is largely immovable, after the oil/water contact rises.
For example, East Texas has a 99% water cut. Daqing has a 90% water cut. Prudhoe Bay has a 75% water cut. Cantarell is crashing, with up to a 40% annual decline rate ahead. As I noted over on the open thread, the best case for Ghawar is that it has a 35% water cut, after being redeveloped with horizontal wells.
After you redevelop with horizontal wells, and if you are still getting a one-third water cut in a rapidly thinning oil column, what else is left in the bag of tricks?
Convert to gas production.
WT, the only other possibilities I can think of-and they are unproven and possibly reckless to use on the worlds greatest oil field are some type of surficants to cut the immobile oil out of the reservoir rock or possibly microbiological enhancement, injecting bugs that will lower the viscosity of the crude.
But surely Allah isn't going to desert us now!
I wonder, if the source rock is some sort of carbonate, could you collapse the pores by flooding with some acid solution, maybe followed by a shock wave? The oil would be wrung out like water from a sponge.
The reservoir rock in Ghawar is a carbonate. A dose of acid serves to open up new paths for fluids [both water and oil] to the well bore. This is usually useful only when the permiability of the reservoir rock is low. If you only have the very top of the formation open either through a conventional completion, a horizontal bottle brush smart well, or whatever -- opening up the formation probably means opening it up vertically as well as horizontally. The result would in most instances be even more water.
In a test tube, you could disolve a chunk of the reservoir rock with acid, but you would also do bad things to the immobile contained hydrocarbons ... and even if the acid wouldn't digest the oil this approach would be completely uneconomic in a real world setting as the reservoir by volume is probably in excess of 85% rock; the contained water dilutes acid; a lot of the fluid you obtained would be water; and [if your theory actuall worked] "collapsed" pores would equate to zero permiablity / porosity in the vacinity of the well bore.
If you really wanted to try to improve the oil cut you could try a "polymer job", but that approach wouldn't get you a thousand barrel a day well water free well by any stretch of the imagination. BTW, my limited experience with polymer treatments has not been good, but they are in certain instances very useful in extending the economic life of a well.
As I also mentioned in the open thread, Ghawar has been running close to a 35% water cut since about 1999. So if in fact they are still at 35%, then that's a very good sign for them and indicates that no precipitous decline is in the works.
Which is exactly what Shell thought, as they were expanding their surface production facilities to handle an expected flood of new oil from the Yibal Field, when instead they got an unexpected flood of new water. Yibal, like Ghawar, was redeveloped with horizontal wells. Why? Because the vertical wells in both fields watered out.
Nope, nothing to worry about here. Go about your business. Go ahead and buy a new SUV to drive to and from your McMansion. I need still need to pay for this year's European vacation.
You make it sound like Shell invested millions of dollars in production capacity that never turn into fruition. This sure did not happen.
Shell's investments in the Yibal field did yield increase oil production, but as you pointed out, 90% water cut started showing up in some wells and Shell had to shelve any new investment to increase production capacity. They instead got stuck with ever higher production costs due to high levels of water.
The lesson here is that Shell's investment in enhanced recovery technology did not increase total ultimate recoverable oil, but instead speed up oil production for a short period before dropping. Yibal is a great example where new technology failed, but is not a good example of showing oil companies not meeting their short term projection as they sure did meet their short term capacity projections.
They aren't still at 35% water cut.. Its fallenby some 7-8% since 1997