[SteveM68]

Hello,
I'm new to this forum and hoping someone might shed some light on a concept that is frustrating me. I recently read that 43 billion barrels of stranded oil in the US might be recoverable using tertiary CO2 injection etc... If I understood the article correctly (posted on this site) the increased profits have made this type of recovery feasible. Does anyone know if this is true? Is the US government moving towards a larger focus on recovering this stranded oil? And, are other countries and oil companies also focusing on recovering this otherwise stranded oil, now that they apparantely have the money to do so? Has there been some advancement in this process, or is it just that it's financialy feasible with the higher oil prices/ profits? Could this push the peak further into the future? My gut instinct is telling me it sounds a little too good to be true, but I'm trying to be as objective as possible. This is a great website. I have been reading what I can and trying to put this puzzle together for a few months now. Any information on this topic would be extremely appreciated. Thanks. -- Steve --

[backstop]

Steve -

Welcome to the site.

43 Bn bbls sounds impressive, and no doubt was meant to by its author, but it has to be seen in context to get any useful idea of its relevance.

So, if such a resource actually remains in the US,

and if it proved recoverable both technically and financially, despite the escalation of extraction costs due to rising energy prices, rig demand, etc,

then at present usage of ~ 84m bbls/day

it would in total provide 512 days of global oil suppy.

But if it were only 40% recoverable (as is more normal), that falls to 205 days.

Or if, given the massive effort already put into emptying US reserves, only 15% is recoverable, it would supply just 77 days of present global usage.

My guess is that rising extraction costs will be the key factor here.

regards,

Backstop

[netfind]

Steve - Stranded oil is a geologic fact of life that reservoir engineers wrestle with as part of their job description. In the life of an oil field, you basically have oil discovered sitting on top of water (oil is lighter than water), wells punched into the domes where the bouyancy of the water can push the oil out of the ground, and then a very, very slow, controlled advance of the oil/water contact "membrane" over the decades of the usefull life of the reservoir. As the waterflood advances all the way to the top of the reservoir, more and more of the water finds its way through cracks, soft spots, and other anomalies bypassing pockets of oil bearing rock. This produces water flow along with the oil flow out of the wells or "water cut", which is the % of the well flow that's water. By the time the water sweep has nearly run it's course, the water cut has gone from about 10% at the start to 40% or more. Once the field "waters out", oil companies normally move on to newer fields for their bread and butter and install tertiary recovery at these spent fields such as the artificial lift pumps, C02, etc. to coax the stranded oil out. The very big problem with this stranded oil is that it will never be recovered at the high flow rates of primary recovery from a highly pressurized reservoir (3000 psi or so). There's a lot of it, typically the primary recovery gets only about 40% to 65% of the URR (ultimate recoverable resource). But after the reservoir has fizzled, the rest has to be recovered at a trickle if it's recovered at all.
This oil bypassing problem doesn't get much consideration by energy planners and such, but it seems to me that it will produce some ugly surprises. Oil field techs control the water advance and thus the production rate by choking the wells. If you open the thottle too wide for too long, the water advances too fast and much more oil is bypassed. This was a big problem back in the 70s when a decade long demand surge caused OPEC, the swing producer, to overproduce their giant fields; and I think the other elephant producer we depend on heavily today, Russia, may have been seriously overproduced then too. It was so bad, there were secret Congressional hearings in '74 and '79 on Saudi reservoir overproduction and damage being done by the four American majors that were then running Aramco, Saudi Arabia's national oil company (see Simmons' documentation of this in Twilight in the Desert). This probably stranded a lot of oil that everyone seems to think is coming at the high flow rates we've been spoiled by. This is important as we get very close to major fields like the Saudi Ghawar watering out. When pitted against the climbing demand curve, what's important is the RATE of oil coming out of the ground, not how much eventually comes out.

Hope this helps your understanding of stranded oil even if it doesn't brighten your outlook for oil pricing.

[rockdoc123]

netfind....you seem to understand some of the science but there are either misconceptions here or you just chose to leave some very important facts out. First of all if a field is under water flood (the example you gave) it is not primary recovery...which really refers to that recovery one would get without intervention. If you needed to use the water to replace reservoir pressure then it is likely the field was originally producing under gas depletion drive....primary recovery usually less than 30%. If on the other hand the field has an active water drive...you do not usually need to inject additional water and the overall primary recovery without intervention is about 40% or higher.
In terms of the normal technology for producing high water influx your understanding of the technology is a number of years out of date. Most commonly horizontal wells are used to achieve high rates at low drawdown which keeps water from coning. Where there are specific high permeability zones which bring in water via bypassing these are usually shut off with a number of methods. This is the technology being used in Ghawar presently. Contrary to popular belief from what I have read in various SPE publications Ghawar is not ready to water out...indeed about 60% of current production comes from behind the front of the flood and they have been able to maintain water cut at about 30%.
The important issue about rates is simply that if you can deal with the water there is nothing to keep you from keeping net oil production high. Many fields produce at extremely high water cuts...the overall field rates are kept high by having larger and larger water handling capacity in the field. The high rates are achieveable but only at higher costs.

[SteveM68]

Just wanted to say thanks for the responses. I'm going through Matt Simmon's book right now and it is excellent...though extremely disconcerting. Anyway, I do appreciate the information. Back to trying to piece this thing together. Scary stuff.

[BKWorldEnergy]

Just wanted to say thanks for the responses. I'm going through Matt Simmon's book right now and it is excellent...though extremely disconcerting. Anyway, I do appreciate the information. Back to trying to piece this thing together. Scary stuff.

Matt intended it to be disconcerting. But he is also not a resovior engineer, which he will freely admit.

Make no mistake: in this high priced environment, lots of "smaller" plays look good to independants with low overhead. How much i "stranded" is like the guy from the ozarks said, dependant on technology and therefore money.

Essentailly no formation is 100% recoverable, but anyone who tells you that developing 200 days of global oil supply isn't worth doing is not worth it is not really thinking about the economics of resource development in a macro level at $60USD a barrell. In other words, yes it's going to run out, but might as well use what we have.