[Mettezz]

A friend of mine told me that only 33% of oil gets pumped out of an oil field.
He also said that if you increase that by 1% we wil get more oil for 5 more years.
He didn't show me any evidence of this assumption. so it's probably bullshit.

But that makes me wonder how oilfields work and how much oil they can't pump up from one oilfield.

i know that they put water inside oilfields to keep the pressure up and eventually they will only pump up water.

But how much % can they pump out of one oilfield is it really only 33%?

Or give me links where i can find some information about it please

[KillTheHumans]

A friend of mine told me that only 33% of oil gets pumped out of an oil field.

Thats a roundabout estimate for conventional oilfields. Its reasonable for an initial estimate.

He also said that if you increase that by 1% we wil get more oil for 5 more years.

The ex-head of development for Saudi ARAMCO estimated that a 10% in incremental recovery factor ( the 33% number you mention ) is good for another 33 years supply. So....1% increase = 3.3 years supply.

He didn't show me any evidence of this assumption. so it's probably bullshit.

Sounds like his numbers are in the ballpark with someone in a position to know.

i know that they put water inside oilfields to keep the pressure up and eventually they will only pump up water.

Could be. But not all oilfields are waterflooded.

But how much % can they pump out of one oilfield is it really only 33%?

At the maximum, the other 66%?

Or give me links where i can find some information about it please

We do better at wild arm waving around here rather than actual information. For the technical side of the spectrum, I would recommend OilDrum

They do much better on technical presentations.

[MonteQuest]

ASPO states that the average global recovery factor is about 30-35%. This is based on data from the IHS Energy database on 9,000 fields worldwide containing 1,400 Gb reserves.

Since this is an average, obviously some fields have higher recovery rates. Rates of 50% and even 55% have been achieved in the North Sea.

Economics and EROEI limit oil recovery to this small percentage.

[Mettezz]

Thx KillTheHumans, and montequest for replying

it's not easy to find information about things like this

[Armageddon]

It's all about the pressure too. Oil is not sucked out of the ground, its pressure forces it out. There are ways to keep this pressure going after the pressure sudsides, but it is only temporary. There comes a point when an oil well takes more energy extracting the oil out than it produces. When this happens, the well is capped. So yes, oil fields do reach a maximum point of extraction, then start to decline. This is happening all over the world, especially to major oil fields. Also, the world has peaked in conventional oil. We are now declining.

[TheDude]

The Wiki page on Oil depletion is a good start, it'll give you the basics.

[basil_hayden]

Do an experiment for yourself.

Fill a common kitchen strainer with soil. Weigh it.

Get some vegetable oil, weigh it.

Pour vegetable oil in it slowly so as to cover all the soil.

After a while, some of the oil will find its way through the strainer.
This is what is referred to as gravity drainage; that oil can be pumped.

Weigh the oil soaked soil in the strainer again.
You'll find that at least 2/3 of the oil is stuck in the soil if you distributed it well.

The oil stuck in the soil can't be pumped.
Tertiary recovery was invented to get that stuff.
Even tertiary recovery has its limits.


How does the experiment differ from reality?
The pore space in soil at the earth's surface is much higher than the pore space of host rock miles below the earth's surface.
Crude oil is much thicker (less viscous) than vegetable oil.

[rockdoc123]

The oil stuck in the soil can't be pumped.
Tertiary recovery was invented to get that stuff.
Even tertiary recovery has its limits.


How does the experiment differ from reality?
The pore space in soil at the earth's surface is much higher than the pore space of host rock miles below the earth's surface.
Crude oil is much thicker (less viscous) than vegetable oil.

Actually it would be called secondary recovery.

Pore space in some rocks is actually extremely high in the subsurface, case in point being some chalks, limestones and even some very well sorted quatrz rich sands, all of which can be in excess of 35%. A sandy soil at surface conditions for comparison would have porosity in the realm of 25 - 30%.

It isn't the porosity that governs recovery factor but rather permeability and drive mechanism. As an example reservoirs comprised of quartz rich well sorted sand can have very high matrix permeabilities (hundreds of millidarcies to darcies), if this is coupled with a very strong bottom water drive and favorable mobility ratio (the ratio of oil permeability to water permeability) then intial recovery factors can be well in excess of 40%. The 30% average recovery factor matches well to a model where a field with good reservoir characteristics and favorable mobility ratio has no water drive support and is produced under it's own power (gas depletion drive). Under secondary recovery schemes such as water injection, WAG (water and gas injection) recovery factors can get quite high (Ain Dur in Saudi Arabia is expected to reach 73% ultimate recovery from water injection). Some tertiary recovery schemes such as steam injection can also result in high recovery factors. Kern River field is currently at close to 70% recovery factor and Chevron believes they may ultimately get greater than 85%. There are other factors that come into play (wettability is one, pour point another, cloud point another), it is actually a complex story that has kept reservoir modellers busy for a long time. No two reservoirs are exactly alike so ultimate recovery from fields has a wide range.

As to the comparison of oil to vegetable oil I believe you meant to say oil is more viscous than vergetable oil, the higher the viscosity number (either in centipose or centistokes (cp*density) the more difficult it is to flow.
This is actually not always true, certainly for heavier oils where the viscosities can climb into the hundreds yes but as an example Ghawar crudes have a viscosity of about 0.6 cp at reservoir conditions....vegetable oil on the other hand at standard temperature and pressure has a viscosity of around 35 cp.

[KillTheHumans]

Now I'm a gas engineer, (gas distribution), though oil (& gas) in the ground is not my department. Very surprising figure re remaining oil (33%)

So, a hell of alot of oil will be left in each field, unrecoverable, or uneconomically unrecoverable.

(Probably daft) Question - Is there possibly a way to get the energy out of this oil, in situ. Pump air into it, aireate it & burn it underground. This happens in some coalmines, spontaneous combustion. Perhaps using heat produced to make steam. then electricity.

How about...we figure out how to produce more of it, call it something catchy, like, say "reserves growth" and keep pumping it into our cars to mitigate the transition!

10% change in recovery factor worth a TRILLION barrels or so according to Banderi.

[basil_hayden]

I was trying to keep it simple, doc, but thanks for the details, and yes I still always mix the viscosity up - that's why I put what I meant outside parenthesis. Thanks for catching that.

As an environmental geologist, among other things I work on oil spills that reach the subsurface and float on the water table. I once worked on a project that had 12 feet of floating oil on top of the water table; it bubbled to the surface as 18 wheelers drove over it. That's how the problem was discovered.

In a very permeable sandur deposit with 39% porosity and a conductivity on the order of 10E-2 cm/sec (coarse beach sand for the lay folks), the recovery of 20,000 gallons of No. 2 oil from a 60,000 gallon spill was considered a success. In other words, there was no more mobile product after the 20,000 gallons was collected. Bioremediation, surfactants and oxidizers got another estimated 5,000 gallons. The rest was excavated and brought to an asphalt batching plant. Damn big hole, about 2.5 acres 15 feet deep, or 75,000 cubic yards. The bill was even bigger.

What I don't have available that a petroleum geologist does is the drive mechanism - pressure. No confining layers of suitable thickness at the surface. I can pretty much only depend on gravity not density changes, maybe an occasional steam injection project to recover No. 6 oil which is very thick (I give up on viscosity, LOL).

20 years in the business and I'm in the 50,000 gallon club for recovered, free floating product.
Not bad when you consider a teaspoon of oil in a railcar full of water would render that water non potable according to regulatory standards. Much more than that in impacted soils.

Of course, we don't see releases of this volume often anymore. It wasn't environmental awareness that stopped the releases, it was the cost of cleanups, ask any responsible party....the first gallon comes out for 100 bucks, the last gallon comes out for about 100,000 bucks. I'd guess that relationship is inverse for the two industries, attributable to the low-hanging fruit parable.

[TheDude]

(Probably daft) Question - Is there possibly a way to get the energy out of this oil, in situ. Pump air into it, aireate it & burn it underground. This happens in some coalmines, spontaneous combustion. Perhaps using heat produced to make steam. then electricity.

Dont bite my head off please !!! - But I remember reading something similar a while ago with coalfields. Probably bugger up the local water supplies, etc so an environmental nightmare.

Here's a piece from the Oil Drum on Toe to Heel Air Injection (THAI), which uses two wells, a vertical which pumps compressed air into a fireflood, driving it (and the liquefied oil which occurs as a result) towards a horizontal producer. Don't think it would work with gas for some reason! Heaps of illustrations/descriptions/commentary in that piece. We've discussed it a bit here as well. From time to time I hear updates on it, which are suggesting it's not working out as well as hoped; perhaps they'll get the kinks out.

They'd tried fireflood methods before, too, but they were unregulated and were difficult to control, like your coal mine fires, which are quite substantial - one burning seam in China is thousands of miles long.

Hirschfactored in EOR's potential to mitigate PO, given your obvious economic constraints:



Cleaning up oil spills sounds maybe akin to Steam assisted gravity drainage. Think your business will be picking up soon, Basil? We have newfangled messes like coal bed methane to clean up. after all.

[basil_hayden]

Cleaning up oil spills sounds maybe akin to Steam assisted gravity drainage. Think your business will be picking up soon, Basil? We have newfangled messes like coal bed methane to clean up. after all.

I've moved on to primarily hazardous material cleanups. Petroleum gets boring after awhile.

Besides, if you think ethanol has a bad EROEI, you should see how low environmental remediation's EROEI is. I ought to be out of a job soon, forced to the oil fields. Not all bad I guess - environmental geology to petroleum geology is like social sevices to psychiatry, so I expect to make a much bigger salary but I may have trouble sleeping at night.

[MonteQuest]

If we cant get the oil, can we get its energy ??? Can the EROEI be overcome ?.

No, the EROEI cannot be overcome. If it takes more energy to get the oil than you get from it, you leave it in place.

Lots of gold in the ocean...but we will never get it.

And EOR just increases the decline rate of the field.

Burn it in situ? Ever hear of global climate change? We cannot continue to burn fossil fuels even if we find more or can get more from the oil fields.

That is our dilemma.

But rest assured, we will burn everything there is to be burned.

[MonteQuest]

My thread was a technical question to ask if THE ENERGY CONTENT of any remaining oil which cannot be produced, either for technological & / or economic reasons, can be released with a positive EROEI.

Gasmon

The 35% average figure is from limits due to both economical and EROEI limits.

So, the answer is no. This figure has been the average since the 1960's.

[KillTheHumans]

No, the EROEI cannot be overcome. If it takes more energy to get the oil than you get from it, you leave it in place.

Which is why in boardrooms in oil companies all over the nation when a new project comes up for review the 2nd question asked by the managers is "And what, young engineer, does the EROEI of this particular project happen to be?".

NOT! But Monte is just so CUTE when he tries this stunt with a straight face.

And EOR just increases the decline rate of the field.

More bad categorical statements there Mr Monte. EOR also increases URR which in many cases means same decline, sometimes LESS DECLINE! And......MORE OIL!!! Like..say...Yates and Ghawar? Gee....not much extra oil involved in those ones! Kern River and Midway Sunset? Yup...bigger declines for certain! And Belridge? You betcha!! If those are steeper decline from EOR, I say we need more of them!

[KillTheHumans]

The 35% average figure is from limits due to both economical and EROEI limits.

So, the answer is no. This figure has been the average since the 1960's.

35% recovery from primary production has nothing to do with EROEI limits, go read what RocDoc said, its more a function of the drive and the geology, including permeability.

And I think the recovery being 35% on average for 45 years is a load of bull as well....I can't see how that could happen considering the direction of overall recovery factors without using lower recovery efficiencies from unconventionals to keep the overall average down, and since Monte probably doesn't have access to that info and wouldn't know what to do with it if he did, I'm betting he's just making stuff up....again.

[MonteQuest]

35% recovery from primary production has nothing to do with EROEI limits, go read what RocDoc said, its more a function of the drive and the geology, including permeability.

Primary prioduction only yields about 15 to 20%, not 35%.

It's only after secondary and tertiary or EOR that the 35% average figure is obtained.

And I think the recovery being 35% on average for 45 years is a load of bull as well....I can't see how that could happen considering the direction of overall recovery factors without using lower recovery efficiencies from unconventionals to keep the overall average down, and since Monte probably doesn't have access to that info and wouldn't know what to do with it if he did, I'm betting he's just making stuff up....again.

Naw, just a typo error. Should have read 1990's.

Point being made is that we are not raising that average with technology.