Bakken (U.S.) formation oil discovery - 4 billion barrels

OilFinder2

North Dakota sets a new oil production record at 150K bpd in April.

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Look out Texas! Twisted Evil

_________________
Abundance - what a concept!

TheDude

EnergyDigger

Depends on which section of hte field your in - we use directional gamma-ray techniques to target the "sweet-spot" of the shales.... have a look at this: http://www.pathfinderlwd.com/news/2007/Encana.pdf

This is an example of Passive Ranging - a technique used for this - this was not invented by Pathfinder, we developed this with a company called Scientific Drilling - we used this in Australia while drilling coal-bed methane wells and it worked so well that a product line was developed from it - initially, all it was, was a sleeve with a 30 degree slot cut in it to focus the gamma ray - we would take 90 degree shots to determin the lowest gamma signal and then drill in that direction - very rudamentary at the time but worked like a champ - now we have computer programs that manage the mathematics without actually rolling to tool and re-shooting data - it literally takes the data at 360 degree incriments and displays the optimum way to drill - It was fun discovering this and a real satisfying effort to have an entire tool-line built up around this simple sleeve we built in Australia... at any ratem you can see we just don't "go for hte middle member" - we measure which way to go constantly.

energyDigger.com

ROCKMAN

Lots of good questions...a smart group.

Oil flow characteristics?
During the generation phase both the source rock and reservoir rock have muck better porosity and permeability. Most oil generation usually occurs at relatively shallow depths (a few thousand feet). But as the sediments are buried deeper they loose much of their ability to flow. But commonly as the source rocks are compressed during burial it's this "pressuring" of the source rock that pushes the oil out towards the eventual reservoir rock. In the case of the Bakken conditions were such that oil wasn't capable of being squeezed out sufficiently to a conventional reservoir. Thus, in this case the source rock is now the reservoir. Most of the "resource plays" you read about fall into such a category.

Bury an oil reservoir deep enough it becomes so hot that the oil will crack to natural gas.

Age of oil?
It varies quite a bit. Some of the youngest is in the Gulf of Mexico...5 to 10 million years. Saudi.....50 to 60 million years. There are oils in West Texas that are over 100 million years.

Plankton vs Trees?
Actually oils can have both marine and terrestrial sources. But marine plankton make up the great majority.

Igneous/metamorphic oil sources?
Few in the US give much though to such non-organic source. But for most of the last century most Russian and a few European did believe in a deep earth source for natural gas. The Russian were even drilling a well into the deep mantle for over 30 years trying to prove. I haven't read about it recently but the still may be drilling. I think the Swiss may have tried wuch a well also.

There are some odd ball reservoirs that produce oil from igneous rocks. There is such a field in the San Joaquin Basin near Bakersfield that rpoduces oil from a fractured igneous rock buried only a few hundered feet. But the source rock was depositied right on top of the ancient igneous rock after it had been uplifted and eroded. The only place the oil could go was down into the igneous rock. It has happened in other spots around the world and may havc spawned some early non-organic ideas.

TheDude

I was always puzzled by how seeps could exist through geologic time without reservoirs being drained. It was one of the points I might still give the abiotic crowd, being satisfied with the biogenic explanations otherwise.

How far down do deep gas fields go, too? Caught a reference to geopressured gas the other day, which apparently exists in staggering quantities.

Jean Laherrere wrote a nifty paper on clathrates etc for TOD recently: The Oil Drum: Europe | Hydrates updated. They're not as superabundant as some think, like the shrinking reserves estimates for coal, but hydrates are harder to assess. Also like coal, there's a staggering amount of them out there nonetheless.

We had a really obnoxious poster here name of OilisMastery, who was a real freak for abiotic theories.
_________________
Cogito, ergo non satis bibivi
I will not abide another toe.

ROCKMAN

Dude,

Actually your instincts regarding reservoir leakage is correct. Most oil and gas ever generated has leaked to the surface. There are hundreds of such leaks in the Gulf of Mexico right now. The conditions for oil/gas to be trapped before leaking to the surface are rare. When they are trapped it's similar to oil floating on the top of water in a bottle. If more water comes in to the bottom of the bottle the oil will flow out the top. But if you put a cap on the bottle the oil will be trapped. Geologically, impermeable shales/mudstones form these "seals" in nature.

Gas can exist quit deep. Last year I drilled a well in the Gulf of Mexico to below 34,000'.....the third deepest drilled in the western hemisphere. Not only was gas a possibility but also oil. Oil normally can't exist this deep but the temperatures are usually to high. But this was a "subsalt" well. Not only would the thick section of salt (24,000' thick) trap the hydrocarbos but also keeps the temperature low enough to preserve any oil. Unfortunately this $150 million hole didn't find any commercial oil of gas.

Yes...there are huge deposits of frozen natural gas sitting near the bottom of the GOM at depths of 5000'+. But if you take a chunk and bring it to the surface it will convert back to gas. It would be a huge engineering project to recover such gas. I'm not sure if anyone has even tried to work it out in detail. The cost would be so great I doubt it would even be considered if NG were selling for 10 times what it is now.

I don't argue with the non-organic source people. All the gas/oil I've ever drilled has been proven to have an organic source. From a logic standpoint you can't "prove" something doesn't exist (like non-organic sources)....all you can say is that you just haven't found it yet.

ROCKMAN

Good to know COR. It's been at least 10 years since I read much about the Bakken. The learning curve on all the shale resource plays have been very steep for at least the last 5 years. This is especially true of the drilling and completion technology side of the issue. Forty years ago the major oil companies would have been leading the way on such matters. Now it's the service companies carrying the load for the most part. This has helped out the smaller companies a lot. The service companies will readily tell you their "sercrets" and buy you lunch too.

EnergyDigger

Hey Rockman,

you don't drill anything dude... leave the drilling to experts - just give us an "X" like your supposed to do - LOL

Wink

energyDigger.com

ROCKMAN

ED,

I don't put X's on maps anymore. I work with the drillers now. I do pore pressure analysis. I handled the well site analysis on that 34,000' subsalt well last fall that I've mentioned before.

I like working with the drillers better than with geologists.....the drilling vendors bring better/more food in the morning. I haven't had to buy breakfast in 8 months.

EnergyDigger

LOL - your a quick study for a Geologist - welcome to the Drilling side - it does feel good huh ? Pass those breakfast burritos please...

energyDigger.com

OilFinder2

Looks like there's another target beneath the Bakken.

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ROCKMAN

OF2,

Perhaps another example of a basic point of logic: you can't prove something doesn't exist. The counter would be: you haven't looked in the right place. We'll see if this new play has legs or if it's another geologic oddity. I'll do a little online research tomorrow.

OilFinder2

OilFinder2

North Dakota production is now up to 156K bpd as of May. It's risen 13.6% over the first 5 months of the year.
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Texas is definitely getting nervous. Twisted Evil

_________________
Abundance - what a concept!