Question for the Geologists

[badatusrnames]

I'm looking at a regular core report, and would appreciate some help in deciphering some abbreviations:

-FD:HRTL FRAC. I'm assuming horizontal fracture for the second bit, but confirming this would be pretty important. I'm unsure what the FD means.
-SH LAM. I'm guessing shale lamination?
-CALC. Calcite? Calcareous?
-PYR. Pyrite?
-SHY. Shaley?

Any insight is much appreciated! I'm just a dumb engineer.

[msommers]

FD - Full Diameter core vs. plug analysis
Calc - calcareous

Everyone else looks fine.

[badatusrnames]

Originally posted by msommers
FD - Full Diameter core vs. plug analysis
Calc - calcareous

Everyone else looks fine.

If there's one thing you can count on, it's a geologist willing to talk about geology with others.

Thanks a lot!

[Crymson]

Originally posted by badatusrnames


If there's one thing you can count on, it's a geologist willing to talk about geology with others.

Thanks a lot!

Lol. Always true. Throw in excessive ammounts of alcohol and you have the full geologist experience.

[msommers]

It's probably our inner nerd surfacing. Which is exacerbated when the liquor comes out :rofl:

Not to perpetuate the stigma, but as an aside, if you have horizontal fractures (natural or induced from coring) and your core analysis has it, it's the reason why your K90 is much higher than your Kvert (permeability directions).

[badatusrnames]

Originally posted by msommers
Not to perpetuate the stigma, but as an aside, if you have horizontal fractures (natural or induced from coring) and your core analysis has it, it's the reason why your K90 is much higher than your Kvert (permeability directions).

Edit, hold on, wrong picture.

[badatusrnames]

I didn't see much permeability anisotropy between Kmax and K90:

http://i.imgur.com/J6NoF.png

Here's K90 and Kv:

http://i.imgur.com/jEfsP.png

Kv/K90 averages 10%. I assumed that had to do with the shale laminations acting as a vertical flow barrier. Also, can't horizontal permeability tend to be higher than vertical due to mechanisms during deposition? Ie. if it's a channel sand, it's been laid down by a body of water flowing horizontally, leading to higher permeability in that direction, with lower vertical perm due to bedding? I'm just making stuff up here though

Since it's a basic report pulled off of public data, there really isn't any information about fracture orientation, how extensive it is, etc. It was also noted in only about 10% of the intervals. Literature doesn't talk about natural fracturing in the area (Lower Manville, Dina sand).

And that's another uncertainty, natural fractures, or from coring?

Project's almost done, semester's almost done, degree's almost done. I almost don't care anymore though.

[msommers]

I'll take a look later as the pictures are being blocked right now.

Kvert/K90, I'm not entirely sure what you mean 10% as perm is measured in mD. Porosity perhaps? Shale lam's do impede vertical perm - good assumption. As for Kvert vs K90, it's far to hard to characterize it that one will be typically higher than another. Depositional environments can yield many different types of permeability trends for various reasons.

That said, using your channel sand it is possible for ripples to impede vertical perm because of current ripple foresets. Additionally, the overall migration of the point bar could change this. Add to this the size and scale of the channel, you could have multiple incised sands, each with their own character, amalgamated on top of each other. Again it depends heavily on the type of depositional system.

Amalgamation
http://sites.google.com/site/aalliiffaazzeellii/Fluvialsediments3.gif

Meandering depositional system
http://sepmstrata.org/Appalachian/PoundGap/images/039-Fluvial-Point-Bar.jpg

As for natural or induced fracturing. Induced fracturing can be caused from the core barrel in the coring process out at the rig. Natural fracturing can occur for multiple reasons but for the sake of argument, mainly tectonic activity (faults, uplifts etc).

[badatusrnames]

Originally posted by msommers
I'll take a look later as the pictures are being blocked right now.

Kvert/K90, I'm not entirely sure what you mean 10% as perm is measured in mD. Porosity perhaps?


I've divided the two permeability values (mD/mD), to give a percentage. Typically, when you're inputting permeability into a reservoir simulator, you'll specify your vertical permeability as a proportion of your horizontal permeability (in my case, 0.1, or 10% KV/KH).


Originally posted by msommers
As for Kvert vs K90, it's far to hard to characterize it that one will be typically higher than another. Depositional environments can yield many different types of permeability trends for various reasons.

That said, using your channel sand it is possible for ripples to impede vertical perm because of current ripple foresets. Additionally, the overall migration of the point bar could change this. Add to this the size and scale of the channel, you could have multiple incised sands, each with their own character, amalgamated on top of each other. Again it depends heavily on the type of depositional system.



You're starting to exceed my knowledge pretty quickly.

Really don't know much about the depositional system, literature tells me that the formation consists of sandstone regionally interpreted as a primarily fluvial succession that filled incised valleys of the sub-Cretaceous, Paleozoic unconformity.

From logs, over 30 m of gross pay, there are about ten cleaner sands broken up by thin, interbedded shales.

It's been helpful though, thanks!

[msommers]

Originally posted by badatusrnames


I've divided the two permeability values (mD/mD), to give a percentage. Typically, when you're inputting permeability into a reservoir simulator, you'll specify your vertical permeability as a proportion of your horizontal permeability (in my case, 0.1, or 10% KV/KH).

Did not know this, thanks.

Glad to be of help.