Any Drilling or Production Engineers here?!

[vengie]

I am currently taking Petroleum Engineering tech at SAIT and am taking Drilling 3, however my instructor has no idea what he is talking about...

This will be an odd thread, however I have a few questions I need answered about both casing drilling and under balanced drilling.

If there is anyone here who can answer a few questions, and they are technical, please PM me.

If not I will get in contact with a Drilling company directly.

Thank you

[badatusrnames]

Originally posted by vengie
I am currently taking Petroleum Engineering tech at SAIT and am taking Drilling 3, however my instructor has no idea what he is talking about...

This will be an odd thread, however I have a few questions I need answered about both casing drilling and under balanced drilling.

If there is anyone here who can answer a few questions, and they are technical, please PM me.

If not I will get in contact with a Drilling company directly.

Thank you

PM ExtraSlow, he's a Drilling Engineer.

Also, have you tried the Google??

[vengie]

Originally posted by badatusrnames


PM ExtraSlow, he's a Drilling Engineer.

Also, have you tried the Google??

Thank you, I sent him a PM.

Also google just came up with vague results...


In the meantime, does anyone here have technical experience in both Under balanced and Casing Drilling?!

[dandia89]

just call a drilling company, i'm sure they could give you a pretty generic answer

[vengie]

Originally posted by dandia89
just call a drilling company, i'm sure they could give you a pretty generic answer

Thats what I'm trying to avoid Asad! ahah I want a technical answer to better understand the whole process!

[Impreza]

Why don't you post up what you need to know?

[ExtraSlow]

If you want, you can do it by PM, or you can post here and I'll monitor this thread. There are several otehrs on beyond who know about this stuff.

[dandia89]

post here! i'm very curious too

[vengie]

Peter, I just sent you an e-mail.

For anyone else that is curious my questions were:


Casing Drilling:

The only question is, what would be done to change the bit if it were to wear prematurely, or was out of effective use?

My understanding is casing drilling is used in order to save rig time tripping out drill pipe/ running casing... But I also know once casing is tourqed, disconnecting for trips several times for a bit change would destroy the threads, thus the casing is unusable thereby increasing costs.

If I am wrong with any of that please let me know!

For Under balanced drilling:

1) If the well is being "produced" as you drill, would you still run casing/ complete the well the same way a conventional well would be completed?
2) How would you run casing/ cement an already producing well?
3) Is it formation dependant? Ie, if you're drilling in a consolidated sandstone or limestone or any other soft formations, wouldn't drilling under balanced actually cause sloughing?

I am more curious about Under balanced than anything as I am choosing it as my topic for my term project.

Again any help at all will be greatly appreciated

[SJW]

Originally posted by vengie
Peter, I just sent you an e-mail.

For anyone else that is curious my questions were:


Casing Drilling:

The only question is, what would be done to change the bit if it were to wear prematurely, or was out of effective use?

My understanding is casing drilling is used in order to save rig time tripping out drill pipe/ running casing... But I also know once casing is tourqed, disconnecting for trips several times for a bit change would destroy the threads, thus the casing is unusable thereby increasing costs.

If I am wrong with any of that please let me know!

For Under balanced drilling:

1) If the well is being "produced" as you drill, would you still run casing/ complete the well the same way a conventional well would be completed?
2) How would you run casing/ cement an already producing well?
3) Is it formation dependant? Ie, if you're drilling in a consolidated sandstone or limestone or any other soft formations, wouldn't drilling under balanced actually cause sloughing?

I am more curious about Under balanced than anything as I am choosing it as my topic for my term project.

Again any help at all will be greatly appreciated

Tesco developed some casing drilling. Perhaps you could call their R&D dept. and speak with an engineer there.

[ExtraSlow]

Dang, just sent you an email, but here's the coles.

The short story is that if you are casing drilling, usualy you aren't planning to need more than one bit, or to trip out of the hole for any reason. There are casing connectins (threads) that are more durable, and careful maekup/breakout procedures can help, but it's preferred if your casing is a one-way trip. Tesco is the leader in this technology, and they developed it in Calgary.

The only underbalanced work I've done, we've drilled underbalanced and then increaed our mud weight before runnign casing or cementing. If you don't or can't do that, see belwo:

I'm sure it's possible to run your casing while the well is flowing a little, as long as you are circulating pretty much continuously (using top drive and casing running tool) and you have some method of controlling the flow of gas and mud up the annulus around yoru casing (annular BOP or specialized divertor I'd guess).
For cementing when the well was previously underballanced, you could just set a packer at the top of your producing zone, then open a stage tool and cement normally above that. That part would be easy compared to the hassle of getting the casing into a flowing well.

As for hole stability, Underbalanced drilling is usualy used in hard rock to increase ROP. Reducing mud weight also reduces hole stability in unstable zones, so it's a big risk of getting stuck depending on your formation. You'd typically set intermidiate casing below any unstable zones beofre doing UBD work.

Weatherford and strata do a lot of the underballance work in this part of the world.

[Impreza]

Originally posted by vengie
Peter, I just sent you an e-mail.

For Under balanced drilling:
3) Is it formation dependant? Ie, if you're drilling in a consolidated sandstone or limestone or any other soft formations, wouldn't drilling under balanced actually cause sloughing?

I can't really answer your questions, but when we drill underbalanced in pretty soft sands, we never really have much of an issue with sloughing.

[vengie]

Peter,

Just received your email!

Thank you very much for your reply, definitely makes the whole situation easier to understand!

and Impreza

How under balanced are you drilling?? and as Peter pointed out, are you mudding up to prevent the slough? or...

[SJW]

Originally posted by Impreza


I can't really answer your questions, but when we drill underbalanced in pretty soft sands, we never really have much of an issue with sloughing.

As long as you're cleaning hole it should'nt. Do you run Pressure While Drilling ?

[vengie]

Originally posted by SJW


As long as you're cleaning hole it should'nt. Do you run Pressure While Drilling ?

If you're cleaning the hole at a high enough rate, plus the soft formation, plus being under balance, wouldn't you run the risk of a possible washout, and or formation damage??

Man there is a lot to this!

[SJW]

Originally posted by vengie


If you're cleaning the hole at a high enough rate, plus the soft formation, plus being under balance, wouldn't you run the risk of a possible washout, and or formation damage??

Man there is a lot to this!

Yes drilling is quite dynamic. Any time there is a soft formation you risk borehole washouts. You circulate in one area for a period of time you risk it as well.

If you slide while directional drilling you build up cuttings too. It's why the mud is the most important thing on the rig.

[vengie]

Originally posted by SJW


Yes drilling is quite dynamic. Any time there is a soft formation you risk borehole washouts. You circulate in one area for a period of time you risk it as well.

If you slide while directional drilling you build up cuttings too. It's why the mud is the most important thing on the rig.

This is why I'm interested in becoming a Drilling Engineer. Keeps you thinking.

[SJW]

Originally posted by vengie


This is why I'm interested in becoming a Drilling Engineer. Keeps you thinking.

I actually want to go back to school too but I'm too planted and have a young family.

[Impreza]

Originally posted by SJW

If you slide while directional drilling you build up cuttings too. It's why the mud is the most important thing on the rig.

If only more people realized this!! Mud is such an important tool that is so often overlooked. I've seen guys just throw anything and everything down the hole lol.

[dandia89]

what about mist?