KPT's Earth thread

Well you see Ben... When your at the bar and you've lathered yourself in bait..

... I'm not the biggest fan of fried anything

 

You're definitely not american

 

4 minutes aint bad for this early in the morning

lol nope, definitely not

 

Yours was more detailed and informative

No hard feelings, Beth

 

Ha! I was about to say, "it's cool Keith, your answer was more complete."

Man. Now I want a fried pie.

 

Probably the cones off a tricone bit. If they try to use the bit too long, push it until it's as dull as it can possibly be, it falls apart, and they have to retrieve the parts from the wellbore.

3 times through I've seen fishing trips for the entire bottom hole assembly- that's the bit, motors, steering tools, MWD tools (measurement while drilling, used to tell you where the drill is), etc. Pricey there.

 

How long would it take to fish out all of that stuff??

 

I've seen them fish for 10 days and not recover the equipment. All that bottom hole assembly stuff is supposed to be screwed together in 1 piece, the hard part is grabbing it and keeping hold of it until you get it 2 or 3 miles back to the surface.

If they can't recover it they can sidetrack the well, which means they find a point in the original wellbore where they can start drilling in a different direction and go around the equipment. But leaving all that equipment in the well is expensive, so they try not to do that.

Edit: this time Keith was faster!

 

What's +'s and -'s between the tri-cone and PDC's?

 

I like the tri-cone

The PDC looks like a big vicious version of some of our glass drilling bits here at work.

 

I'm not really sure what is more common, I've seen both used. I'd guess tricones are more common though, especially in the lateral, which is either moderately consolidated sand or sandy dolomite. We even used a button bit once.

Here's a button bit, for comparison:


When I was in Oklahoma it was tricone through the vertical as much as possible (there are a couple limestone formations they often had to switch to a PDC though) and then PDC for the lateral.

 

So, I'm assuming the tri-cone, pdc and button bits are used for getting through actual rock only, correct? Do you use just a big auger bit initially until you get to the rock?

 

They are built to handle different types of rock. I'm far from an expert but tricones are for softer rocks like unconsolidated sandstones or soft limestones and shales. Harder rocks like a hard limestone or hard shale require a PDC.

They just use whatever bit the top bedrock layer will require to get through the soil, I think? I've only once been on site at the very start of the well, onsite geology isn't usually needed until later.

 

Exactly! The drilling fluid, or mud, is pumped back up to the surface, carrying the drill cuttings with it. That's where I come in. I take samples of the drill cuttings, clean the drilling mud off of it, and analyze the rocks That's about half of the substance of my job, and about 75% of my time.

 

That's about all I know. I don't get anywhere near the top of the wellbore. It's underneath the rig and there's a lot of equipment and moving parts there; I'd probably just hurt myself Also it has nothing to do with my job, so best to stay out of the way. I collect cuttings after they go across the shakers, maybe go talk to the driller occasionally, and otherwise I stay off the rig.

 

Fellow consulting geologist here! Cool thread, but I'm a hardrock kind of a guy... and preferably underground!