The "Official" One Week Til Christmas Breakroom
DTR Mom
Joined: Dec 2005
Posts: 347
Likes: 0
From: hills of cali forn ya
but pretty good for a generation that figured it out; heck, 35 years after the song?! pretty smart young folks now adays....
Hey T raddy, miss you, hope your household can survive the 'virus'....
new rules or a big ol' lock for Christmas? miss my desktop.....sniff
all angels sent out for those travelling, devils for ones staying home...muh hahha
got son a digital picture frame, loaded that thing with about 700 specially selected pictures and videos.....glad I am done, let's say..
Bark, stop vacuuming up your 'guests' eheheh
Hey T raddy, miss you, hope your household can survive the 'virus'....
new rules or a big ol' lock for Christmas? miss my desktop.....sniff
all angels sent out for those travelling, devils for ones staying home...muh hahha
got son a digital picture frame, loaded that thing with about 700 specially selected pictures and videos.....glad I am done, let's say..
Bark, stop vacuuming up your 'guests' eheheh
DTR Mom
Joined: Dec 2005
Posts: 347
Likes: 0
From: hills of cali forn ya
I wish I was as fine, as those who work the pipeline!
Joined: Dec 2008
Posts: 1,639
Likes: 0
From: Wyoming
So what stops the bit from eventually twisting itself off and breaking? In my limited experience with metals, you can only twist something back and forth just so many times before it breaks. If you stop the bit, which I imagine you have to do to add another section, doesn't it UNtwist until all the reactive torque is released? Then when you start it again, it twists up again. All I can picture is a twisted off driveshaft!
Anyway, they do twist off though, but you generally have to get the bit stuck and make a series of errors before that happens. And yes, most of the reactive torque does 'come' out. There is still torque in the string, but only that which the friction of the hole will hold. When you start rotating again, the string torques up, as when lining up the bit to slide you add wraps of pipe to hold the bit where you want to (one of many forces at play that you manipulate to steer the bit). Before you slide, you have to work the pipe up and down to get it all out so you know you are starting at 0 wraps.
Here is the hard part, at 12000 feet, the reactive torque you put in the drill string at surface only goes down about 500'. You have to work it down the string by raising and lowering, if you get to much, and it unwinds - you can back out of a tool joint somewhere in the middle. No fun...
There is no G. There is no G. Repeat after me, THERE IS NO G!
Joined: Jan 2006
Posts: 1,688
Likes: 4
From: Texas
Administrator
Joined: Jan 2004
Posts: 2,331
Likes: 2
From: Kalamazoo, Michigan
Hey Claude! Good to see ya 'round!
Well, yes and no. The drill pipe is produced to very specific tolerances and designs. It is regularly tested and certified. You do not want a drill string to break off right above the production zone, especially if there is pressure n the zone. It will come up the inside of the pipe at you, which limits your well control options significantly.
Anyway, they do twist off though, but you generally have to get the bit stuck and make a series of errors before that happens. And yes, most of the reactive torque does 'come' out. There is still torque in the string, but only that which the friction of the hole will hold. When you start rotating again, the string torques up, as when lining up the bit to slide you add wraps of pipe to hold the bit where you want to (one of many forces at play that you manipulate to steer the bit). Before you slide, you have to work the pipe up and down to get it all out so you know you are starting at 0 wraps.
Here is the hard part, at 12000 feet, the reactive torque you put in the drill string at surface only goes down about 500'. You have to work it down the string by raising and lowering, if you get to much, and it unwinds - you can back out of a tool joint somewhere in the middle. No fun...
Anyway, they do twist off though, but you generally have to get the bit stuck and make a series of errors before that happens. And yes, most of the reactive torque does 'come' out. There is still torque in the string, but only that which the friction of the hole will hold. When you start rotating again, the string torques up, as when lining up the bit to slide you add wraps of pipe to hold the bit where you want to (one of many forces at play that you manipulate to steer the bit). Before you slide, you have to work the pipe up and down to get it all out so you know you are starting at 0 wraps.
Here is the hard part, at 12000 feet, the reactive torque you put in the drill string at surface only goes down about 500'. You have to work it down the string by raising and lowering, if you get to much, and it unwinds - you can back out of a tool joint somewhere in the middle. No fun...