With winter headed our way, a lot of us are starting to think about maintenance and upgrades during our slow season.
winter headed our way, a lot of us – especially the guys up North who usually
shut down – are starting to think about maintenance and upgrades during our
slow season. Of course, the drillers in the South run year ‘round, so they get
to work on the rig whenever time and jobs permit.
Sometimes maintenance can be put off until an opportune time, and sometimes it
can’t. There is nothing worse than being broke-down on location with the
customer standing there, wondering what’s going on. I know a driller who
recently has taken on a lot more deep work. He knows he needs to string up to
three lines on his blocks, instead of the two-line string up he’s used for
years, but he figures he’ll get “one more job” out of the way before he does
it. I expect a call from him any day, complaining that his drawworks are gutted
from continuously running too heavy. That is an example of maintenance that
shouldn’t be put off.
One item that slips by a lot of drillers is the condition of the swabs and
liners in the mud pump. The very slow, gradual decrease in efficiency is easy
to miss, but there is an easy way to keep track of the condition of your pump.
On my rigs, I have a fairly small orifice in the eductor of my mixing hopper.
When I start a job, I’m mixing mud with clear water straight out of the water
truck, so all the conditions are the same each time. Right after a pump
rebuild, I note the pressure on the gauge at a known pump speed (usually idle).
Then on each job, I look at the gauge when I start the job and mix mud. When
the swabs and/or liner start to wear out significantly, the gauge pressure
slowly goes down, and I know it’s time to rebuild the pump. This sure beats
waiting until I’m deep in the hole, and the pump won’t prime or pick up worth a
hoot, and I can’t circulate the hole properly. Knowing ahead of time helps in
Another item that can easily be overlooked is chain drives. A lot of smaller
rigs have chain drive to the mud pump. There generally are two types of drives.
On some rigs, the clutch is on the transfer case, and the chain only runs when
the pump is in gear. On the other, the clutch is on the pump shaft, and the
chain runs continuously. Why the engineers design them that way is beyond me –
they eat chains and sprockets at five times the rate of the
A common maintenance issue on chain drives is when the chain wears enough to
get loose and start jumping teeth on the sprockets. When a chain starts jumping
teeth on the sprockets, you’ve only got a few minutes to fix it before you
start tearing things up pretty good. A lot of drillers just take a link out of
the chain and add a half-link. This is a stop-gap fix at best. When the chain
stretches enough to start jumping the teeth on the sprockets, it usually is
worn out and needs to be completely replaced. By taking a link out of a
stretched chain, you are running a mismatched chain and sprocket, and wearing
out the sprockets long before their time. Replacing the sprocket on the clutch
end is a major pain and expense. Just replace the whole chain, and you’ll get a
lot more life out of your driveline components.
A working chain oiler also is a very good idea. I run synthetic oil in my
trucks, so when I change oil, I save it to run in drip oilers on my chain
drives. Another good lube comes in a spray can, and is sprayed on while the
chain is still. The solvent helps the lubricant penetrate the chain, and then
evaporates, leaving a fairly thick lube right where it’s
Another place that often is overlooked, but has the potential to save money, is
in the maintenance of your drill lines. On water well rigs, a lot of drillers
just run their drill lines until they wear out and then replace the whole
thing. If you look at your drill lines when they are worn out, you will find
that the wear points usually are right at the point that you pick up the slips
and the line takes the load. If you can move that wear point periodically, you
can significantly increase your line life.
The easiest way to do this: When you get a new line, buy a few extra feet and
spool it up. Then, as time goes on, periodically cut a couple feet off the line
and re-spool it. This will move the wear point from the pick-up point and will
greatly increase the line life. Also, after a couple of cuts, un-spool the line
and turn it end-for-end. This way you can maximize your line life. On big rigs
in the oilfield, they keep a ton-mile book that calculates exactly how much
wear is on a line, and when to cut and slip it, and by how much.Hope this
helps. Just because the rig is running today doesn’t mean it will be running tomorrow,
unless we take care of it.
The World According to Wayne: Assorted Rig Maintenance Tips
December 1, 2008