Drilling
rigs historically have been built to last longer than almost any commercial
product, except maybe fine musical instruments. There are some good reasons for
this. The technology changes very slowly, sometimes taking decades for
improvements to be accepted in the market. Drillers tend to be very
traditional, and it usually takes until the next generation for changes to be
well-received.
Think of the transition from cable-tool rigs to rotary rigs. The technology has
been in use for hundreds of years, but, in the last 100 years, they became
common. Many companies built cable-tool rigs, and they still are being built –
mostly because there still are some areas where cable tool is the best, or it’s
sometimes the only way to drill a successful well. It is not uncommon to see
cable-tool rigs mounted on 50-year-old trucks that still
run.
Table-drive rotary rigs have been around at least for 100 years in the
oilfield. It took World War II to bring small, portable, truck-mounted rigs
into common use. The Army needed to provide water for the troops, quickly, in
any part of the world. The George E. Failing company rose to the challenge and
built portable rigs for this purpose. Some of them still are around, and the
designs and technology still are being produced. Soon other companies joined
the market, and the race was on.
With the advent of modern hydraulic systems, the top-head-drive rigs came onto
the market. At first, they were underpowered and unreliable, and the older
drillers didn’t like them, probably because they didn’t understand them. But
they hung on, and made improvements as hydraulic systems became more
sophisticated. In a rare reversal, the water well rig manufacturers led the
oilfield in this technology. It is just in the last few years that powerful
enough top-heads have been built for the big rigs.
All this history leads me to the observation that rigs usually outlast the
trucks they are mounted on by several times. I’ve seen well-maintained rigs go
through five trucks in their lifetime. This leads to the re-mount decision.
There also are other reasons; sometimes road or field conditions or DOT
regulations change enough to make the truck obsolete, or sometimes a driller
may decide to sell his rig, and he knows that a more modern truck will increase
its value more than the cost of the re-mount.
When selecting a new truck to mount your rig on, there are several
considerations to take into account. Since the paying part of the job is in the
field, a truck that will do the job is very important. It must be strong enough
to get the rig from the end of the road to the stake-in-the-ground. This almost
always requires a truck that is much stronger than one that just drives down
the road. In fact, the military de-rates their trucks by half for off-road use.
Obviously, if you spent 300 days a year on location, and only 10 days a year on
the road, an 80-mph highway truck is not the best choice. Winching and repair
cost soon will eat up any savings. A good choice might be a truck model that
doesn’t change too often. There is nothing that makes a rig look old quicker
than a dated truck. A good ol’ standby might be a crane carrier; they are very
strong, and they look just about like they did 50 years
ago.
Next is engine and transmission selection. It is important to have an engine
that you can get parts for. Is there a good dealer network in the area where
the rig is going to be used? For rigs going overseas, this is very important.
Some engines are common in certain area, and some aren’t; it pays to do a
little homework. In some areas, it is difficult to get parts for anything, so
reliability becomes more important. Here in the States and for shipment to
Central and South America, U.S. surplus military trucks can be
a good choice. They are strong, almost indestructible, go anywhere, and parts are
available if you know where to look. Careful attention to the engine
manufacturer is important, as there are trucks available for which you can’t
get parts. In Europe and Africa, a lot of rigs
are mounted on surplus French army trucks. They really are good trucks, and
having come from the French army, they usually have seen very little
use.
Fuel can be a consideration, too. Diesels usually are the most reliable, but
gasoline engines can work too, if the price is right. There also are some
propane-powered rigs, and I’ve seen a lot of trailer-mounted rigs in the
oilfield that ran off wellhead gas. When the rig was spotted, they hooked it up
to the nearest wellhead, and fuel was free. Just a thought: With a dual fuel
system, this would work with a truck-mounted rig.
These are just a few of my thoughts on selecting a truck to remount your rig.
Now all you’ve got to do is git-er-done.
My wife recently figured out how to get out of a speeding ticket. The cop asked
her why she was going so fast, and she told him, “Sonny, at my age, I wanted to
get there before I forgot where I was going!” At 15 mph over the limit, she
just got a warning.
ND
The World According to Wayne: Considerations When Remounting a Drilling Rig
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