lionslair at consolidated dot net wrote:
Ken Cutt wrote:

lionslair at consolidated dot net wrote:

Ken Cutt wrote:

Tom Miller wrote:

wrote in message
...

Oil rigs seem to be capable of drilling holes inches in diameter
and thousands of feet deep. They can keep these holes amazingly
straight or deliberately curve them.

How do they do this and what does the drill head look like?

Jim






I worked in the oil patch in Alberta in the 1960's & 70's. At that
time
directional drilling was expensive and uncertain. Straight drilling
was done
by using very heavy "drill collars" at the bottom of the drill
string. The
bits were usually three steel cones with carbide buttons on
them.The cones
were mounted on bearings with the base of the cones just off the
centre line
of the drill and the point of the cone facing outward. Drilling mud
was
pumped down the centre of the drill string,and the entire string was
rotated. The buttons on the bit broke up the rock and the chips
were flushed
up the annulus between the hole and the drill string. This mud was
allowed
to run over a "shale shaker" which separated any large chips. The
mud was
recirculated continuously. After a while the bit wear and drilling
would
slow. This meant that the entire drill string had to be pulled out,
unscrewed into 90 ft sections and stacked on end in derrick. In
those days
the deepest holes in Alberta were about 17,00 ft. It could take
over 24
hours of heavy ,dirty work to replace a bit so bit quality was
paramount.
Directional drilling has matured enormously since then so I'm not
familiar
with present procedures


I also worked on rigs in Alberta in the 70's . Did lots of deep hole
directional drilling . Certainly in those days it was anything but
hi-tech . Three kinds of bits . Diamond used only when pulling core
samples . Toothed bits when the substrata was soft rock and button
bits when the rock was harder . When passing through strata the
wrong style bit pretty much stops progress so you have to pull the
entire pipe out and switch them . I never got as deep as 17,000 but
13,000 took about 17 hours round trip . Dangerous time . Every time
the pipe is pulled a long metal rod is dropped down the center of
the drill stem . Inside is a small compass and a point the punctures
it to show the compass heading at the bottom of the hole . If
drilling is going smoothly and the pipe is not pulled often the
rod/compass is dropped down connected to a sand line after it hits
bottom it is winched back up before drilling can proceed . If the
bit has wandered to the right heading heavy thick pipes (collars)
are added right behind the bit to hold it at the desired course .
these do not flex so bore straight . In addition every so often a
specialty outfit is brought in with a contained compass and a camera
. Pictures are taken showing the heading at carefully monitored
distances . In addition every piece of drill stem in measured before
it is added to the string . With the compass shots and the exact
lengths they know very accurately where the bit is at any given
depth . It is also sent to the Gov . I know there was lots of talk
in the real old days about slant drilling but by the time I got on a
rig it was pretty much over , at least in the corner of the world I
worked . I had friends that worked in Indonesia and China , same
there they told me . I never saw a gun or heard of anyone shooting
at anyone either . All I worked were exploratory holes so what was
found was of great interest to the competition and yes there were
spies to watch and film . That said if oil was found everyone told
everyone they knew . I doubt there was any need to shoot at anyone
to protect what would be common knowledge . Hey maybe not ideal but
try stop a batch of 20 year old kids when they know something ;-) .
90 foot sections of pipe flex at least 10 feet when racking them .
So you worked on a triple , me too . There were at least four quads
in Alberta working when I was there so 120 pulls . In the south
hundreds of singles 30 foot pulls and doubles 60 foot pulls . I
never worked any small rigs but guys told me they would go on long
change and have to phone the office to find the new location . Those
rigs moved weekly . Where the big deep hole ones sat in one spot for
6 to 8 months .
Ken Cutt



Nice note Ken -

I knew a fellow scientist at SLB (another lifetime and a better brain
I tell you!)
he was working on and broke it - how to data log with tools in real
time while
drilling ! - Normally a bit is extracted and then the tool set is
dropped down-hole.
This took time and time is money! - Besides - think of having an
expensive crew there
during a extract and drop and pull - or while you drill - the
convince won. Money
was not considered - just tell me today if I have half a change of
oil or if
that pinch out sand group was ever touched... Real time is great for
joy stick control
(almost :-) ) I know how he got by the signal - one "wire" is the
drill stem/pipe system...

Martin

I think the idea of real time would be a huge hit . Only one snag .
Getting the Gov to accept the results . No doubt they would after
dragging the inventor through endless expensive tests . I great idea
that should be in use now . The trick should be how to avoid abrasion
on the wire from the high pressure mud going down the pipe . Not sure
about now but I seem to remember at the pump the pressure was 1800PSI
, add to that half a lb. or so for every foot of depth . Gets real
high on deep holes . If you use the stem itself how do you maintain
contact when each joint is doped ? No doubt there are solutions but
not easy ones .
Ken Cutt

Don't get it right there Ken - there isn't a wire.
The 'wire' is the drill stem and pipe to the surface.
The other wire was the tough one - oh just use Earth - e.g. ground it.

On the top naturally there is a connection - a sliding brush.

The Gov doesn't have to accept squat. - The customer base does.

For a patent - piece of cake. There are sites and wells that are logged
as standards all the time. In fact, test wells are drilled on site at the
research site. Just log well xyz and drill one next to xyz and compare
results.
But for patents you don't need this stuff - just the setup that is
unique...

Naturally this logging isn't all forms of logging - some of those are
really exotic.

Martin

I did think the pipe might be a source but every joint is doped and a
reliable connection will be tricky . Holes drilled under Gov leases have
to meet Gov specs . Not that the accuracy would not be there but getting
a Gov to see it , well you know . Luck though it is a good idea
Ken Cutt