Tom knows his stuff - SLB stuff - I worked with some on some early IC's - they were
thinking about using Bipolar IC's downhole. :-) The shaped charge was a cool concept.
Martin
Tom Miller wrote:
Can you fill me in on how a hole is profiled using a radioactive source?
My wife and her sister are convinced that their father died (eventually)
of radiation poisoning caused by an accident at a well. The story, as
I heard it, was that he (working for Wellex/Halliburton in the 50's) was
on a crew shooting a well. The drill hit a gas pocket and drill, pipe,
and radioactive source were shot into the air. The container holding the
radioactive source ruptured mid-air and covered the crew in a white
powder. The crews' exposure badges were lost by Wellex. The guys on the
crew were transferred to different areas of the country, and all died
young from old age (the girls' father died at 47 fighting kidney, liver,
and heart failure).
I there any possibility that this could have happened? How hot is the
radiation source?
Or have the girls whipped up a conspiracy theory?
Kevin Gallimore
I worked for Schlumberger much later (late 60"s early 70"s) so I suspect
that the sources were less powerful by that time as the sensor technology
had improved considerably by then. The most common radioactive survey when I
worked for them ,measured the density of the formation by bombarding it with
gamma rays from a cobalt 60 source. ( about 1 Curie if I remember
correctly). The amount of radiation reflected back to the tool was measured
and gave a measurement of the bulk density of the formation. If you knew the
type of formation (sandstone or limestone were the only ones of interest as
that is usually the only type you find oil or gas in) then you knew the
density of the pure rock and could calculate the porosity of the formation.
From resistivity surveys. you could tell weather the pore spaces were filled
with water or oil or gas.
Shooting a well is also called perforating. The well is cased with steel
casing which is cemented into the hole from top to bottom. To allow the oil
to flow into the hole, explosive shaped charges are located opposite the
production zone and fired electrically from the surface. These blow holes
about 12 mm in diameter through the pipe & cement and into the formation
about a metre deep.
I don't know if Wellex used some other technology in those days, but they
were looked down on buy the Schlumberger engineers as a "poor cousin".
Shclumberger was the acknowledged leader in the field. They did huge
amounts of research, built all their own equipment in house,and never
patented anything. They believed that they could stay 2 years ahead of their
competitors and didn't give out any information. I had to sign all sorts of
confidentiality agreements when I went to work for them.
It seams kind of unlikely that they would have a radioactive source downhole
while perforating as the sensors were really sensitive to shock. The
Schlumberger sources were about 20 mm in diameter and maybe 100 mm long.
They were a stainless steel tube with a Cobalt wire in them that was the
actual source. I suspect that you could put them in a shotgun and shoot them
at a wall without causing a leak.
On the other hand, I heard rumours that a long time ago,(1950')somebody had
found an earlier type of source on a
lease in northern Alberta. They used to take the source out of the truck and
place it in a roped off area on a corner of the lease. Some cat skinner
found it and used it as a track pin punch and ruptured it. The source
material was a powder in the case and contaminated himself and a big area.
It was all supposed to have been hushed up. I don't know how true it was but
it was one of those "oilpatch myths" that circulated.
Schlumberger crews were chopped and changed and moved all over the country
so the movement of the crew probably didn't have any sinister connotations.
--
Martin Eastburn
@ home at Lion's Lair with our computer lionslair at consolidated dot net
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder
----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----