[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: TENORM in the State of WV
Gert,
NORM contamination in oil production consists primarily of Ra-226- and
Ra-228-bearing produced waters and radium-bearing precipitates that
accumulate in scale and sludges derived from those waters. Produced waters
may contain up to a few thousand pCi/L of Ra-226. Ra-228 activity
concentrations are much less commonly measured, but often are equal to the
Ra-226 activities. The solids may contain up to several hundred thousand
pCi/g, but a few hundred to a few thousand pCi/g is most common. Barite is
the primary mineral carrier for radium, although several other
radium-bearing minerals are known in scale and sludges. In general, the
higher the TDS concentration of the produced water, the greater the
concentration of radium in solution. Radium is more soluble under the
high-chloride, reducing conditions typical of produced waters, probably
because of chloride complexing with radium and the increased solubility of
barite. Uranium and thorium are very insoluble in produced waters and
activities are <<1 pCi/L, thus radium is in gross disequilibrium with its
two parents.
In gas production (which is the dominant hydrocarbon production in West
Virginia), Pb-210 plateout from the decay of radon entrained in the natural
gas is the predominant form of NORM. The plateout favors certain parts of
gas processing equipment, valves, elbows, filters, etc., basically any part
of the production mechanism where turbulence occurs and contact of the gas
stream with the equipment surfaces is increased. Evidence suggests that
"wet" gas production has higher radon content because of the similarities in
gas properties between radon and some of the heavier gas fractions. In the
late 1960s and early 1970s, concern over radon in natural gas lead to
surveys of the radon content of natural gas at end user points in the U.S.
and to look at indoor radon levels and doses where natural gas was being
used. Radon activities in indoor air and resultant doses due to natural gas
use were generally found to be negligible (Barton and others, 1973).
The American Petroleum Institute's 1989 survey of NORM in U.S. oil and gas
production did not include any operations from West Virginia because of a
lack of operator participation, which was voluntary. We have anecdotal
reports from oil company geologists that suggest that gas production
equipment in West Virginia can have high radioactivity. Oil production in
the Appalachian Basin has resulted locally in substantial NORM contamination
which has been thoroughly documented in the Martha and Big Sinking Creek
fields in eastern Kentucky. Other fields have been surveyed by the State of
Kentucky and elevated levels have been found in some areas. We surveyed oil
and gas production in some fields in northeastern Tennesee and found no NORM
associated with gas well heads and only modest NORM in oil production.
Because the uniformly high TDS and chloride concentrations in most
Appalachian Basin produced waters from western New York to southeastern
Kentucky, we suspect that NORM may be widespread, but experience suggests
that its occurrence will be spotty and dependent on local oil and gas
production conditions.
Based on its review of NORM in oil and gas production, the USEPA (1997,
unpublished) predicted that about 30 percent of U.S. operations will have
NORM levels of concern.
The NORM content of cuttings derived from drilling operations is generally
very minor, a few pCi/g of uranium and thorium combined in the vast majority
of rocks encountered in oil and gas basins. Occasionally, intervals of
black shale may be encountered where U concentrations may be substantially
increased (to 100 ppm- about 30 pCi/g- in some cases).
Barite used in drilling muds has very low activities.
Jim Otton
U.S. Geological Survey
Energy Program
-----Original Message-----
From: Franz Schoenhofer [mailto:franz.schoenhofer@chello.at]
Sent: Monday, January 01, 1996 6:46 PM
To: norm-tenorm@yahoogroups.com
Cc: 'Dwaine Brown'
Subject: AW: [norm-tenorm] TENORM in the State of WV
-----Ursprüngliche Nachricht-----
Von: Jonkers, Gert G SIC-ASA/3 [mailto:Gert.G.Jonkers@opc.shell.com]
Gesendet: Freitag, 27. Dezember 2002 14:12
An: 'norm-tenorm@yahoogroups.com'
Cc: 'Dwaine Brown'
Betreff: RE: [norm-tenorm] TENORM in the State of WV
Dwaine,
Thanks for your reaction. From your answer I understand, that the NORM issue
in this case is mainly a consequence of displacing natural rocks/minerals
(which will contain Naturally Occurring Radionuclides at natural levels
typical for the mineral of concern) from somewhere deep down in the
(drilled) hole into the mud pit. I wonder if here really is a concentration
mechanism 'at work'.
This issue keeps on puzzling me. Would be grateful, if you can elaborate
somewhat wrt the follwoing queries:
Did you ever check on what kind of NOR's (identification) are involved at
what concentration levels (quantification).
Did you also analyze for U-238 or Th-232, in what equilibrium with Ra-226
and Ra-228 respectively?
Did you ever (have) measure(d) the activity concentrations (which NOR's were
identified and could be quantified?) in drilling fluids, from which all
particulate material was removed?
What kind of drilling fluid (base material) did you use in your operations?
(If baryte, what/who was the source/supplier of this material?).
Kind regards,
Gert
-----------------------------------------------
Gert,
NORM-problems in oil and gas drilling is simply associated with the scales
deposited on the drilling equipment. Scales containing high amounts or
Radium tend to be deposited on the inner side of tubes, especially since you
sure know water is usually injected into wells to enhance the output of oil
and the change of ion-activities, pH etc. forces either barium sulphate or
calcium sulphate to precipitate together with radium. These questions have
been even addressed in European Union publications, the phenomenon is very
well known in the Norvegian and British oil industry and it is not so long
ago, when an American company was sued for millions (or rather billions) of
dollars, because they cleaned their equipment on a private estate and left
all the scales there. May I express my surprise, that this would not be
known to Shell?????
For more information - if necessary, please contact me privately.
Best regards
Franz
Moderated by: Phil Egidi
pegidi@tenorm.com
http://www.tenorm.com
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
************************************************************************
You are currently subscribed to the Radsafe mailing list. To unsubscribe,
send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
radsafe" (no quote marks) in the body of the e-mail, with no subject line.
You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/