Patent ID: 11914084
Assignee: FIELD WATER TESTING, LLC
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 17:
18. A method for determining whether oil waste at a field testing site selected from an oil transport vehicle, a water treatment facility, or a waste treatment facility is exempt from naturally occurring radioactive material (NORM) waste regulations applicable for a selected region, the method comprising:
determining a percentage of oil waste solids for a sample of the oil waste;
determining a disintegration count per unit time for the sample;
determining a mass value for the oil waste solids using a first nonlinear transfer function based on an oil waste mass calibration model expressible as M=b2(POWS)2+b1(POWS) where:
output M is a mass (in grams) of the oil waste solids;
b2 and b1 are percentage to mass (P2M) calibration factors for a combination of oil waste solids; and
POWS is the percentage of oil waste solids determined by selecting a graduated marking on the BS&W tube nearest to a top level of the oil waste solids;

determining a maximum radioactivity level using a second nonlinear transfer function based on a radioactivity level calibration model expressible as R=c2(CPM)2+c1(CPM) where:
output R is a radioactivity level in picoCuries;
c2 and c1 are radioactive level (RL) calibration factors for a selected type of radioactive waste solids; and
CPM is a detection count rate in counts per minute;

determining a normalized maximum radioactivity level per mass unit; and
outputting at the field testing site a waste status that indicates that the oil waste is exempt from NORM regulations applicable for the selected region in response to determining that the normalized maximum radioactivity level per mass unit R/M falls below an applicable NORM exemption level for the selected region.