API 7102 : 1997

Table of Contents

1 Introduction
1.1 Origin and nature of NORM
1.2 Project objectives and scope
1.3 Report organization
2 Scintillation detector characteristics
2.1 Instrument calibration
2.2 Variability of detector response
2.2.1 Variability between detectors
2.2.2 Environmental effects on detector variability
3 development of correlations
3.1 Theoretical development of the detector correlation
3.2 Laboratory measurements
3.2.1 Radioactive sources
3.2.2 Equipment configurations tested
3.3 Results and analyses
3.3.1 Determination of ft
3.3.2 Determination of K
3.3.3 Development of the correlation for radium concentration
3.3.4 Implementation of the correlation
3.3.5 Correlation for thin scales and gas plant equipment
3.3.6 Correlation for soil
4 Variations in source and detector geometry and
      correlation sensitivities
4.1 Geometries and orientations considered
4.2 Minimum detectable concentrations with a one-inch NaI
      detector
4.3 The use of alternative detectors
4.3.1 Detector configurations
4.3.2 Results
5 Field application of the correlations
5.1 Field measurement data
5.2 Field test of gas plant correlation
5.3 Tests of wall thickness and NORM thickness terms
5.4 Field test of the radium correlation for large equipment
5.5 Field test of the radium correlation for tubing
5.6 Field test of the radium correlation for Yard pipe and
      similar diameter equipment
5.7 Field test of the radium correlation for soils
6 Summary and conclusions
List of Tables
2-1 Comparison of resolutions of the 609 KeV peak measured
      with five different detectors
2-2 Gamma measurements on three tubing samples using six
      different scintillation detectors under identical conditions
3-1 Radium-226 analyses in selected bags of uranium tailings
      used in the laboratory correlation Measurements
3-2 Characteristics of oil field production tubing
3-3 Scintillometer measurements of oil scale in small flat
      plate geometry
3-4 Scintillometer measurements of tailings in small flat
      plate geometry
3-5 Additional scintillometer measurements in small flat
      plate geometry
3-6 Scintillometer measurements of tailings in large flat
      plate geometry
3-7 Scintillometer measurements of tailings in 20 cm pipe
      geometry
3-8 Scintillometer measurements of oil scale in tubing
3-9 Summary of correlation constant values
3-10 Summary of correlation results
3-11 Test pile data for correlation of Gamma levels with
      radium in contaminated soil
3-12 Gamma level data for correlation of Gamma levels with
      radium in contaminated soil
4-1 Results of tapered source analysis
4-2 Comparison of detector configurations
4-3 Comparison of K's of different detectors using 5 cm
      tubing geometry
List of Figures
1-1 Principal components of the Uranium-238 and Thorium-232
      decay chains
2-1 Operating voltage
2-2 Spectra produced by a 1000 pCi/g Ra-226 source, using
      1" NaI detector No.1
2-3 Spectra produced by a 1000 pCi/g Ra-226 source, using
      1" NaI detector No.2
2-4 Spectra produced by a 1000 pCi/g Ra-226 source, using
      1" NaI detector No.3
2-5 Spectra produced by a 1000 pCi/g Ra-226 source, using
      1" NaI detector No.4
2-6 Spectra produced by a 1000 pCi/g Ra-226 source, using
      1" NaI detector No.5
2-7 Voltage plateau curves for the five scintillation
      detectors
2-8 Detector response vs. varied thresholds
3-1 Major factors affecting the measurement of radiations
      from NORM
3-2 Counting configuration for large diameter equipment
      simulation
3-3 Counting configuration for medium diameter equipment
      simulation
3-4 Counting configuration and sample points used to
      measure tubing detector response to well tubing
3-5 Comparison of calculated ft's for tailings, small plate
      geometry
3-6 Comparison of calculated ft's with observed ft's for
      oil scale, small plate geometry
3-7 Comparison of calculated ft's with observed ft's for
      tailings, large plate geometry
3-8 B as a function of equipment diameter
3-9 Comparison of correlation radium concentrations with
      measured concentrations in the laboratory
3-10 Variable "A" as a function of NORM thickness
3-11 Variable E as a function of equipment wall thickness
3-12 Variable E as a function of equipment wall thickness
4-1 Detector response for different detector orientations
4-2 Detector response as a function of distance from surface
4-3 Gradually tapered source
4-4 Abruptly tapered source configuration
4-5 Bulk detection limits for plate and tubing geometries
4-6 Surface detection limits for plate and tubing geometries
4-7 Effect of background intensity on bulk limit of detection
      for 1" NaI detector
5-1 Comparison of predicted and measured NORM surface
      concentrations for gas plant equipment
5-2 Ratio predicted to measured NORM surface concentrations
      for gas plant equipment as a function of wall thickness
5-3 Ratio of predicted to measured radium concentrations
      for thick equipment walls
5-4 Ratio of correlation to measured radium concentrations as
      a function of NORM thickness
5-5 Ratio of correlation to measured radium concentrations for
      new NORM thickness correction
5-6 Comparison of correlation radium concentrations with
      measured concentrations for large equipment
5-7 Comparison of correlation radium concentrations with
      measured concentrations for tubing
5-8 Comparison of correlation radium concentrations with
      measured concentrations for intermediate diameter
      equipment
5-9 Comparison of correlation radium concentrations with
      measures concentrations in soils and pit

Abstract

Capabilities of common field-survey equipment are characterized for measuring NORM in sludges and scales accumulated in oil and gas production equipment.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	American Petroleum Institute
Pages
ISBN