Radionuclide Fate in Naturally Occurring Radioactive Materials (NORM) in the Oil and Gas Industry A thesis submitted to the University of Manchester for the degree of Doctor of Philosophy in the Faculty of Science and Engineering 2019 Faraaz Ahmad School of Earth and Environmental Sciences 1 Table of Contents List of Figures…………………………….……………………………………………………………………………………….7 List of Tables…..……………………………..…………………………………………………………………………………15 List of Abbreviations ............................................................................................................. 17 Thesis Abstract ...................................................................................................................... 20 Declaration ............................................................................................................................ 22 Copyright statement ............................................................................................................. 22 Acknowledgements ............................................................................................................... 23 About The Author .................................................................................................................. 25 CHAPTER 1: Introduction…………………………………………..……………………….26 1.0 Project Introduction ................................................................................................... 26 1.1 Aims and objectives ............................................................................................... 31 1.1.1 Outline ............................................................................................................ 32 1.2 Thesis structure ...................................................................................................... 34 1.3 Paper status and author contributions .................................................................. 36 CHAPTER 2: Literature Review…………………………………………..………………………………..38 2.0 Literature Review ....................................................................................................... 38 2.1 Natural uranium - 238 and thorium - 232 decay Series ......................................... 38 2.2 Produced Water – Liquid waste stream ................................................................. 42 2.2.1 Characteristics ................................................................................................ 42 2.2.2 Chemical incompatibility of produced waters ............................................... 48 2.2.3 Mineral solubility……………………………………………………………………………………… 49 2.2.4 Degree of saturation………………………………………………………………………………… 51 2.3 Reservoir processes and scale formation – Solid waste stream ............................ 52 2.3.1 Pipe scale formation ...................................................................................... 52 2.3.2 Reservoir processes and sulphate scales ....................................................... 53 2.3.3 Radionuclide uptake into sulphate scales ...................................................... 56 2.3.4 Calcium carbonate scales ............................................................................... 59 2.3.5 Radionuclide uptake into calcium-containing scales ..................................... 60 2.3.6 Black dust deposits......................................................................................... 61 2.3.7 Radionuclide uptake into black dust deposits ............................................... 62 2.3.8 Sludges ........................................................................................................... 64 2.3.9 Radionuclide uptake into sludges .................................................................. 64 2 2.3.9.1 Scale Prevention ...................................................................................... 66 2.4 Operational discharge of effluent waters to surface waters and NORM formation ............................................................................................................................... 67 2.4.1 Offshore discharges ....................................................................................... 67 2.4.2 NORM formation during operational discharge ............................................ 68 2.4.3 Environmental characteristics ....................................................................... 70 2.5 Radioactivity of NORM ........................................................................................... 73 2.5.1 Solid waste stream – Pipe scale and Sludge .................................................. 73 2.5.2 Liquid waste stream – Produced water ......................................................... 77 2.6 Influence of natural processes and microorganisms on barium and radium remobilisation .. …………………………………………………………………………………………………………………78 2.6.1 Sulphate-reducing bacteria and their effect on barite .................................. 79 2.7 Environmental Implications and Exposure Assessment ........................................ 82 CHAPTER 3: Methodology…………………………………..…………………………………………………89 3.0 Research Methods ..................................................................................................... 89 3.0.1 Safety ................................................................................................................. 89 3.1. Sample collection ................................................................................................... 90 3.1.1 Marine Sediment................................................................................................ 90 3.2 Precipitation Experiment (BaxSrySO4 - Inactive) ..................................................... 91 3.2.1 Seawater and Produced Water Synthesis ...................................................... 91 3.2.2 Precipitation Procedure ................................................................................. 93 3.3 Radium uptake experiment ................................................................................... 94 3.4 Precipitation Experiment (BaxSryRazSO4 – Active) .................................................. 95 3.4.1 Adjusted Brine Composition .......................................................................... 96 3.4.2 Precipitation Procedure ................................................................................. 96 3.5 Sediment Microcosm Experiment .......................................................................... 98 3.6 NORM Sample Characterisation .......................................................................... 102 3.7 Solution and Geochemical analysis ...................................................................... 103 3.7.1 Inductively-coupled Plasma Atomic Emission Spectroscopy (ICP-AES) ....... 103 3.7.2 Ion Chromatography .................................................................................... 106 3.7.3 pH and Eh ..................................................................................................... 108 3.7.4 UV-Vis Spectrophotometry .......................................................................... 108 3.7.5 Liquid Scintillation Counting (LSC) ............................................................... 113 3.7.6 PHREEQC Modelling ..................................................................................... 116 3 3.8 Chemical Extractions ............................................................................................ 117 3.8.1 Heavy Liquid Extraction................................................................................ 117 3.8.2 Sequential Extraction ................................................................................... 118 3.8.3 Barite Dissolution ......................................................................................... 120 3.9 Solid Phase Characterisation ................................................................................ 120 3.9.1 Environmental Scanning Electron Microscopy (ESEM) – Energy Dispersive X- Ray Analysis (EDX) ........................................................................................................ 120 3.9.2 Powder X-Ray Diffraction (XRD) ................................................................... 123 3.9.3 Fourier Transform Infra-red Spectroscopy (FTIR) ........................................ 126 3.9.4 Raman Spectroscopy .................................................................................... 129 3.9.5 BET Surface Area Analysis ............................................................................ 130 3.9.6 X-Ray Absorption Spectroscopy (XAS) ......................................................... 131 3.9.7 X-Ray Fluorescence (XRF) ............................................................................. 134 3.9.8 Gamma Spectroscopy .................................................................................. 136 3.9.9 Autoradiography .......................................................................................... 139 4.0 Microbial Community Analysis – DNA Sequencing .............................................. 142 CHAPTER 4: Fate of Radium on Discharge of Oil Produced Water to the Marine Environment…………………………………..…………………………………………………………145 4.1 Abstract………………… ……………………………………………..…………………………………………………..146 4.2 Introduction…………………………………..………………………………………………………………………….147 4.3 Materials and Methods………………………………………………………………..……………………….…..152 4.3.1 The study area and experimental method…………………………………….…………….152 4.3.1.1 Marine Sediment……………………………………….…………………………………………..152