Radiation Safety in Well Logging

Specific Safety Guide

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• Publisher: International Atomic Energy Agency
• Year: 2020
• ISBN:
  9789201056221
• Topic: Tecnología e ingeniería
• Subtopic: Recursos energéticos

This Safety Guide provides recommendations on the use of radioactive sources and radiation generators in well logging, including in the manufacture, calibration and maintenance of well logging tools. It provides recommendations on radiation protection and safety for the storage, use and transport of such radiation sources. The guidance in this publication is aimed primarily at operating organizations that are authorized to undertake well logging with radiation sources, as well as their employees and radiation protection officers. The guidance will also be of interest to regulatory bodies, and to designers, manufacturers, suppliers, and maintenance and servicing organizations of well logging equipment that contains radiation sources.

1. INTRODUCTION

Background

1.1. As stated in IAEA Safety Standards Series No. SF-1, Fundamental Safety Principles [1]: “The fundamental safety objective is to protect people and the environment from harmful effects of ionizing radiation.” Paragraph 2.1 of SF-1 [1] states:

“This fundamental safety objective of protecting people — individually and collectively — and the environment has to be achieved without unduly limiting the operation of facilities or the conduct of activities that give rise to radiation risks.”

1.2. Paragraph 2.2 of SF-1 [1] states:

“The fundamental safety objective applies for all facilities and activities, and for all stages over the lifetime of a facility or radiation source, including planning, siting, design, manufacturing, construction, commissioning and operation, as well as decommissioning and closure. This includes the associated transport of radioactive material and management of radioactive waste.”

1.3. Mining, ground engineering and water industries and oil and gas exploration and production (conventional and unconventional (e.g. fracking)) make extensive use of radioactive sources, and in some cases radiation generators, for characterizing and evaluating geological formations and borehole and well constructions. The term ‘well logging’ is used in this Safety Guide to include all such practices.

1.4. Well logging work can be performed with a device (often referred to as a ‘logging tool’) containing one or more sealed radioactive gamma and/or neutron sources or a neutron generator. The location for well logging work will normally be at the premises of a client company (e.g. at a mine, or at an offshore oil and gas exploration platform). There are many thousands of radioactive sources and radiation generators used in well logging around the world [2].

1.5. IAEA Safety Standards Series No. RS-G-1.9, Categorization of Radioactive Sources [3] provides a relative ranking of radioactive sources in terms of their potential to cause severe deterministic effects (i.e. how ‘dangerous’ they could be if misused). The categorization is composed of five categories, with Category 1, 2 and 3 sources being the most hazardous. Well logging sources generally fall into Categories 3 and 4; however, the aggregation of sources at a particular well logging site might fall into Category 2.

1.6. This Safety Guide is one of a number of Safety Guides on topics related to safety in industrial uses of ionizing radiation, for example radiation generators and sealed sources, industrial radiography, industrial irradiators and nuclear gauges (see Refs [4–7]).

1.7. Unless otherwise stated, terms are used with the meanings ascribed to them in the IAEA Safety Glossary [8].

1.8. It is assumed in this Safety Guide that an effective governmental, legal and regulatory infrastructure for radiation safety that covers the practice of well logging with radiation sources is in place (see Section 2). In the case that well logging activities are to be conducted in a State in which regulations on radiation protection are not yet in place or do not meet the relevant international standards, the recommendations in this Safety Guide will provide general guidance on ensuring radiation safety in well logging.

Objective

1.9. The objective of this Safety Guide is to provide recommendations on how to meet the relevant requirements of IAEA Safety Standards Series No. GSR Part 3, Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards [9], with regard to the use of radioactive sources and radiation generators in well logging.

1.10. The guidance in this publication is aimed primarily at operating organizations that are authorized to undertake well logging with radiation sources, as well as their employees and radiation protection officers. The guidance will also be of interest to regulatory bodies and to designers, manufacturers, suppliers, and maintenance and servicing organizations of well logging equipment that contains radiation sources.

Scope

1.11. This Safety Guide provides recommendations on the use of radioactive sources and radiation generators in well logging, including in the manufacture, calibration and maintenance of well logging tools. It provides recommendations on radiation protection and safety for the storage, use and transport of such radiation sources.

1.12. This Safety Guide is concerned with...

Table of contents

• 1. INTRODUCTION
• REFERENCES
• Annex I OVERVIEW OF RADIOACTIVE SOURCES USED IN WELL LOGGING
• Annex II CONSIDERATIONS FOR A SAFETY ASSESSMENT FOR WELL LOGGING
• Annex III INFORMATION ON RADIATION SAFETY OF NEUTRON GENERATORS USED IN WELL LOGGING
• Annex IV CALCULATION OF RADIATION SHIELDING
• Annex V SUGGESTED STRUCTURE OF WELL LOGGING LOCAL RULES
• Annex VI EXAMPLES OF INCIDENTS INVOLVING RADIATION SOURCES IN WELL LOGGING
• CONTRIBUTORS TO DRAFTING AND REVIEW