Combined Radioactive Source Shielding for Wellbore Logging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Radiation-based spectroscopy in wellbore drilling operations poses a risk of excessive radiation exposure to personnel due to the use of chemical sources that emit dangerous levels of gamma and neutron radiation, which are handled by multiple workers during assembly and operation of detector systems.
Innovation Solution
A detector system design that incorporates a combined chemical source for emitting gamma and neutron radiation, along with sets of radiation detectors, is integrated with a containment pig that shields personnel from radiation emissions, allowing for controlled exposure and reduced handling risks by using a containment insert to block radiation when not in use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If chemical sources emitting gamma and neutron radiation are used for spectroscopy in wellbore drilling operations, then accurate logging of formation properties is achieved, but radiation exposure to personnel increases to dangerous levels
Solution Approach 1:
The radioactive source is nested within a containment pig that can be inserted into and removed from the detector system. The source is further contained within a containment vessel inside the pig. This nested structure allows the source to be protected during handling and storage while enabling its use during operation, resolving the contradiction between measurement capability and radiation safety.
Solution Approach 2:
The radioactive source is extracted from the detector system by removing the containment pig after logging operations are complete. This separation allows the source to be stored in a shielded container away from personnel, eliminating radiation exposure risks while maintaining the system's logging capability when needed.
2Ease of operation
If multiple workers handle the radioactive chemical source during assembly and operation, then the detector system can be assembled and operated, but the risk of excessive radiation exposure to personnel increases
Solution Approach 1:
The containment pig is designed to be inserted into the detector system housing, and the source is nested within the pig. This nested design allows workers to handle the outer containment structures rather than directly manipulating the radioactive source, reducing radiation exposure risk while maintaining assembly capability.
Solution Approach 2:
The containment pig acts as an intermediary between workers and the radioactive source. Workers interact with the pig and its external features rather than directly handling the source, which mediates the interaction and reduces radiation exposure while enabling assembly and operation tasks.
3Object-affected harmful factors
If the containment insert is used to block radiation when not in use, then radiation exposure to personnel is reduced to safe limits, but the system complexity increases
Solution Approach 1:
The containment insert is nested within the containment pig, which itself is inserted into the detector system housing. This nested arrangement provides multiple levels of containment and shielding without requiring separate complex systems, reducing radiation exposure while managing structural complexity through integrated design.
Solution Approach 2:
The containment pig serves multiple functions: it provides radiation shielding, acts as a transport container, facilitates easy insertion and removal from the detector system, and provides structural support for the source assembly. This multi-functionality reduces the need for separate components, managing system complexity while effectively reducing radiation exposure.
Data Source
AI summary
A first set of radiation detectors may be disposable on the a drill string, wherein the first set of radiation detectors are capable of detecting gamma radiation and neutron radiation; and a combined chemical source spaced from the first set of radiation detectors, wherein the combined chemical source comprises a gamma radiation emitting material and a neutron radiation emitting material. The first set of radiation detectors and combined chemical source may be used in methods for logging a wellbore.