Downhole Inductive Coupler Shielding for Low-Attenuation Telemetry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Downhole inductive couplers in wired pipe telemetry systems face challenges due to high loads, harsh conditions, and stray magnetic fields, leading to reduced efficiency and reliability in data transmission.
Innovation Solution
The use of an inductive coupler assembly with a housing, ferrites, and a wire configuration that includes a cladding or shell material with high permeability and conductivity to reduce power dissipation, along with a retention mechanism and shielding to mitigate the effects of stray fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If inductive couplers are used in wired pipe telemetry systems, then data transmission rate is improved, but attenuation increases and bandwidth decreases due to stray magnetic fields
Solution Approach 1:
A shield made of conductive material (such as copper) is introduced as an intermediary component between the inductive coupler and the pipe joint end. This shield acts as a mediator that intercepts and redirects stray magnetic fields, preventing them from entering unsuitable materials and causing energy losses. The shield effectively decouples the harmful electromagnetic interactions while allowing the inductive coupler to maintain its data transmission function.
Solution Approach 2:
The shield utilizes the stray magnetic fields that would otherwise be harmful by providing a controlled path for these fields through its conductive material. The shield converts the harmful stray fields into manageable electromagnetic interactions within the shield itself, where the energy is dissipated in a controlled manner rather than causing uncontrolled losses in surrounding materials. This transforms the harmful effect into a beneficial containment mechanism.
2Reliability
If inductive couplers are used in wired pipe telemetry systems, then data transmission capability is improved, but reliability decreases under harsh downhole conditions
Solution Approach 1:
The shield serves as a protective intermediary that isolates the inductive coupler from the harsh downhole environment and stray magnetic fields. By positioning the shield between the coupler and the external environment, it mediates the interaction, allowing the coupler to operate reliably while the shield absorbs and redirects harmful electromagnetic influences.
Solution Approach 2:
The shield is positioned in advance to prevent stray magnetic fields from affecting the inductive coupler before harmful interactions can occur. This preliminary protective measure blocks the path of stray fields, preventing them from causing reliability issues before they can impact the telemetry system's performance.
3Loss of energy
If shield material is added to the inductive coupler assembly, then power dissipation is reduced, but device complexity increases
Solution Approach 1:
The shield is implemented as a thin-walled cylindrical structure made of conductive material, utilizing a simple geometric form that minimizes material usage and manufacturing complexity. This thin-film approach provides effective electromagnetic shielding while adding minimal structural complexity to the overall assembly. The simple cylindrical geometry allows for straightforward integration into the existing inductive coupler design.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances the efficiency of data transmission by minimizing attenuation and increasing bandwidth, thereby improving the reliability of the telemetry system even under harsh downhole conditions.
Implementation Method 1
A wire is disposed in an interior channel of each ferrite
Implementation Method 2
Data transmission involves transmitting an electrical signal through an electrical conductor in a first wired pipe, converting the electrical signal to a magnetic field upon leaving the first wired pipe using an inductive transducer at an end of the first wired pipe, and converting the magnetic field back into an electrical signal using an inductive transducer at an end of the second wired pipe
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Inductive coupler assemblies for controlling the stray magnetic fields of an inductive coupler to reduce the associated losses are disclosed. This results in reduced attenuation (increased efficiency) of the inductive coupler even in the presence of gaps. The assembly includes an inductive coupler having a housing, a biasing element, and a retention mechanism. The assembly further includes a wire surrounded by a ring of flux channel material disposed in the housing. In some embodiments, the retention mechanism is adapted for removal of the inductive coupler from a pipe joint end. The biasing element may be a circumferential spring disposed between the housing and the pipe joint end. The retention mechanism may be a retention snap ring, press fit, or threaded, to removably couple the housing to the pipe joint end.