EM Telemetry Signal Propagation Across Drill String Gaps
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Solution Overview
Problem
Electromagnetic (EM) signal propagation across long distances in drill pipes is hindered by signal attenuation and latency issues, particularly in nonconductive gaps and 'dead zones' outside the casing, where repeaters are needed to maintain signal fidelity, but their design poses challenges in latency and data rate, and mechanical failures can occur due to stress and thermal cycling.
Innovation Solution
The use of multiple, selectable nonconductive gaps with switchable repeaters and mechanical stress sensors to optimize signal propagation, reduce latency, and predict component failure, allowing for continuous operation and redundancy in EM telemetry systems, with narrow gaps and toroids for efficient current induction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If repeaters are used to propagate EM signals across gaps in drill pipes, then signal fidelity is maintained, but latency increases and data rate decreases
Solution Approach 1:
The drill pipe is divided into multiple sections with nonconductive gaps between them, allowing EM signals to be transmitted across segmented sections without requiring repeaters at each gap location. This segmentation enables direct signal propagation while maintaining system integrity.
Solution Approach 2:
Nonconductive gaps serve as intermediaries that allow EM signal transmission between conductive drill pipe sections without requiring active repeater components. The gaps enable passive signal coupling, eliminating the need for powered devices that would introduce latency.
2Loss of energy
If repeaters are deployed to maintain signal across long distances, then signal attenuation is reduced, but device complexity and mechanical failure risk increase
Solution Approach 1:
The drill pipe system uses its own structure (the conductive pipe sections and nonconductive gaps) to propagate EM signals without requiring separate active repeater devices. The system serves itself by utilizing the natural electromagnetic coupling between sections, eliminating complex external equipment.
Solution Approach 2:
The patent replaces mechanical repeater devices with an electromagnetic field-based signal propagation system. Instead of using physical components that require maintenance and can fail mechanically, the system uses EM field coupling across nonconductive gaps, which has no moving parts and requires no mechanical maintenance.
3Ease of operation
If nonconductive gaps are used between pipe sections for signal propagation, then signal transmission is enabled, but signal attenuation increases in dead zones
Solution Approach 1:
The patent utilizes electromagnetic field dimensions (electric and magnetic field components) to propagate signals across the nonconductive gaps. By operating in the electromagnetic field domain rather than relying solely on direct electrical contact, the system enables signal transmission through dimensions that bypass the attenuating effects of dead zones.
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 approach enhances EM telemetry reliability by minimizing signal attenuation, reducing mechanical failures, and maintaining system integrity through gap selection and stress monitoring, thereby improving data transmission rates and operational efficiency in drilling operations.
Implementation Method 1
narrow gaps and toroids for efficient current induction
Data Source
AI summary
In some embodiments, an apparatus and a system, as well as a method and an article, may operate to monitor a first condition associated with transmitting or receiving a signal in a formation or on a drill string, or both, over a first selected interval of a drill string located down hole; to monitor a second condition associated with transmitting or receiving the signal in the formation or on the drill string or both, over a second selected interval of the drill string; to compare the first condition to the second condition to provide a comparison result; and based on the comparison result, to select one of the first selected interval or the second selected interval to transmit or receive the signal in the formation or on the drill string, or both. Additional apparatus, systems, and methods are disclosed.