Wired Drill Pipe Fault Location Using Impedance
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Solution Overview
Problem
Existing drilling systems with wired drill pipes face challenges in accurately locating intermittent faults during drilling, leading to unnecessary replacement of large sections of drill pipe, as faults can only be traced to within sections below the lowest operational repeater sub, making it difficult to identify failing pipes at the rig site.
Innovation Solution
A fault monitoring system that includes an impedance measuring system and a fault locator, which measures the input impedance of wired drill pipes and determines the propagation constant to accurately locate faults by analyzing the measured impedance and propagation constant, allowing for precise fault location within a few drill pipe joints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If repeater subs are spaced apart by large intervals (e.g., 500 meters) to extend communication range, then the communication coverage is improved, but the fault location precision deteriorates
Solution Approach 1:
The patent replaces the mechanical/physical approach of densely spacing repeater subs with an electrical measurement approach. Instead of using the physical position of repeater subs to locate faults, the system uses electrical impedance measurements and propagation constant analysis to precisely determine fault locations, substituting mechanical segmentation with electrical field-based detection.
Solution Approach 2:
The patent changes the measurement parameters from simple presence/absence detection at repeater sub locations to continuous electrical parameter measurements (impedance, propagation constant). By measuring these electrical parameters and analyzing their variations along the drill pipe, the system achieves precise fault location without requiring dense repeater sub spacing.
2Loss of substance
If fault location precision is improved to within a few joints, then the quantity of drill pipe replacement is reduced, but the device complexity increases
Solution Approach 1:
The fault monitoring system performs multiple functions: it measures impedance, determines propagation constants, locates faults, and provides precision information. This multi-functional approach consolidates what would otherwise require multiple separate systems into a single integrated solution, making the increased complexity worthwhile by dramatically reducing drill pipe replacement quantities.
Solution Approach 2:
The patent introduces an intermediary measurement system that indirectly detects faults through electrical parameter measurements rather than directly observing physical faults. The impedance measuring system and propagation constant analysis act as intermediaries, translating electrical measurements into precise fault location information, thereby reducing the need for extensive physical inspection and pipe replacement.
3Reliability
If intermittent faults are detected while drilling, then the reliability of fault location is improved, but the difficulty of detecting and measuring increases
Solution Approach 1:
The system performs preliminary impedance measurements and propagation constant determinations during normal drilling operations. By continuously monitoring electrical parameters while the drill pipe is in the borehole, the system is prepared to detect and locate intermittent faults as they occur, rather than waiting for complete system failure or requiring pipe extraction for inspection.
Solution Approach 2:
The patent implements a feedback mechanism where impedance measurements and propagation constant analysis provide continuous information about the electrical state of the drill pipe. This feedback loop allows the system to detect changes indicative of intermittent faults and locate them precisely, transforming the difficulty of detecting transient faults into a manageable measurement process through continuous monitoring and analysis.
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
Enables precise fault location in wired drill pipes, reducing the need for extensive pipe replacement and improving drilling efficiency by identifying faults while drilling, thus minimizing downtime and costs.
Implementation Method 1
The impedance measuring system is configured to measure, while drilling the borehole, an input impedance of the wired drill pipes
Implementation Method 2
The fault locator is configured to determine a propagation constant for the wired drill pipes, and to analyze the measured input impedance
Data Source
AI summary
Apparatus and methods for locating faults in inductively coupled wired drill pipe while drilling. In one embodiment, apparatus includes a drill string and a wired drill pipe fault monitor. The drill string includes a plurality of wired drill pipes. Each wired drill pipe includes an inductive coupler at each terminal end. The wired drill pipe fault monitor is coupled to the wired drill pipes. The fault monitor includes an impedance measuring system and a fault locator. The impedance measuring system is configured to measure, while drilling the borehole, an input impedance of the wired drill pipes. The fault locator is configured to determine a propagation constant for the wired drill pipes, and to analyze the measured input impedance and determine, as a function of the measured input impedance and the propagation constant, a location of a fault in the wired drill pipes.