Borehole Depth Monitoring Using Reflected Probe Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sensors used for monitoring mechanically drilled boreholes cannot survive the extreme temperatures generated by high-power millimeter-wave beams used to drill through rock, as they require physical contact with the bottom of the borehole.
Innovation Solution
A system that uses a millimeter-wave drilling beam to create boreholes while monitoring the depth and rate of penetration from the ground surface, employing a transmission line to guide a probe signal to the borehole bottom, where it reflects or scatters, and a depth/rate-of-penetration monitor to determine these parameters based on the amplitude, frequency, or time of flight of the return beam, without requiring the monitor to be at the extreme temperatures of the borehole.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sensors are used to monitor borehole depth, then measurement capability is provided, but the sensors cannot survive the extreme temperatures at the borehole bottom
Solution Approach 1:
A probe signal is introduced as an intermediary that travels through the borehole to the bottom and reflects back. This probe signal acts as a mediator that can withstand the extreme temperatures while carrying measurement information, eliminating the need for physical sensors to be placed at the borehole bottom.
Solution Approach 2:
The patent replaces the mechanical contact-based sensor system with an electromagnetic probe signal system. The probe signal transmits measurement data without physical contact with the borehole bottom, substituting mechanical sensing with electromagnetic wave propagation and reflection.
2Measurement precision
If the monitor is placed at the borehole bottom to directly measure depth, then measurement accuracy is improved, but the monitor must withstand extreme temperatures and pressure
Solution Approach 1:
The probe signal serves as an intermediary that carries measurement information from the borehole bottom to the surface monitor. This allows the monitor to remain on the ground surface at ambient conditions while still obtaining accurate depth measurements from the extreme environment at the borehole bottom.
Solution Approach 2:
The measurement system is segmented into two separate locations: the probe signal source and processing equipment remain on the ground surface at safe conditions, while the probe signal itself ventures into the extreme environment to perform measurements. This segmentation separates the monitoring function from the harsh environment.
3Temperature
If a probe signal is used to monitor from the surface, then the monitor can operate at ambient temperature, but the system complexity increases due to signal transmission and processing requirements
Solution Approach 1:
The probe signal system serves multiple functions: it measures borehole depth, determines penetration rate, and can detect borehole conditions. By using a single probe signal for multiple measurements, the system avoids the need for separate dedicated sensors for each function, thereby managing complexity while providing comprehensive monitoring.
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 accurate monitoring of borehole depth and penetration rate from a safe distance, avoiding the need for sensors to withstand extreme temperatures, thus ensuring reliable operation and data collection during the drilling process.
Implementation Method 1
The transmission guides the probe signal to the bottom of the borehole, and at least a portion of the probe signal reflects and/or scatters from the bottom of the borehole as a return beam
Implementation Method 2
at least a portion of the probe signal reflects and/or scatters from the bottom of the borehole as a return beam
Implementation Method 3
A high-power millimeter-wave beam produced by a gyrotron can make a borehole in rock by melting and/or vaporizing the rock
Implementation Method 4
A high-power millimeter-wave beam produced by a gyrotron can make a borehole in rock by melting and/or vaporizing the rock
Implementation Method 5
The return beam is coupled out of the transmission line and mixed with a local oscillator to produce an intermediate frequency beam
Data Source
AI summary
Apparatus and methods are described for drilling deep boreholes with millimeter-wave radiation in earthen materials to access deep resources such as geothermal heat. Borehole depth and temperature at the bottom of the borehole can be monitored with probe signals and/or radiative emission from the bottom of the borehole.