Retractable Nozzle Optical Sensing for Laser Drilling
Solution Overview
Problem
Conventional laser drilling tools face challenges in accurately characterizing rock types during the drilling process due to debris and by-products generated by high power laser interactions, which contaminate the reflected light and hinder effective spectroscopy and luminosity analysis.
Innovation Solution
A laser drilling tool assembly with a retractable nozzle and optical sensing elements that extend closer to the downhole target, allowing for real-time acquisition of reflectance and spectroscopic data, and employing purging nozzles to clear debris and maintain a clear path for the laser beam, along with machine learning analytics for data analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the optical sensing elements are positioned closer to the downhole target, then the measurement precision is improved, but the contamination from debris increases
Solution Approach 1:
The optical sensing elements are mounted on a retractable nozzle that can extend and retract dynamically. During drilling operations, the nozzle extends to position the sensors closer to the target for better measurement precision, then retracts to minimize debris contamination. This dynamic positioning resolves the contradiction between needing close proximity for accurate measurements and needing distance to avoid contamination.
2Measurement precision
If a retractable nozzle is used to extend optical sensing elements, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The retractable nozzle serves multiple functions: it acts as both a support structure for mounting optical sensing elements and a positioning mechanism for adjusting their distance from the target. This multi-functionality reduces the need for separate components, thereby minimizing the increase in device complexity while still achieving improved measurement precision.
3Measurement precision
If purging nozzles are introduced to clear debris, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
A purging medium (such as gas or fluid) is introduced as an intermediary substance to clear debris from the optical path between the laser source and target, and from the sensing elements. This intermediary effectively improves optical signal quality and measurement precision by removing contaminants without requiring direct mechanical intervention in the optical path.
Solution Approach 2:
The purging system utilizes pneumatic or hydraulic principles to generate controlled flows of purging medium through dedicated nozzles positioned near the optical path. This approach leverages well-established fluid dynamics to achieve debris removal, minimizing the need for complex mechanical systems while effectively improving measurement precision.
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 real-time and in-situ characterization of rock types by minimizing contamination from debris, providing accurate data on rock types and environmental conditions, and improving the efficiency of the laser drilling process.
Implementation Method 1
directing the directed beam onto a motorized master, where the controlled beam moves in a movement pattern, introducing the controlled beam to a laser head, sublimating the formation to produce the opening
Implementation Method 2
a laser beam at a downhole location of a wellbore is directed to a target area of a wellbore wall to be perforated
Implementation Method 3
characterization and classification of rocks can reveal insights about the layered formation, including fluid saturation
Implementation Method 4
one or more spectral sensors. The spectral sensor may include at least one of: a scanning sensor, or a Fourier-transform infrared spectroscopy (FTIR) sensor
Data Source
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AI summary
Some implementations of the present disclosure provide a laser drilling tool assembly comprising: (i) a body that includes: a first segment configured to receive an input beam from a laser source and couple the input beam to provide an irradiation beam to irradiate a downhole target, and a second segment housing one or more purging pipes; and (ii) a tool head that includes: a retractable nozzle; and one or more optical sensing elements mounted on the retractable nozzle, wherein when the downhole target is being irradiated by the irradiation beam, the retractable nozzle is extended towards the downhole target such that the one or more optical sensing elements are positioned closer to the downhole target.