Faraday Crystal Fiber Optic Sensor for Wellbore Corrosion Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional casing collar locators in the petroleum drilling industry face inaccuracies due to tubing elasticity, thermal expansion, non-linearity of the well bore, and interference with other instrumentation, and are limited by the need for dynamic operation and high power consumption, making precise location of casing collars and corrosion detection challenging.
Innovation Solution
A fully fiber-optic sensor system using Faraday crystals to detect magnetic permeability anomalies by passing de-polarized light through a magnetic field, which senses mass-related changes in casings, allowing for accurate location of casing collars and corrosion zones without the need for dynamic operation or high power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional casing collar locators are used, then dynamic operation is required to detect collar positions, but this leads to high power consumption and reduced measurement precision
Solution Approach 1:
The patent replaces conventional electromagnetic sensing mechanisms with a fiber optic-based magnetic field sensing system. The fiber optic sensor detects changes in magnetic field strength caused by ferromagnetic collar materials, eliminating the need for high-power electromagnetic generators while achieving precise collar location measurements through optical field interactions.
Solution Approach 2:
The invention utilizes changes in magnetic field parameters (field strength and distribution) as the fiber optic sensor passes near or contacts collar joints. By measuring these magnetic field parameter variations through the fiber optic probe, the system achieves accurate collar detection without requiring dynamic mechanical operation or high power consumption.
2Measurement precision
If conventional magnetic field-based locators are used, then collar detection is possible, but interference with other instrumentation and tubing elasticity affect measurement precision
Solution Approach 1:
The fiber optic sensor acts as an intermediary that indirectly measures collar positions by detecting magnetic field changes rather than directly interacting with the collar joint mechanically. This intermediary approach eliminates direct mechanical contact issues (tubing elasticity, drag) and electromagnetic interference with other downhole instrumentation while maintaining measurement precision.
3Measurement precision
If wire line indicators are used in highly deviated holes, then collar location can be determined, but the force of gravity positioning causes reliability issues
Solution Approach 1:
The patent replaces gravity-dependent mechanical positioning systems with a magnetic field-based fiber optic sensing system. The fiber optic probe detects collar positions through magnetic field interactions that are independent of gravitational forces, enabling reliable and accurate collar location measurements in highly deviated and horizontal wellbores where gravity-based systems fail.
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
The system provides precise location of casing collars and corrosion zones with improved accuracy and reduced interference, enabling accurate depth measurements and corrosion detection in well holes, even in deviated holes, with enhanced sensitivity and reduced signal noise.
Implementation Method 1
A target such as a casing collar presents an additional mass which will appear as permeability anomalies along the length of the casing. Similarly, a corroded section of borehole casing has less mass than a corresponding section of uncorroded casing. The invention permits detection of the permeability anomalies that exist as a result of the differences in mass
Implementation Method 2
The sensing element uses principles of optical diffraction and polarization shift to sense and telemeter permeability changes in the target elements
Implementation Method 3
A fully fiber optics based sensor system using a Faraday crystal to detect magnetic permeability anomalies of target elements
Data Source
AI summary
Systems and methods for optically determining casing collar and/or corrosion locations within boreholes, using the diffraction effect of Faraday crystals through which depolarized continuous light is transmitted within optical fibers.