Inertial Navigation Fine Alignment for Drilling Attitude Accuracy
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Solution Overview
Problem
Current attitude measurement methods for directional drilling in harsh environments, such as high temperature and strong vibration, face challenges with drift error and bias repeatability, leading to inaccurate well trajectory control and increased exploration costs.
Innovation Solution
A Kalman-based two-position alignment method that assesses measurement data validity and corrects for inertial instrument errors using quaternion updates and zero-velocity corrections, enhancing fault tolerance and alignment accuracy without altering the precision of the inertial instruments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing calibration methods are used for gyro measurement while drilling, then the calibration process can be completed, but the calibration accuracy is limited by drift error and bias repeatability in harsh environments
Solution Approach 1:
The patent applies preliminary action by performing multiple pre-calibration steps before the actual calibration. The method includes preliminary calibration at different orientations (0°, 90°, 180°, 270°) to establish baseline drift characteristics, followed by compensation calculations that use these pre-collected data to correct subsequent measurements. This preliminary characterization of drift behavior enables more accurate calibration despite harsh environment conditions.
Solution Approach 2:
The patent implements feedback through iterative calibration procedures where measurement results are continuously fed back to adjust calibration parameters. The system performs repeated calibration cycles, comparing measured values against expected values, calculating errors, and adjusting calibration coefficients accordingly. This closed-loop feedback mechanism progressively reduces drift error and improves calibration accuracy in high-temperature and high-vibration environments.
2Adaptability or versatility
If inertial instruments are used in harsh environments (high temperature and strong vibration), then attitude measurement can be performed, but drift error increases and affects measurement accuracy
Solution Approach 1:
The patent replaces mechanical stabilization methods with computational correction approaches. Instead of using mechanical gimbals or physical stabilization mechanisms to counteract vibration and temperature effects, the system uses algorithmic drift compensation and calibration techniques. The method substitutes mechanical precision requirements with software-based error correction, allowing the inertial instrument to operate in harsh environments while maintaining measurement accuracy through digital processing.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting calibration parameters based on environmental conditions. The system monitors temperature and vibration levels, and automatically adjusts drift compensation parameters, calibration coefficients, and filtering characteristics accordingly. This adaptive parameter adjustment enables the system to maintain optimal performance across varying environmental conditions, from high temperature to strong vibration scenarios.
3Duration of action of stationary object
If the gyroscope operates under strong vibration and high temperature, then drilling measurement can continue, but the repeatability error increases
Solution Approach 1:
The patent implements periodic action through regular calibration intervals and repeated measurement cycles. The system performs calibration at scheduled intervals during drilling operations, conducting periodic checks of drift characteristics and updating compensation parameters accordingly. This periodic recalibration maintains bias repeatability over extended operation periods, counteracting the cumulative effect of environmental stress on the gyroscope.
Solution Approach 2:
The patent applies beforehand cushioning by pre-compensating for expected drift and repeatability errors. The method establishes compensation models based on historical performance data and environmental conditions, then applies these compensations in advance to correct measurements before errors can significantly impact accuracy. This proactive error cushioning maintains reliable operation throughout the measurement period despite harsh environmental conditions.
Data Source
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AI summary
The present invention provides an attitude measurement method, which relates to the technical field of measurement while drilling in directional drilling, which can improve the observability of inertial instrument errors, suppress the repeatability errors of gyroscopes and improve the attitude measurement accuracy. The method adopts the method of fine alignment at multiple positions to carry out initial alignment; the method includes the steps of: S1, taking current attitude data and velocity data of the strapdown inertial navigation system as first initial values, and performing fine alignment at a first position; S2, changing the position of a strapdown inertial navigation system to an nth position, and performing attitude update and velocity update according to the last fine alignment result in the position changing process; and S3, taking the results of attitude update and velocity update as the nth initial values, performing the nth fine alignment at the nth position to complete the initial alignment of the strapdown inertial navigation system, thereby realizing attitude measurement. The solution of the present invention is suitable for measuring the horizontal attitude and azimuth of the whole inclined section of a horizontal well, especially the application of directional drilling gyro measurement while drilling in the attitude measurement of large inclined wells and horizontal wells.