Weight on Bit Sensor Calibration via Borehole Curvature Prediction
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Solution Overview
Problem
Current drilling operations face challenges in accurately determining the true weight applied to the drill bit due to masking effects from gravity and hole curvature, leading to inaccurate weight measurements and potential damage to drilling equipment.
Innovation Solution
A method and system for automatic weight on bit sensor calibration, which involves taking a first survey recording at a specific depth to measure inclination and azimuth, calculating a predicted borehole curvature at a second depth, and using a weight correction value to calibrate the sensor sub, thereby correcting weight measurements in real-time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If weight measurements are taken without correction for hole curvature and gravity effects, then measurement process is simple and fast, but measurement precision deteriorates due to masking effects
Solution Approach 1:
The system performs preliminary calibration by calculating predicted borehole curvature using minimum curvature calculations based on survey data before taking weight measurements. This preliminary action establishes correction values that compensate for gravity and hole curvature effects, enabling accurate weight measurements without requiring complex real-time adjustments during drilling operations.
Solution Approach 2:
The invention introduces an intermediary correction process that uses survey data and minimum curvature calculations to determine borehole curvature. This intermediary information serves as a mediator between the raw sensor measurements and the true weight values, allowing the system to account for masking effects without directly measuring all underlying parameters.
2Measurement precision
If survey measurements are taken frequently to improve curvature accuracy, then measurement precision improves, but loss of time increases due to repeated survey operations
Solution Approach 1:
The system uses a partial action approach by performing minimum curvature calculations using existing survey data without requiring complete re-surveying. The calibration process applies corrections based on available inclination and azimuth data, providing sufficient curvature accuracy for weight measurement correction without the need for excessive survey operations.
Solution Approach 2:
The invention replaces the mechanical survey operation with a computational approach. Instead of physically re-positioning survey equipment to measure curvature at multiple points, the system uses minimum curvature calculations based on existing survey data to predict borehole curvature, significantly reducing the time required while maintaining measurement precision.
3Productivity
If real-time weight correction is implemented, then productivity improves through optimized drilling parameters, but device complexity increases due to continuous calibration requirements
Solution Approach 1:
The system implements feedback by continuously monitoring weight measurements and using minimum curvature calculations to update correction values in real-time. This feedback mechanism allows the system to adapt to changing borehole conditions and maintain accurate weight measurements throughout the drilling operation, enabling optimized drilling parameters based on true weight information.
Solution Approach 2:
The calibration system performs self-service by automatically calculating correction values using minimum curvature calculations based on survey data already being collected during normal drilling operations. The system uses existing operational data to maintain itself, eliminating the need for separate manual calibration procedures and reducing the impact of complexity on overall system operation.
Data Source
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AI summary
Disclosed are systems and methods for automatic weight on bit sensor calibration and regulating buckling of a drillstring. One method includes taking a first survey recording at a first depth within a borehole, the first survey recording providing inclination and azimuth of a drillstring at the first depth, measuring a weight on a drill bit at the first depth with a sensor sub arranged on a bottom hole assembly, the bottom hole assembly forming part of the drillstring and the drill bit being disposed at an end of the drillstring, calculating a predicted borehole curvature at a second depth within the borehole, the predicted curvature including a predicted inclination and a predicted azimuth of the drillstring at the second depth, calculating a weight correction value based on the predicted hole curvature, and calibrating the sensor sub with the weight correction value.