MWD Magnetic Interference Detection via Lateral Axial Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Measurement while drilling (MWD) systems face challenges in accurately determining magnetic interference, particularly from drill strings and environmental factors, which affects the precision and reliability of directional well drilling, leading to increased costs and potential 'dry holes' due to imperfect geomagnetic models and limited sensitivity of magnetometers.
Innovation Solution
The implementation of a system with three-axis accelerometer and magnetometer sensors, along with temperature sensors, and a non-transitory computer readable memory device to continuously monitor and process magnetic field data, distinguishing between lateral and axial interference, and adjusting the drilling trajectory in real-time to minimize deviations and optimize reservoir exploration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetometers are used to measure magnetic field strength for directional drilling, then the ability to determine well trajectory is improved, but the measurement precision deteriorates due to magnetic interference from drill strings and environmental factors
Solution Approach 1:
The patent segments the magnetic field measurement into three independent components: lateral magnetic field strength (BLAT), axial magnetic field strength (BAX), and total magnetic field strength (BTOT). By separating the measurement into these segments, the system can identify and isolate the harmful axial interference from the useful lateral measurement, allowing for corrected trajectory determination despite the presence of magnetic interference from drill strings and environmental factors.
Solution Approach 2:
The patent introduces an intermediary calculation approach using the relationship BLAT² + BAX² = BTOT² to eliminate the harmful axial magnetic field component. This mathematical intermediary allows the system to compute the lateral magnetic field strength without being affected by the axial interference, effectively mediating between the noisy measurements and the desired accurate trajectory data.
2Reliability
If magnetometers are used to detect magnetic interference, then the detection capability is improved, but the reliability deteriorates due to limited sensitivity and imperfect geomagnetic models
Solution Approach 1:
The patent implements a feedback mechanism where the system continuously monitors the magnetic field components (BLAT, BAX, BTOT) and compares them against expected values based on geomagnetic models. When deviations are detected, the system uses this feedback to identify magnetic interference and adjust the trajectory calculation accordingly, improving reliability despite the limited sensitivity of individual magnetometers and imperfections in geomagnetic models.
Solution Approach 2:
The patent changes the measurement parameters from traditional single-value magnetic field strength measurements to a three-component parameter set (BLAT, BAX, BTOT). This parameter transformation allows the system to distinguish between valid magnetic field variations and interference, improving reliability by providing multiple independent parameters that can be cross-validated against each other and against geomagnetic model predictions.
3Productivity
If directional drilling is implemented to access reservoirs, then the productivity is improved, but the device complexity increases due to multiple sensors and real-time processing requirements
Solution Approach 1:
The patent makes the magnetometer system multi-functional by using the same three sensors (measuring BLAT, BAX, and BTOT) for multiple purposes: detecting magnetic interference, determining well trajectory, and providing feedback for real-time adjustments. This universal approach improves productivity by eliminating the need for separate systems for each function, despite the increased complexity of the sensor array and processing requirements.
Solution Approach 2:
The patent implements continuous real-time processing of magnetic field data throughout the drilling operation, providing uninterrupted feedback for trajectory adjustments. This continuous action improves productivity by enabling dynamic adaptation to changing conditions, while the system manages complexity through automated real-time calculations rather than manual intervention.
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
This approach enhances the accuracy and anti-disturbance ability of MWD systems, allowing for precise guidance of the drill bit through magnetic obstacles, reducing project costs and improving the confidence in reservoir characterization by accurately computing lateral and axial magnetic field strengths and making real-time adjustments.
Implementation Method 1
magnetic sensors have been used in a number of applications over the years... the magnetic field of the earth is primarily produced within its interior but also extends from the earth's outer core to the magnetopause thereby responsible for providing a shielding effect to the earth
Implementation Method 2
a three-axis accelerometer and a three-axis magnetometer... to measure the drill bit's acceleration and position
Data Source
AI summary
A method and a system implementing the method, are disclosed for computing magnetic interferences in measurement while drilling operations, using the retrieved lateral, and axial magnetic interferences of the measurement while drilling downhole tool system. With the disclosed method and system of implementing the method, it can be determined whether the source of the magnetic interference is from the measurement while drilling downhole tool system lateral direction or its axial direction. When magnetic field strength is abnormal, the lateral and axial magnetic interferences are monitored, and then compared against their values before the abnormal magnetic field strength. This way the direction of the magnetic interference is analyzed to eliminate or judge the cause of the interference, and properly guide the measurement while drilling downhole tool system towards its reservoir or well location.