Tri-axial Antenna Array for 3D Magnetic Field Source Location
Solution Overview
Problem
Conventional horizontal directional drilling (HDD) systems face challenges in accurately locating and tracking a transmitter in both fore-aft and left-right directions, especially when the receiver is positioned directly over the transmitter, as they rely on magnetic dipole fields which lack a y-component at this position, limiting simultaneous three-dimensional tracking.
Innovation Solution
The system employs a tri-axial antenna arrangement with three orthogonal antennas, each measuring the magnetic field along its specific axis, and a processor to calculate the transmitter's location in 3D space using magnetic field measurements from multiple points, allowing for accurate positioning without requiring the receiver to be directly above the transmitter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a magnetic dipole field is used for tracking, then the transmitter can be located in most positions, but the system fails when the receiver is directly over the transmitter due to lack of y-component
Solution Approach 1:
The patent transitions from a two-dimensional magnetic dipole field measurement (lacking y-component at certain positions) to a three-dimensional magnetic gradient field measurement using tri-axial antennas. By adding the third dimension of measurement capability through orthogonal antenna arrangements, the system achieves complete spatial coverage including the previously problematic position directly over the transmitter.
2Measurement precision
If conventional magnetic dipole field tracking is used, then the system structure remains simple, but simultaneous three-dimensional tracking accuracy is limited
Solution Approach 1:
The patent segments the tracking function into three independent orthogonal measurements using separate tri-axial antenna arrangements. Each antenna measures the magnetic gradient field along its specific axis, and the processor combines these segmented measurements to calculate precise three-dimensional transmitter location, achieving high accuracy through functional segmentation.
Solution Approach 2:
The patent introduces a processor as an intermediary that receives magnetic gradient field measurements from multiple tri-axial antenna arrangements and calculates the transmitter's three-dimensional location. This intermediary component integrates the complex measurements and transforms them into accurate position information, managing the system's complexity centrally.
3Measurement precision
If the receiver must be positioned away from directly over the transmitter, then measurement accuracy improves, but the number of steps and repositioning required increases
Solution Approach 1:
The patent enables the tracking system to serve itself by using the tri-axial antenna arrangements to provide complete spatial measurement capability from any receiver position, including directly over the transmitter. The system eliminates the need for operator intervention to reposition the receiver, as the enhanced measurement capability automatically provides accurate tracking data from all positions.
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 enables precise, simultaneous three-dimensional location of the downhole tool assembly during HDD operations, improving tracking accuracy and reducing the need for multiple steps or repositioning, thus enhancing drilling precision and efficiency.
Implementation Method 1
Each antenna arrangement comprises three orthogonal antennas which measure the magnetic field along their specific axis
Implementation Method 2
The first winding and the fourth winding define an aperture area, the second winding and the fifth winding define an aperture area, and the third winding and the sixth winding define an aperture area
Data Source
AI summary
A receiver and tracking system for identifying a location of a magnetic field source. In a preferred embodiment a plurality of tri-axial antennas are positioned at three distinct points on a receiver frame. Each antenna detects a magnetic field from a source and a processor is used to determine a location of the source relative to the frame using the antenna signals. Each tri-axial antenna comprises three windings in each of three channels defined by a support structure. The windings each define an aperture area. The windings have substantially identical aperture areas and have a common center point. The receiver may to display to the operator the relative location of the field source or may direct the operator to a spot directly above the field source.