Multiple-Surface Excitation for Wellbore Location Without Direct Coupling
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Solution Overview
Problem
Existing electromagnetic induction tools for determining the location of a second wellbore relative to a target wellbore suffer from undesired direct coupling due to conduction currents on metallic bottom hole assemblies, leading to inaccurate distance and direction measurements.
Innovation Solution
The method employs a multiple excitation technique using reciprocal electromagnetic sources and multiple sensors to measure magnetic fields from pre-existing conductive members in the target wellbores, reducing interference and enhancing measurement accuracy by leveraging reciprocity and additional measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electromagnetic induction tools use direct current injection or coil antenna transmission to obtain current on conductive members, then the ability to determine direction and distance between wellbores is enabled, but direct coupling signals are created that reduce measurement accuracy
Solution Approach 1:
The system segments the measurement process by using multiple separate excitation sources (first and second electromagnetic sources) positioned in different wellbores, rather than relying on a single direct coupling path. This segmentation allows the receiver to distinguish between direct coupling signals and indirect electromagnetic induction signals through spatial and temporal separation of the excitation events.
Solution Approach 2:
The invention introduces the subsurface formation as an intermediary medium. Instead of directly measuring current on the conductive member through direct coupling, the system uses electromagnetic sources that induce currents in the formation, which then couple to the conductive member. This indirect path through the formation acts as a mediator that filters out direct coupling interference while preserving the location information.
2Measurement precision
If multiple electromagnetic sources and sensors are used to reduce measurement errors, then location determination precision is improved, but device complexity increases
Solution Approach 1:
The electromagnetic sources and sensors are designed to serve multiple functions. The same electromagnetic sources used for location determination can also be used for formation evaluation and other wellbore measurements. The sensors can detect multiple types of signals (direct coupling, electromagnetic induction, natural formation signals) and are used for various measurement purposes, reducing the need for separate dedicated equipment for each function.
Solution Approach 2:
Instead of placing multiple sensors in a single wellbore to measure signals from multiple sources, the invention inverts the approach by placing multiple electromagnetic sources in different wellbores and using a single receiver to measure the induced signals. This inversion reduces the overall number of sensors required while maintaining measurement precision through the use of multiple spatially distributed excitation points.
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 significantly reduces measurement errors, providing precise determination of the second wellbore's location with respect to the target wellbores, improving drilling accuracy and safety by minimizing interference and enhancing robustness in various drilling scenarios.
Implementation Method 1
inducing a current on a conductive member by transmitting electromagnetic fields by coil antennas positioned in a second wellbore
Implementation Method 2
The injection of current from the electromagnetic induction tools may induce a current along the bottom hole assembly, which may create a direct signal
Implementation Method 3
Receivers may be used to sense and record the signal. The signal may be used to determine a position of the second wellbore in relation to the target wellbore
Data Source
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AI summary
A method and system for determining a position of a second production wellbore. The method may comprise inducing a first current into a first conductive member with a first source, emitting a first magnetic field generated by the first current from the first conductive member into a formation, inducing a second current into a second conductive member with a second source, emitting a second magnetic field generated by the second current from the second conductive member into the formation, disposing an electromagnetic sensor system into the second production wellbore, recording the first magnetic field with the at least one sensor from the formation, and recording the second magnetic field with the at least one sensor from the formation. The system may comprise a first source, an electromagnetic sensor system, at least one sensor and an information handling system configured to determine the position of the second production wellbore.