Electromagnetic Ranging Tool with Combined Electrode and Coil Excitation
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Solution Overview
Problem
Existing electromagnetic ranging methods in subterranean operations face challenges in accurately determining the location and direction of target wellbores, particularly at T-intersections and in environments with conductive muds, due to limitations in electrode and coil excitation techniques, such as ambiguity in direction and sensitivity to formation resistivity.
Innovation Solution
Combining electrode and coil excitation methods on a bottom-hole assembly, with joint inversion and processing to maximize synergy, utilizing common quality factors to improve accuracy and robustness, and optimizing hardware placement for minimal extra hardware requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electrode excitation is used to induce current on conductive member, then ranging measurement can be obtained, but direction ambiguity occurs particularly at T-intersections
Solution Approach 1:
The patent combines electrode excitation and coil excitation methods into a unified ranging system. The electrode source induces current on the conductive member while coil antennas detect the resulting electromagnetic field. This merging of excitation methods allows the system to resolve direction ambiguity that plagues individual methods, particularly at T-intersections, while maintaining ranging measurement accuracy.
Solution Approach 2:
The patent introduces coil antennas as an intermediary detection mechanism that works in conjunction with electrode excitation. The coil antennas detect the electromagnetic field generated by current induced on the conductive member, providing additional directional information that resolves the ambiguity inherent in electrode-only methods.
2Measurement precision
If coil antennas are used to induce current on conductive member, then ranging measurement can be obtained, but sensitivity to formation resistivity limits performance
Solution Approach 1:
The patent merges electrode excitation with coil detection to create a hybrid system that overcomes the formation resistivity sensitivity limitation of coil-only methods. The electrode source provides a more stable current induction mechanism that is less affected by formation resistivity variations, while coil antennas maintain their advantage in directional detection.
Solution Approach 2:
The patent creates a composite excitation system combining electrode and coil components. This composite approach leverages the strengths of both methods: electrode excitation provides stability against formation resistivity effects, while coil detection provides directional information, resulting in a robust ranging system.
3Reliability
If multiple excitation sources are combined to improve accuracy, then ranging reliability increases, but device complexity increases
Solution Approach 1:
The patent designs the electromagnetic ranging tool with multi-functional components that serve multiple purposes. The coil antennas function both as detection elements for electromagnetic field measurement and as part of the integrated excitation-detection system. This universality reduces the need for separate dedicated components, thereby limiting the increase in device complexity while maintaining improved reliability through combined excitation methods.
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
Enhances the accuracy and reliability of electromagnetic ranging by exploiting the strengths of both electrode and coil excitation methods, reducing ambiguity and improving performance in various wellbore geometries and mud types, leading to more precise well intervention and SAGD applications.
Implementation Method 1
inducing a current on a conductive member by transmitting electromagnetic fields by coil antennas positioned in a second wellbore. The induced current in turn may cause the casing to radiate a secondary electromagnetic field
Implementation Method 2
an electrode type source may be used to induce current on the conductive member
Implementation Method 3
The gradient of the magnetic field radiated by the conductive member in addition to the magnetic field itself may be measured
Data Source
AI summary
Systems and methods for utilizing diverse excitation sources in single well electromagnetic ranging. A method may include disposing an electromagnetic ranging tool in a wellbore, wherein the electromagnetic ranging tool may comprise one or more receivers, a coil source and an electrode source; performing a measurement with the one or more receivers of at least one component of a coil-induced magnetic field from the target wellbore to provide a coil measurement, wherein the coil-induced magnetic field may be induced by the coil source; performing a measurement with the one or more receivers of at least component of an electrode-induced electromagnetic field to provide an electrode measurement, wherein the electrode-induced electromagnetic field may be induced by the electrode source; and calculating at least one ranging parameter using, at least in part, the coil measurement and the electrode measurement.