Multicomponent Induction Logging Tool Misalignment Correction

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Solution Overview

Problem

Conventional electromagnetic induction resistivity well logging tools struggle to accurately detect hydrocarbon-bearing zones in multi-layered or laminated reservoirs due to insufficient resolution and sensitivity to vertical conductivity and anisotropy, often dominated by higher conductivity shale layers, and are vulnerable to borehole conditions such as conductive well fluids and wellbore fluid invasion.

Innovation Solution

A method and apparatus for calibrating multicomponent induction logging tools by estimating and correcting for misalignment angles between transmitter and receiver antennas using multi-frequency signals, allowing for improved accuracy in measuring formation resistivity and petrophysical parameters by separating direct field contributions from formation responses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional induction logging tools use coils oriented only along the borehole axis, then the device structure is simple, but the resolution to detect thin layers and sensitivity to vertical conductivity is insufficient

Engineering Contradiction:

Improveresolution to detect thin layersVSAvoidcoil orientation configuration

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces receiver coils oriented transversely to the borehole axis, adding a new spatial dimension to the measurement system. This transverse orientation enables detection of vertical conductivity and anisotropy effects that are invisible to conventional axial-oriented coils, thereby resolving the contradiction between measurement precision and device complexity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The logging tool is segmented into multiple independent coil assemblies - transmitter coils oriented axially and receiver coils oriented transversely. This segmentation allows each coil type to perform its specific function (transmitter detects horizontal conductivity, receiver detects vertical conductivity and anisotropy) while working together to provide comprehensive formation characterization.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If conventional induction logging tools use single-frequency signals, then the device complexity is low, but the ability to separate direct field contributions from formation responses is insufficient

Engineering Contradiction:

Improveaccuracy in separating direct field and formation responseVSAvoidsignal frequency configuration

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs multi-frequency periodic signals to excite the transmitter coils. By using multiple frequencies, the system creates distinct signal patterns that can be mathematically separated into direct field components and formation response components, enabling accurate measurement of formation properties while eliminating the need for complex hardware modifications.

Inventive Principle:

Principle #19Periodic action

3Measurement precision

If transmitter and receiver coils are not perfectly aligned, then the device assembly is easier, but measurement accuracy is compromised due to misalignment errors

Engineering Contradiction:

Improvemeasurement accuracyVSAvoidcoil alignment precision

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent incorporates a feedback mechanism where the system measures the actual response of the coil assembly and compares it against expected values. By analyzing deviations in the measured signals, the system can detect and compensate for misalignment between transmitter and receiver coils, maintaining measurement accuracy without requiring extremely tight manufacturing tolerances.

Inventive Principle:

Principle #23Feedback

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 stability and accuracy of wellbore data acquisition, enabling better detection of hydrocarbon-bearing zones by correcting for misalignment errors and improving sensitivity to vertical conductivity and anisotropy, leading to more reliable interpretation of formation resistivities and petrophysical properties.

Implementation Method 1

One or more transmitter coils are energized by an alternating current. The oscillating magnetic field produced by this arrangement results in the induction of currents in the formations

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

These currents, in turn, contribute to the voltage induced in one or more receiver coils

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS7379818B2Correction of cross-component induction measurements for misalignment using comparison of the XY formation response

Publication Date: 2008.05.27 BAKER HUGHES CO

AI summary

A misalignment angle between the transmitter and receiver antenna of a multicomponent induction logging tool are estimated from quadrature component signals at multiple frequencies. A transmitter antenna having a first axial direction on a logging tool is excited at a plurality of frequencies. Signals responsive to the excitation are received at a receiver antenna having a second axial direction. A direct field between the transmitter antenna and the receiver antenna is obtained by performing multi-frequency focusing of the received signals. The misalignment angle is estimated from the direct field.