Anisotropic Casing Evaluation Using AL and SHA Acoustic Waves

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Solution Overview

Problem

Current methodologies for evaluating annular solids and fluids behind casings in the natural gas industry assume isotropic properties, which is inadequate for nonconformal, anisotropic casings, particularly those with high chromium content, leading to difficulties in differentiating between solids and fluids and assessing cement quality.

Innovation Solution

A system and method utilizing a combination of asymmetric lamb (AL) and shear horizontal acoustic (SHA) waves to evaluate the quality of sheathing behind anisotropic casings, where AL waves have particle displacement normal to the casing surface and SHA waves rotate this displacement 90°, enabling detection of both solid and fluid aspects of cementitious materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If isotropic casing evaluation methodologies are used, then the evaluation process is simple, but the accuracy of solids and fluids differentiation deteriorates for anisotropic casings

Engineering Contradiction:

Improveevaluation methodology complexityVSAvoidsolids and fluids differentiation accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent changes the physical parameters of wave propagation by using multiple wave modes (ASH, AL, SHA) with different particle displacement characteristics. This allows the evaluation system to adapt to anisotropic casing properties by selecting and combining wave modes that provide accurate differentiation between solids and fluids behind anisotropic casings, resolving the contradiction between method simplicity and measurement accuracy.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If conventional wave evaluation methods are used, then the equipment configuration is simple, but the capability to evaluate anisotropic casings deteriorates

Engineering Contradiction:

Improveequipment configurationVSAvoidanisotropic casing evaluation capability

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements a multi-functional wave generation system that can produce multiple wave modes (ASH, AL, SHA) from a single tool configuration. This universal approach allows the same equipment to evaluate both isotropic and anisotropic casings by appropriately selecting and combining wave modes, thereby achieving high adaptability without proportionally increasing device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent uses a composite approach by combining multiple wave modes with different propagation characteristics to evaluate anisotropic casings. The combination of SH-type and Lamb-type waves creates a composite evaluation methodology that overcomes the limitations of individual wave modes when dealing with anisotropic materials, enabling accurate solids and fluids differentiation.

Inventive Principle:

Principle #40Composite materials

3Ease of operation

If single wave mode evaluation is used, then the measurement process is straightforward, but the ability to differentiate solids and fluids behind anisotropic casings deteriorates

Engineering Contradiction:

Improvemeasurement process simplicityVSAvoidcement quality assessment accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent merges multiple wave modes (ASH, AL, SHA) into a unified evaluation process. By combining wave modes with different particle displacement orientations and propagation characteristics, the system achieves accurate solids and fluids differentiation behind anisotropic casings while maintaining operational simplicity through integrated data processing and analysis.

Inventive Principle:

Principle #5Merging (Combining)

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 effectively differentiates between solids and fluids and determines the quality of cementitious materials behind anisotropic casings, providing baseline values for free pipe conditions to interpret cement quality, even in high chromium content casings, overcoming limitations of existing technologies.

Implementation Method 1

One or more wave generators provide at least asymmetric lamb (AL) waves through a casing having an anisotropic property in a first mode of the system, and provide at least shear horizontal acoustic (SHA) waves through the casing in a second mode

Methodology Applied

Scientific EffectAcoustic wave propagation: Sound

Data Source

PatentUS12180824B2Anisotropic casing solids and fluids identification system and method using shear and flexural acoustic waves

Publication Date: 2024.12.31 BAKER HUGHES OILFIELD OPERATIONS LLC

AI summary

A system for evaluation of a sheathing behind a casing of a wellbore. One or more wave generators provide at least asymmetric lamb (AL) waves through a casing having an anisotropic property in a first mode of the system, and provide at least shear horizontal acoustic (SHA) waves through the casing in a second mode that is concurrent with the first mode. A receiver receives indications associated with the SHA waves and the AL waves. At least one processor determines a quality of the sheathing behind the casing based in part on the indications associated with the SHA waves and the AL waves.