External Acoustic Sensors for Annulus Fluid Detection

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Solution Overview

Problem

Existing acoustic systems for monitoring wellbore casing placement and cementation processes are isolated from the annular regions between the casing and formation, limiting their ability to detect conditions during or after cementation.

Innovation Solution

Acoustic sensors mounted on the outside of the casing transmit and receive acoustic signals to determine casing placement and monitor fluids in the annulus, using electrical circuitry and processors to analyze two-way travel times and amplitudes to estimate borehole shape and fluid properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If acoustic systems are mounted inside the casing, then the system structure is simple and easy to install, but the system is isolated from annular regions and cannot detect conditions during or after cementation processes

Engineering Contradiction:

Improvedetection capabilityVSAvoidsystem configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent inverts the conventional mounting location of acoustic systems from inside the casing to outside the casing. This inversion allows the acoustic sensors to directly contact the annular region between the casing and formation, enabling detection of cementation conditions and annular fluids while maintaining system simplicity through external mounting on the casing surface.

Inventive Principle:

Principle #13The other way round (Inversion)

2Measurement precision

If acoustic systems are mounted outside the casing, then detection capability in annular regions is improved, but system complexity increases

Engineering Contradiction:

Improvecasing placement determinationVSAvoidelectrical circuitry and processors

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements multi-functionality by using the same external acoustic sensors to perform multiple tasks: determining casing placement, identifying annular fluids, and monitoring cementation processes. This universal approach improves measurement precision across different parameters while avoiding the need for separate specialized systems, thereby managing overall device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Loss of information

If acoustic signals are used to map casing placement and monitor annular fluids, then well integrity understanding is improved, but the system cannot detect conditions during cementation processes

Engineering Contradiction:

Improveinformation about annular conditionsVSAvoidannular fluid detection

Core Design Contradiction:

Loss of informationVSDifficulty of detecting and measuring

Solution Approach 1:

The patent uses acoustic signals as an intermediary to bridge the gap between the external monitoring system and the annular region conditions. The acoustic waves penetrate through the casing and annular materials to carry information about casing placement, fluid presence, and cementation status, enabling detection of conditions during cementation processes without direct physical contact with the annular space.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Enables accurate determination of casing placement and fluid identification within the annulus, facilitating well integrity monitoring and cementation process management.

Implementation Method 1

Acoustic sensors mounted on the outside of the casing transmit and receive acoustic signals to determine casing placement and monitor fluids in the annulus

Methodology Applied

Scientific EffectAcoustic wave propagation: Sound

Implementation Method 2

acoustic sensors to emit acoustic signals and receive reflections of the acoustic signals from a boundary between materials

Methodology Applied

Scientific EffectAcoustic reflection: Reflection

Implementation Method 3

generate distance measurements representative of distances between corresponding acoustic sensors and points on the borehole wall based on the two-way travel times

Methodology Applied

Scientific EffectTime of flight: Time of Flight

Data Source

PatentUS10352152B2Acoustic calipering and analysis of annulus materials

Publication Date: 2019.07.16 HALLIBURTON ENERGY SERVICES INC

AI summary

An apparatus and method may operate to mount acoustic sensors, azimuthally offset from each other, to the exterior of a casing. After the casing and acoustic sensors are in the borehole, signals are provided to the acoustic sensors to cause the acoustic sensors to emit acoustic signals into the annulus around the casing. The method further includes detecting reflected compression waves, shear waves or a combination or conversion thereof at the acoustic sensors to generate a set of two]way travel times of the acoustic signals. The method can further include generating distance measurements of a distance between corresponding acoustic sensors and points on the borehole wall based on the two]way travel times, to determine a position of the casing within the borehole. The method can further include identifying fluids based on the two]way travel times. Additional apparatus, systems, and methods are disclosed.