Borehole Bond Inspection Using Nuclear Signals Under Tool Eccentricity

Solution Overview

Problem

Existing methods for detecting flaws in bonding layers within boreholes, such as cement layers, are challenged by variations in nuclear signal data due to the rotation and de-centered position of inspection tools, making it difficult to differentiate between signal variations caused by flaws and those caused by tool eccentricity.

Innovation Solution

A system and method that utilizes a sensor device to detect nuclear signals, processes the data to remove variations due to tool rotation by comparing it to a reference curve, and analyzes the processed data to identify flaws in the bonding layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If nuclear signal data is collected during sensor device rotation to detect bonding layer flaws, then flaw detection capability is improved, but signal variations due to tool eccentricity and rotation make accurate differentiation difficult

Engineering Contradiction:

Improveflaw detection precisionVSAvoidsignal variation differentiation difficulty

Core Design Contradiction:

Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies preliminary action by acquiring reference nuclear signal data before the actual inspection. This reference data represents the expected signal characteristics when the tool is properly centered, allowing subsequent comparison to identify deviations caused by eccentricity versus actual bonding layer flaws

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by continuously comparing the nuclear signal data collected during inspection against the pre-acquired reference data. This feedback mechanism enables real-time differentiation between signal variations caused by tool eccentricity (which should match reference patterns) and actual flaws (which will deviate from reference patterns)

Inventive Principle:

Principle #23Feedback

2Productivity

If the sensor device is rotated through multiple azimuthal positions to inspect the bonding layer, then comprehensive flaw detection is improved, but de-centered rotation introduces spurious signal variations

Engineering Contradiction:

Improveinspection comprehensive coverageVSAvoidsignal accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by acquiring reference nuclear signal data before the actual inspection. This reference data represents the expected signal characteristics when the tool is properly centered, allowing subsequent comparison to identify deviations caused by eccentricity versus actual bonding layer flaws

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by continuously comparing the nuclear signal data collected during inspection against the pre-acquired reference data. This feedback mechanism enables real-time differentiation between signal variations caused by tool eccentricity (which should match reference patterns) and actual flaws (which will deviate from reference patterns)

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

Accurately detects and locates flaws in bonding layers by removing background variations, enhancing the ability to differentiate between signal fluctuations caused by tool eccentricity and actual flaws.

Implementation Method 1

detect nuclear signals from the bonding layer

Methodology Applied

Scientific EffectNuclear signals: Radioactive Decay

Data Source

PatentUS12534996B2Detection of flaws based on processing of nuclear signals

Publication Date: 2026.01.27 BAKER HUGHES OILFIELD OPERATIONS LLC

AI summary

A system for inspecting a bond includes a sensor device configured to be deployed in a borehole proximate to a first tubular downhole component, the sensor device configured to direct measurement signals to a bonding layer and detect nuclear signals from the bonding layer during rotation of the sensor device, the bonding layer configured to secure the first tubular downhole component to a borehole wall or another tubular component. The system also includes a processor configured to process nuclear signal data to remove variations in the nuclear signal data due to rotation of the sensor device when the sensor device is de-centered relative to the first tubular downhole component, the processing resulting in a set of processed data, and analyze the processed data to detect one or more flaws in the bonding layer.