Ultrasonic Echo Amplitude Correction for Eccentering

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Ultrasonic pulse-echo measurements in oil and gas exploration are hindered by the attenuative effects of drilling mud and tool eccentricity, which cause significant skewing of wellbore surface data and mask valuable geological and geomechanical information, with existing enhancement techniques like histogram equalization failing to effectively correct for contrast variations and eccentering effects.

Innovation Solution

A method and system that collect and process ultrasonic pulse-echo data from downhole tools, extracting echo envelope amplitude, azimuth, and location information to assess sensitivity to geometric and spatial characteristics, correcting echo envelope amplitudes for eccentering effects, and generating a visual representation of the corrected data to enhance contrast resolution and retain detail of subterranean formations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If histogram equalization and dynamic correction are used to correct eccentering effects, then contrast enhancement is improved, but the ability to account for formation features and dynamic tool motion artifacts deteriorates

Engineering Contradiction:

Improvecontrast enhancementVSAvoidformation features and dynamic tool motion artifacts

Core Design Contradiction:

Illumination intensityVSLoss of information

Solution Approach 1:

The patent applies parameter changes by using a sinusoidal correction function with adjustable amplitude and frequency parameters to model eccentering effects. This allows the correction to adapt to different tool positions and wellbore conditions while preserving formation-specific amplitude variations that histogram equalization would incorrectly treat as eccentering artifacts.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If ultrasonic pulse-echo measurements are performed through drilling mud, then wellbore and formation evaluation is enabled, but signal attenuation increases

Engineering Contradiction:

Improvewellbore and formation evaluation capabilityVSAvoidacoustic signal attenuation

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces direct mechanical/acoustic measurement through the attenuative drilling mud with an indirect correction approach. By measuring echo amplitudes at multiple tool positions and using sinusoidal regression to separate eccentering effects from formation properties, the system compensates for mud attenuation without requiring direct high-fidelity signal transmission through the mud column.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If downhole tool eccentering occurs, then tool rotation and movement along wellbore axis is possible, but wellbore surface data skewing increases

Engineering Contradiction:

Improvetool rotation and movement capabilityVSAvoidwellbore surface data accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent implements feedback by continuously monitoring echo amplitude variations during tool rotation and movement, then using sinusoidal regression analysis to determine the eccentering pattern. This feedback information is used to correct the wellbore surface data in real-time, compensating for the data skewing caused by tool eccentering while maintaining the operational flexibility of tool rotation and movement.

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

The solution effectively corrects for eccentering effects and enhances contrast resolution in ultrasonic pulse-echo measurements, providing accurate and detailed images of wellbore and subterranean formations, even in acoustically attenuative drilling mud environments, thereby improving the interpretation of geological and geomechanical data.

Implementation Method 1

Ultrasonic pulse-echo measurements have been used for oil and gas exploration and production. Ultrasonic pulse-echo imaging is a technique to interrogate a wellbore surface for acoustic reflectivity and geometry

Methodology Applied

Scientific EffectUltrasonic pulse-echo: Ultrasound

Implementation Method 2

Downhole acoustic tools may be utilized, during or after drilling of a wellbore, in order to evaluate various aspects of the wellbore and/or of subterranean formations intersecting the wellbore surface, such as by evaluating amplitudes of ultrasonic pulses traveling from the transducer to the wellbore surface and echoes refracted to a detector corresponding to the transducer

Methodology Applied

Scientific EffectAcoustic reflection: Reflection

Implementation Method 3

drilling muds can be quite attenuative to acoustic pulses

Methodology Applied

Scientific EffectAcoustic attenuation: Absorption (EM radiation)

Data Source

PatentUS11022711B2Correcting eccentering effect in pulse-echo imaging

Publication Date: 2021.06.01 SCHLUMBERGER TECH CORP

AI summary

Methods for correcting eccentering effects on echoes detected from ultrasonic pulses emitted by a transducer of a downhole tool. Echo envelope amplitude, azimuth, and location for each echo is utilized to assess echo amplitude sensitivity to geometric and spatial characteristics of the downhole tool within the wellbore. Echo envelope amplitudes are corrected for eccentering effects based on the assessed sensitivity. A visual representation of the corrected echo envelope amplitudes is the generated. Also disclosed herein are tangible, non-transient, computer-readable media comprising instructions executable by a processor to carry out the methods, as well as systems including downhole tools and processing devices operable to carry out the methods.