Rotating Annulus Test for Realistic Drill Cuttings Dispersion

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Solution Overview

Problem

Existing dispersion tests for drilling fluid additives do not accurately model the flow conditions in wellbores, leading to inaccurate evaluation of the effectiveness of additives in reducing clay dispersion, which affects drilling operations by increasing fluid density and viscosity.

Innovation Solution

A test apparatus and method using independently rotating inner and outer cylinders to simulate wellbore flow conditions, including axial shear and Taylor vortices, to evaluate the dispersion of drill cuttings in drilling fluids.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional hot rolling dispersion testing is used, then the testing process is simple, but the test results do not accurately reflect wellbore flow conditions

Engineering Contradiction:
Improveaccuracy of dispersion test resultsVSAvoidcomplexity of test apparatus
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a laboratory-scale model that copies the essential flow characteristics of wellbore conditions. By using a transparent tube to simulate the annular space between drill string and wellbore, and circulating drilling fluid through it, the apparatus replicates the actual flow environment where cuttings dispersion occurs, enabling accurate testing without needing actual wellbore conditions

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The transparent test tube acts as an intermediary medium between the laboratory testing environment and the actual wellbore conditions. It provides a controlled interface where drilling fluid can be circulated under conditions that mimic wellbore flow, allowing indirect observation and measurement of cuttings dispersion behavior that would otherwise be inaccessible

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If hot rolling at high temperature is applied, then mixing intensity is increased, but the flow conditions do not represent actual wellbore annulus flow

Engineering Contradiction:
Improvemixing intensityVSAvoidrepresentativeness of flow conditions
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent changes the flow regime parameters to match wellbore conditions. Instead of using high-intensity mechanical mixing or hot rolling, the apparatus uses controlled fluid circulation at temperatures and flow rates that replicate actual wellbore annulus conditions, achieving realistic cuttings dispersion behavior without excessive energy input or temperature elevation

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If simple mixing methods are used, then the testing procedure is easy to perform, but clay dispersion is not effectively inhibited or evaluated

Engineering Contradiction:
Improveease of dispersion testingVSAvoidevaluation accuracy of additive effectiveness
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The apparatus enables self-contained testing where the circulating drilling fluid automatically performs the mixing and dispersion evaluation functions. The system uses the fluid's own circulation to transport cuttings and demonstrate dispersion effects, eliminating the need for external mixing devices or complex operational procedures while maintaining accurate evaluation capability

Inventive Principle:
Principle #25Self-service

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 simulates downhole flow conditions, enabling effective evaluation of drilling fluid additives by assessing drill cutting dispersion and stability under realistic drilling conditions.

Implementation Method 1

The inner and outer cylinders are configured to rotate independently with respect to one another... to simulate desired flow conditions in the annular volume... including axial shear and Taylor vortices

Methodology Applied
Scientific EffectTaylor vortices:

Data Source

PatentEP4660627A1Apparatus and method for testing a drill cuttings dispersion
Publication Date: 2025.12.10 SERVICES PETROLIERS SCHLUMBERGER SA
  • EP4660627A1 patent drawingFigure 1
  • EP4660627A1 patent drawingFigure 2A~3B
  • EP4660627A1 patent drawingFigure 4~6

AI summary

A method for evaluating a multiphase fluid includes adding the multiphase fluid to an annular volume of a test apparatus, the test apparatus including an inner cylinder deployed in an outer cylinder thereby defining the annular volume. The inner and outer cylinders are configured to rotate independently with respect to one another. The method further includes rotating at least one of the inner and outer cylinders after adding the multiphase fluid to the annular volume to simulate desired flow conditions in the annular volume. The method still further includes removing the multiphase fluid from the annular volume after rotating and evaluating at least one physical property of the removed multiphase fluid.