Threaded Tubular Coupling Quality Checks via Torque-Turn Shape Analysis

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Solution Overview

Problem

Current methods for evaluating the quality of connections between tubular components with threaded portions are inadequate, leading to a high probability of unsatisfactory evaluations and potential safety and environmental risks, as they rely on limited parameters and require additional human supervision, which can slow down operations.

Innovation Solution

A method that involves obtaining a torque/turns curve during connection, comparing its parameters with reference curves in a database using an algorithm driven by automatic learning, and evaluating the connection quality based on shape and linearity analysis, including Principal Component Analysis and data partitioning techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional methods with limited parameters are used for evaluating connection quality, then the evaluation process is simple, but the reliability of the evaluation is low leading to high probability of unsatisfactory evaluations

Engineering Contradiction:
Improveconnection quality evaluation reliabilityVSAvoidevaluation method complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The evaluation method is segmented into multiple distinct phases: initial engagement phase, sealing phase, and final tightening phase. Each phase has specific parameter ranges and evaluation criteria. This segmentation allows for more reliable evaluation by assessing different aspects of the connection process separately, rather than using a single limited parameter set.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention adds multiple dimensions to the evaluation by considering both torque values and number of turns simultaneously, creating a two-dimensional evaluation space. Furthermore, it introduces temporal dimension by evaluating different phases of the tightening process separately. This multi-dimensional approach significantly improves evaluation reliability compared to conventional single-parameter methods.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If additional human supervision is added to verify connection quality, then the evaluation accuracy improves, but the productivity decreases due to slower operations

Engineering Contradiction:
Improveconnection quality assessment accuracyVSAvoidassembly operation speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The evaluation system performs self-assessment by automatically analyzing the torque/turns curve data and comparing it against predefined phase criteria. The system independently determines whether each phase was properly executed and provides an overall connection quality assessment without requiring human intervention, thus maintaining high accuracy while preserving productivity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system provides immediate feedback on connection quality by continuously monitoring torque and turns during the tightening process and comparing real-time data against the expected phase characteristics. This automated feedback loop ensures accurate assessment while maintaining fast operation speed, eliminating the need for slow manual verification.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If more parameters are considered in the evaluation, then the measurement precision improves, but the device complexity increases

Engineering Contradiction:
Improveconnection evaluation precisionVSAvoidevaluation system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Different parameters are applied locally to different phases of the tightening process. For example, the initial engagement phase focuses on specific torque ranges, while the sealing phase emphasizes turn counts and torque stability. This localized parameter application improves measurement precision for each specific phase without requiring all parameters to be considered simultaneously, thus managing system complexity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3774171B1Method for assessing the quality of the coupling of two tubular components
Publication Date: 2022.10.19 VALLOUREC MANNESMANN OIL & GAS FRANCE
  • EP3774171B1 patent drawingFigure 1A~1C
  • EP3774171B1 patent drawingFigure 2~3
  • EP3774171B1 patent drawingFigure 4~5

AI summary

The invention relates to a method for coupling a first tubular component (1) including a threaded portion (3) with a second tubular component (2) including a threaded portion (4), which comprises: engaging (11) the first tubular component (1) on the second tubular component (2); rotating (12) the first tubular component (1) relative to the second tubular component (2) in order to screw the threaded portions (3, 4) together; obtaining (13) a set of points constituting a curve that represents the torque applied during the screwing of the first tubular component (1) until an end position as a function of the number of turns performed by the first tubular component (1) relative to the second tubular component (2); comparing (20) one or more parameters of the curve obtained with one or more reference curve(s) of a database in which each reference curve is associated with an assessment of the quality of the coupling of first and second reference tubular components; and assessing (21) the quality of the coupling of the first and second tubular components (1, 2) according to the step of comparing (20) the curve obtained with the reference curves. Moreover, the comparing step (20) includes comparing the shape of at least one portion of the curve obtained.