Whole-local mechanical analysis and application of long-distance oil and gas pipelines considering dents caused by loading

Area of Science:

• Engineering Mechanics
• Materials Science
• Petroleum Engineering

Background:

• Dental defects are common in long-distance pipelines, causing plastic deformation and compromising structural integrity.
• Understanding the mechanical behavior of dented pipelines is crucial for operational safety and longevity.

Purpose of the Study:

• To analyze the mechanical behavior of pipeline indentations using a combined whole-local calculation method.
• To investigate the influence of concentrated, bending, and internal pressure loads on dent deformation in oil and gas pipelines.

Main Methods:

• A novel method combining whole and local calculations was employed.
• Simulations were validated against measured indentation depths.
• Analysis focused on Mises stress, equivalent plastic strain, and indentation depth under various load conditions.

Main Results:

• Simulated and measured indentation depths showed good agreement.
• Maximum stress and strain occurred at pipeline-support contact edges.
• Pipeline stress decreased then increased with internal pressure, reaching a minimum at 4 MPa.

Conclusions:

• The combined whole-local method accurately predicts pipeline dent behavior.
• Contact edges are the most critical areas for pipeline integrity.
• Load conditions significantly influence dent evolution, with high loads exacerbating deformation.