Engineering Commons^™

Application Of Wavelet Analysis And Random Field In Integrity Management Of Pipelines Containing Dents And Corrosions, Junxiong Lin

Electronic Thesis and Dissertation Repository

Metal loss corrosions and dents are two major threats to the integrity of oil and natural gas pipelines. In the pipeline industry, the Fitness-For-Service (FFS) assessment is commonly employed for pipelines containing these defects. However, FFS assessment usually assumes that a defect has a simple shape, and such a simplification may significantly affect the accuracy of the assessment. Therefore, retaining the actual shapes of defects and incorporating them into the FFS assessment can improve assessment accuracy. The main objective of the present thesis is to extract key information about the sizes, directions, and shapes of corrosions and dents from the …

Burst Capacity Evaluation Of Corroded Pipelines Under Internal Pressure And Internal Pressure Combined With Longitudinal Compression, Shulong Zhang

Electronic Thesis and Dissertation Repository

Central to the design and integrity assessment of oil and gas transmission pipelines is to accurately evaluate their pressure containment capacities, i.e. burst capacities. Corrosion defects threaten the structural integrity of pipelines as they cause thinning of the pipe wall and therefore reduce the burst capacity. Corroded in-service pipelines may be subjected to longitudinal compression resulting from, for example, ground movement or formation of free spans, in addition to internal pressures. The main objective of the research reported in this thesis is to facilitate Fitness-For-Service (FFS) assessment of corroded pipelines.

The first study investigates the conservatism associated with the rectangular …

Numerical Studies For Improving Fracture Toughness Resistance Curve Testing Using Single-Edge (Notched) Tension Specimens, Yifan Huang

Electronic Thesis and Dissertation Repository

The fracture toughness resistance curve, i.e. the J-integral resistance curve (J-R curve) or the crack tip opening displacement resistance (CTOD-R) curves, is widely used in the integrity assessment and strain-based design of energy pipelines with respect to planar defects (i.e. cracks). This thesis deals with issues related to the experimental determination of the J(CTOD)-R curves using the newly-developed single-edge (notched) tension (SE(T)) specimens. In the first study, the plastic geometry factor, i.e. the η_pl factor, used to evaluate J in a J-R curve test based on …

Development Of Probabilistic Corrosion Growth Models With Applications In Integrity Management Of Pipelines, Shenwei Zhang

Electronic Thesis and Dissertation Repository

Metal-loss corrosion is a major threat to the structural integrity and safe operation of underground oil and gas pipelines worldwide. The reliability-based corrosion management program has been increasingly used in the pipeline industry, which typically includes three tasks, namely periodic high-resolution inline inspections (ILIs) to detect and size corrosion defects on a given pipeline, engineering critical assessment of the corrosion defects reported by the inspection tool and mitigation of defects. This study addresses the core involved in the reliability-based corrosion management program. First, the stochastic process in conjunction with the hierarchical Bayesian methodology is used to characterize the growth of …