Reverse Engineering-based Evaluation Method For Remaining Life Of Pipe Containing Depression

Pipeline sag is an irrecoverable plastic deformation caused by external forces around the pipe wall.It is very common in the normal pipeline transportation process,but serious sag may affect the normal operation of the pipeline.According to statistics,nearly one third of the oil and gas pipeline accidents occur every year,which are related to sag damage.Various oil and gas pipeline accidents gravely affect the common functioning of the pipeline and the surrounding environment.8762 depressions were found in a 6045 km long pipeline in foreign countries,and hundreds of large and small depressions were found in a domestic pipeline.This paper mainly studies from the following aspects:(1)using 3D scanner to collect and process the data of sunken pipeline,so as to accurately evaluate the residual strength of sunken pipeline and reasonably evaluate the service life of sunken pipeline;(2)on the basis of model establishment,using ABAQUS to carry out finite element analysis of sunken pipeline with 3D modeling,using numerical simulation Simulation method to achieve stress-strain analysis;(3)through three-dimensional scanning technology and geometric deformation detection method to detect sunken pipeline modeling,using effective detection means of sunken pipeline to evaluate the stress-strain situation of sunken area,Make a consult for the future detection technology;(4)In the based of the probity judgment way of oil and gas pipeline,the detection methods of several common sunken defects are studied The residual strength judgment method,through the limited component numerical simulation of the particular factors affecting the pipeline sag,analyzes and calculates the impact of the sag defects on the normal pipeline operation.Through the above research,the following conclusions are obtained:(1)3D scanning technology can effectively restore the sunken pipeline,and can neutrally and effectually estimate the sunken pipeline in engineering application,which can make a consult for future research work;(2)the combination of 3D scanning technology and geometric deformation detection technology can effectively guide the structural design and application of geometric deformation detector,and can also refer to(3)through the finite element analysis of the depressed pipeline,to some extent,the internal pressure of the pipeline relieves the remaining stress in the pipeline depression.