Shuang Jing

The fatigue behavior and fatigue reliability analysis of vibroseis baseplates based on fracture mechanics

Due to harsh working conditions and complicated external load, fatigue crack and fracture failure of the vibroseis baseplate usually occur during load cycles. To improve the fatigue resistance and extend the service life of the baseplates, this article studies the fatigue behavior of the baseplate materials and analyzes its fatigue reliability using fracture mechanics. Initially, the baseplate fatigue life is predicted by the crack propagation model based on the Paris’ and Forman’s laws. Three welded characteristic specimens of the baseplate are designed and fatigue is tested under a three-point bending load. The strain value and the crack propagation loading cycles are recorded during the test. Meanwhile, the crack propagation, damage, and fracture region of all the specimens are observed and tracked by scanning electron microscopy, which determines the fatigue damage mechanism of the baseplate. The fatigue reliability and parameter sensitivity analysis have been the subjects of previous research due to the randomness of the fatigue parameters. Finally, the most important random parameters are optimized based on the reliability analysis. As a result, the fatigue life reaches its maximum, and the reliability increases by 1.8%, resulting in a significant improvement in the fatigue resistance ability.

Experimental Research on the Drag Reduction Technology of Nature Gas Pipeline Transportation

As an efficient and environment-friendly energy, natural gas has become an inevitable choice for improving environment, achieving the low carbon economy and the sustainable development all around world. However, flow resistance produced in the course of the gas pipeline transportation caused large loss of transportation energy and brought down the transportation capacity. Therefore, this paper have developed a deep researches on the interaction mechanism between a drag reduction agent (DRA) and the inner surface of natural gas pipeline, the flow pattern improvement regularity about DRA membrane acting on the near-wall region of the pipeline, the relation between the flow pattern improvement and friction resistance, the effect regularity of DRA on the friction coefficient of the pipeline inner surface, and the relation between the alternation of the friction coefficient and the drag reduction. According to all above studies, the fundamental reason for flow resistance of the gas transportation has been found, and the drag reduction mechanism of the gas pipeline transportation has also been hold of. Field test shows that the application of the DRA in the course of the gas pipeline transportation reduced the friction loss by 12%-16.5%, and raised the transfer efficiency by 8%-12%.

Advanced Design for Vibroseis Truck's ROPS and Its Secure and Protective Performance Analyses Based on Dynamics Simulation Research

This research develops a design methodology for the vibroseis truck rollover protective structure (ROPS) and analyses its safety and protective performance with dynamics simulations. A new ROPS with the vertical anti-rolling over property is designed. For the typical field working conditions, we perform the stability study on the vibroseis truck and find its threshold function by using rollover dynamics. With the proposed protection and performance evaluation criteria, we analyse the protection performance of the new and old ROPS with finite element (FE) dynamics simulation. Then, the stress to strain, impact deformation, impact acceleration and interior energy distribution law are obtained during the process of the truck rolling over. The effect of the structure on its protective performance is also found. These analyses result in an optimal design of ROPS. The results will improve the safety of vibroseis trucks and then enhance the technology of oil and gas exploration equipment.

Failure Analysis of Pipe's Repaired Mouth and its Improvement Measures and Suggestions

With the increment of the oil-field extract strength and the pipeline infusion load, the pipeline damage had become more serious and the effective use of cycle got shorter. Pipeline damage mainly appeared pipeline corrosion. The pipeline corrosion mainly occured in the place of pipes repaired mouth and mending of blemishes. In this paper, through failure analysis of the pipes Heat Shrinkable Wraparound Sleeve (HHWS) repaired mouth, we found the failure modes and failure causes of the repaired mouth of the existing pipeline and new pipeline, and grasped the failure mechanism. Then, improvement measures and suggestions were proposed to prevent failure, ensure safety, improve quality of the pipes repaired mouth, slow or prevent pipeline corrosion and extend pipeline life.