Jialin Tian

The Vibration Characteristics Analysis of Pipeline Under the Action of Gas Pressure Pulsation Coupling

In order to research the pipeline vibration and prevent the fatigue failure of pipeline, the calculation model and methods for vibration characteristics analysis of pipeline under the action of the gas pressure pulsation and pipeline coupling are presented in this paper. According to the pipeline structure, the pipeline model with different pipe diameters is established. Based on the model and combined with the structure parameters of pipeline, the calculation methods of gas column natural frequency, gas pressure pulsation, and exciting force are built. By these ways, the relationships between the gas column natural frequency and orders, the gas pressure pulsation and orders, and the exciting force and aspect ratio are acquired. Besides, the variable relationships of vibration displacement and velocity of pipeline can be obtained. Comparing the calculated results with the field test values, the calculated results are in agreement with the test values, and the correctness of the calculation model and method is verified. The results show that taking the pressure pulsating and pipe coupling effect account into the vibration analysis of different pipe diameters, which can truly reflect the vibration characteristics of pipeline and possess important reference value for preventing fatigue failure and reducing the vibration of the pipeline.

The wear analysis model and rock-breaking mechanism of a new embedded polycrystalline diamond compact

Polycrystalline diamond layer peel-off is a hot topic in oil and gas drilling engineering. When an integrated polycrystalline diamond compact cutter suffers overload, there is a rapid decline in its rock-breaking performance and drilling rate of penetration. To modify the comprehensive performance of polycrystalline diamond compact, we innovatively propose a new embedded polycrystalline diamond compact. According to geometric analysis theory combined with the linear combination rule, the three typical embedded design schemes – the imitation palm-shaped, imitation Z-shaped and ring-embedded designs – are discussed. The influences of the number, size, location and combination of the embedded polycrystalline diamond layer on the polycrystalline diamond compact wear mechanism and rock-breaking performance are analysed. The results show that the embedded element and carbide matrix are combined by brazing welding, which not only exerts high abrasion resistance on the polycrystalline diamond layer but also combines with the good impact performance of carbide matrix. Compared with ordinary polycrystalline diamond compact, the intake amount of a single-embedded polycrystalline diamond compact is smaller, and it wears more evenly during the rock-breaking process. Comparing the results from before and after drilling, it effectively prevents the ordinary polycrystalline diamond compact from easily peeling off when suffering overload. The unique wear analysis model can be applied to other types of polycrystalline diamond compact by adjusting the embedding method. The research conclusions provide useful insights into the study of the polycrystalline diamond compact wear mechanism and rock-breaking performance.

The Wear Analysis Model of Drill Bit Cutting Element with Torsion Vibration

Due to some deficiencies in the existing researches of cutting element wear of polycrystalline diamond compact (PDC) drill bit and to reduce the wear rate of cutting element of PDC bit, accurately illustrate the effect of tooth-distributing angle on cutting element, and improve the service life of PDC drill bit, we use the geometry knowledge of PDC drill bit and establish the torsion vibration model of PDC drill bit, solve and analyze the model, and at last analyze the effect of tooth-distributing angle on the rule of cutting element wear by using the wear theory.

Vibration characteristics analysis and experimental study of new drilling oscillator

In new drilling conditions such as extended reach drilling or long horizontal well, to avoid large friction between drill string and wellbore or weigh on bit decreasing, a new drilling vibration tool (called antifriction oscillator) is presented in this article. For discussing its working mechanism and performance, first, the kinematics models are established based on the structure design parameter, and then the horizontal vibration models are presented according to drilling conditions. With the numerical example results, it can be concluded that the frequency of the flow area between the static and dynamic valve plates is proportional to the flow rate. Moreover, with the increasing size of static valve plate, the flow area is increasing while the total axial force is decreasing. Furthermore, according to the experiment test results with static valve plate hole diameter 35.56 mm, the vibration results are discussed by comparing with numerical example results, and it can verify the analysis models’ rationality and the calculation formulas’ correctness. The research results provide basis for theoretical research and field applications of drilling oscillator. Furthermore, by changing corresponding parameters, the research methods and models can also provide reference for the design of new methods or tools of drilling friction reduction or rate of penetration increasing technologies.

Study on Lateral Vibration Characteristics of a Drill String with Transverse Inertia Effect

Drill string vibration is an important factor to influence the normal operation of drilling string system, and lateral vibration is the most complex and most severe vibration form. In order to further understand the lateral vibration characteristics of modes and dynamic for drill string, effectively prevent drill string failure, and improve the service life of drill string, a lateral vibration model of a drill string with transverse inertia effect is established. Then the variation trend of lateral vibration natural frequency of drill string under different conditions is analyzed. The analysis results show that under the influence of transverse inertial effect, the lateral vibration natural frequency of drill string is higher than that without considering the transverse inertia effect. At the same time, the natural frequency gradually decreases with the increase of drill string length; the natural frequency starts to increase and then decrease with the increase of borehole diameter, and the natural frequency gradually increases with the increase of the ratio of external and internal diameter of drill string.