Design On The Virtual Prototype Of The Workover Rig’s Operation Platform And Analysis On The Related Parts

Steam-flooding high-temperature snubbing, an important technique to increase the yield of heavy oil deep in oil field, has now been highly valued for oil exploitation.Workover rig is a petroleum machine that can work under complex conditions. During the whole working process, the machine tends to become fatigue due to the dynamic load generated in each system. To ensure both the safety and the reliability of the system, damage assessment and lifetime analysis shall be conducted by using finite element software and based on fatigue theory.In the study, the virtual prototype simulation technique is used to build the parameterized models of the working platform system, the pushing pipe system, the mechanical arm running and pulling system and the supporting truss. And the software CAE is used to make fatigue analysis.The detailed analysis is as follows:(1) The effect of the sine-approximate load and the white noise load on the working platform is investigated by analyzing the actual conditions of the platform. On the basis of the classical fatigue theory, methods for stress calculation, stress combination as well as for mean stress correction are determined, and the concept of survival rate is proposed. The software CAE is used to analyze the fatigue damage.(2) Firstly, based on the operating features of the pushing pipe system, the classical mechanics theory is used to build the mathematical model as well as to establish the driving equation of the hydraulic cylinder, which are used for CAE analysis. Secondly, the rigid-flexible coupling of the system is modeled, and the transient dynamics is used to investigate the stress and deformation of the system. Next, to ensure the reliability of the system, the time-domain fatigue is analyzed by using the software nCode, with considering the results of the dynamics. Finally, the model of the clamping mechanical arm is built for static analysis.(3) To ensure that the pushing pipe transfer of the system can be achieved completely, the reliability of the mechanical arm running and pulling system is researched. Firstly, the mathematical model of the running and pulling system is set up, and the software ADAMS is used to figure out the characteristic curve of the system. Secondly, workbench is used for transient dynamic analysis, to make clear of the relation between safety coefficient and “stress-time” of the system. Finally, the software nCode is employed to make the time-step stress fatigue analysis, so to determine the reliability of the system.(4) The reliability of the supporting truss was studied. By analyzing the harmonic response of the truss, the curves of the beam nodes’ deformation and the acceleration, which are changing with frequency, were obtained. The random vibration excitation is set in the software nCode, to make a precise vibration fatigue analysis of the truss.