| Workover operation is important in the oil and gas production. As most oilfileds in our country have entered into the later period, workover tasks become more and more heavy. But the traditional operation mode with lower level mechanical automation is still used in most cases, especially in common maintance. Workover wokers work in high labor intensity and poor safety, and the working environment is also very poor. In order to let the workover wokers far away from wellhead, reduce labor intensity, increase the operational efficiency and realize safe operation, it is a general trend to design and develop new type of workover mechanical system to satisfy actual situations.In this paper, based on full investigation and analysis of the progress of workover operation and domestic and aboard workover and drilling mechanical automation technology, a system scheme that can better realize draging pipe, feeding pipe, pushing pipe, grasping pipe, centralizing pipe, make-up and break-out pipe by mechanical automation is put forward. This system mainly consists of integrated hydraulic tong system and hoisting system. The paper is mainly focused on the research and analysis about modeling and simulation of hoisting system and make-up and break-out system.The paper finished overall design of the new type workover mechanical system, and the detailed and reasonable design of all components of the system are given. The 3D models of the system are created in SolidWorks software.According to multiple rigid body kinematics and dynamics, research and analysis of modeling ring-elevator system are made. The kinematics equations of elevator including position, velocity and acceleration are derived. The inverse dynamics analysis is also made for the ring-elevator system. Based on ADAMS, the mechanical-hydraulic simulation of the swinging out manipulator, its pushing oil pipe and the swinging out rings-elevator are made respectively. Various dynamic characteristics of the composition parts are obtained, and hydraulic system parameters are founded, which is beneficial to the work of composition parts and provides theoretical basis for the selection of actual hydraulic component. The mechanical-hydraulic simulations, including the process of contact-impact between oil pipe and centralizing manipulator that in the state of swinging out completely and the state of the oil pipe swinging to the wellhead are simulated. The influence of the materials of supporting part of centralizing manipulator, the weight of oil pipe and the open size of throttle valve in the process of contact-impact are also analyzed.The properties of workover mechanical system lie in good structure design and the ability of quick and accurate response, and the system coupling relationship constrains its performance. That is, it decides whether the performance of the whole system is good or not. In this paper, bond graph and modular approach are used to establish oil pipe make-up and break-out system. The system is simplified as a valve controlled asymmetrical cylinder, valve controlled motor, quantitative pump-relief valve and so on. Based on physics, fluid mechanics, and dynamics, the mathematical model and transfer function are obtained, which is the theoretical foundation of the system simulation. On this basis, AMESim is used to modeling oil pipe make-up and break-out pipe system, then making the simulation experiments of variable parameters. These studies provide theoretical basis for evaluating the performance of oil pipe make-up and break-out system.The paper introduces experimental prototype and field test at last. Contrast of test results and simulation results is made, and the error between the test data and the simulated data are analyzed. The correctness of theoretical models of the system is verified, and simulation techniques are feasible to study system dynamic characteristics. The simulation results are helpful to understand the working characteristics of the system thoroughly and comprehensively.
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