Research On Back-up Wrench Device Of Hydraulic Top Drive System Of The Myriameter Continental Scientific Drilling Rig

The development of myriameter continental scientific drilling rig is intended toprovide equipment and technical support for scientific drilling. The all-hydraulic topdrive system is the core of the whole rig, which is also referred to as the “heart” of thetop drive drilling system. The role of the back-up wrench device in the pipe handlingsystem is to fulfill the tripping operation in cooperation with the top drive system.In view of the defect in structural design of the back-up wrench device at present,to adapt to the harsh operating environment and shorten the auxiliary time of drilling,the operating procedures of the back-up wrench have been studied deeply in this paper.Compared with different design prototypes at home and abroad, the design scheme ofa new type of top drive back-up wrench device with big clamping force and safe andreliable operation has been proposed on the basis of previous studies, and the tongdies mechanism of back-up wrench has been optimized and improved.Analyze the composition principle of the clamping mechanism and floatingmechanism of the back-up wrench. The clamping force of the clamping mechanism isrequired to meet the working conditions of on-off, and the floating mechanism shallscrew with the drill pipe threads to realize floating upward and down with the topdrive by floating characteristic of the mechanism, and establish solid model for themechanism using the software Inventor.Use the ADAMS simulation software and AMESim hydraulic simulationsoftware of virtual prototype technology to conduct simulation analysis for theprocesses of clamping and loosening drill pipe of the clamping mechanismrespectively to obtain the kinetic characteristics of position, velocity and accelerationof the hydraulic cylinder piston. Establish simulation model of the hydrauliccomponents, and analyze pressure, flow rate and other working dynamic characteristic parameters of the hydraulic components in the clamping and floating hydraulicsystems to provide theoretical foundation for the mechanism design and hydraulicsystem.Analyze according to the force situations of the tong dies of back-up wrench andthe drill pipe, optimize the design of mechanism parameters of the tong dies with thefinite element software ANSYS, and the change law of its stress value under eachcompound mode of thread angle has been obtained. The optimal structural parametersof the tong dies may be obtained from the analysis results, and the structure and shapeof tong dies in the clamping mechanism shall be designed reasonably to reduce thedestruction probability of drill pipe.The research in this paper will provide reference for the overall design of thedrilling rig, as well as new ideas for the optimization design of the back-up wrenchstructure in future to ensure running reliability of the back-up wrench from thetheoretical analysis, which may minimize accidents in practical application of the drillrig in the future.