A Long-distance Pushing and Rotary Equipment for Natural Gas Hydrate Pressure Core

Due to the special occurrence condition of natural gas hydrate, it is of great significance for researchers to know natural gas hydrate under in-situ pressure and temperature. This paper mainly introduces a long-distance pushing and rotating Equipment for natural gas hydrate pressure core, which is an important component of the Analysis and Transfer System of Seafloor Natural Gas Hydrate Pressure Core. According to the requirements of working function, this paper mainly presents two kinds of technical scheme which can apply to transferring pressure core tube, including the structure of telescopic rod and the structure of screw and spline shaft. First of all, the working process of two kinds of technical scheme are described in detail. Second, the static analysis and modal analysis on the integrity of two kinds of structure are carried out by finite element analysis software ANSYS workbench, and the deflection of the two structures due to their own weight is obtained in the static state, and the first six order natural frequencies of the two structures are obtained. And then, through the comparison of simulation results, the structure of screw and spline shaft produces less deflection than the structure of telescopic rod, moreover, the natural frequency of the structure of screw and spline shaft is significantly higher than the structure of telescopic rod. The structure of spline shaft and screw has good feasibility and stability.This equipment can be well applied to the Analysis and Transfer System of Seafloor Natural Gas Hydrate Pressure Core to complete testing and cutting action. Last but not least, in order to verify the operability and stability of the structure of screw and spline shaft, a preliminary experimental model has been produced. Through a series of experiments, it can be analyzed that the structure of spline shaft and screw has good feasibility and stability.