Pressure Transfer Law Study Of Progressive Cavity Pump Lifting Technology

The progressive cavity pump(PCP) oil extraction system is an infant artificial lift method, which would have the particular merits and be of great importance by foreign oil field. But the faultiness study of PCP and corresponded oil extraction technics limited the predominance of PCP oil extraction. Therefore, the purpose of this paper is to improve the work characteristics and strengthen the adaptability of PCP, and realize the lifting efficiency of PCP oil extraction well, reduce the oil extraction cost and improve the oil extraction benefits. The produce of PCP lifting pressure and pressure transfer law were described firstly. The results of this study demonstrated that the cause of PCP pressure produce is the oil fluid increases of PCP vent unceasingly, the liquid column elevation and heightened the vent pressure. The pressure transfer process is as the result of pressure difference increases between the neighborhood cavity with the help of the pressure increases. When the pressure difference exceeded the contact pressure, the sealing invalided and the flee stream of oil fluid resulted in the pressure transfer to the imbibe orifice.The two direction finite element model was carried out by using nonlinearity analysis software ANSYS, which based on two direction entity cell and contact cell. The simulation and calculation of contact pressure of stator and rotor at different pressure and pressure difference of PCP cavity were performed by means of two direction finite element model. The conception of critical contact pressure and maximum seal pressure difference were defined. Besides, based on the critical contact pressure curve, the pressure field distributing of PCP lifting pressure which passed behind were simulated and optimized .By use of this method, the influence of latex materials hardness, Poisson's ratio and amount of interference to critical contact pressure curve were analyzed, and reflect the affects of these parameters to PCP lifting pressure. The results showed that the lifting pressure increases with the latex materials hardness, Poisson's ratio and amount of interference, and this conclusion provides study field for further research of efficiency lifting pressure PCP.Finally, the pressure-transfer law study of iso-wall thickness PCP lifting technology. The results verified that the lifting pressure of iso-wall thickness PCP was higher than general PCP in the same condition, which have an advantages in increases of PCP lifting pressure.