Study on the Performance of Combination Seals Under Stress Relaxation
Combination with the high-temperature and high-pressure conditions in the drilling process and Stress relaxation(SR)characteristics of rubber,the rotatory combination seal was subjected to bilateral pressure by the loading method of pressure penetration in the finite element analysis,and the influence of drilling fluid pressure,downhole temperature on the main sealing surface of the combination seal was analyzed.Combination with the finite element analysis results,the deformation matrix was extracted,and a numerical analysis model of rotary combined seal based on thermoelastohydrodynamic lubrication(TEHL)theory was established.The oil film thickness and oil film pressure distributions under different downhole temperature,spindle speed when SR was taken into consideration were obtained by numerical method.The results show that after considering stress relaxation,the higher the medium pressure is,the greater the contact pressure will be,hence the tightness is good and it is not easy to leak,and the friction force will increase.As the temperature rises,the contact stress is almost equal to the medium pressure,when the leakage will increase,and the temperature rise will also cause a decrease in viscosity,making the viscous friction decrease.The increase of roughness causes the increase of oil film thickness and the decrease of oil film pressure,leading to the rapid increase of leakage and the slight decrease of friction.Leakage rate and friction force increase with spindle speed.
high temperature and high pressurestress relaxationrotary combination sealfrictionTEHL
万方数据
维普
