The kinetic characteristic and opening condition of fixed valve for sucker rod pump in CBM wells
Abstract：The mathematic models of kinematic law and opening condition were developed based on the opening pressure drop of fixed valve.The kinematic relation,hydraulic loss and critical submergence depth of fixed valve under different working condition were obtained with the realistic model.The results show that the critical submergence depth in the wellbore can reveal the phenomenon of the valve shutting down and intermittent water flow at the wellhead.An increased stroke and pumping speed results to an increased displacement of the valve ball and variation of initial velocity.And it is beneficial for the well liquid to go into the valve,enhances the ability to carrying coal dust,and makes the valve tremble and decline the pump efficiency.The instantaneous acceleration and hydraulic loss of the fixed valve are large,the frequencies of oscillation are high,and become low during the stroke.The critical submergence depth and hydraulic loss increase due to the size of pump and pumping speed.And based on the maximum hydraulic loss,the critical submergence depth can be obtained within 3～5 m for the pump of 38 mm and 44 mm.
Keywords：CBM wellsucker rod pumpfixed valvelow submergence depthopening condition
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 810-814 )