Failure Analysis And Improvement Of New Bridge Type Eccentric Spout Concentric Water Distributor

Water injection is the main extraction method to replenish formation energy,achieve stable production and increase recovery rate of oilfield.Existing stratified injection bridge type eccentric spout concentric water distributor often fails to achieve normal water injection,for this reason,this thesis conducts stress strength study and failure analysis on this type of water distributor,and improves the failure structure.The article carried out a three-dimensional reconstruction of the original bridge-type eccentric spout concentric water distributor which could not achieve the normal water injection function.Through on-site photos,it was found that the keyway on the central core rod was plastically deformed and thick oil and impurities were attached to the spiral drive structure;Further analysis concluded that,in addition to the plastic deformation of the failed structure,another cause of the inability to fill the water distributor was that the seal on the mid-core rod moved up and down with the mid-core rod,resulting in gap galling,causing the seal to fail and ultimately causing the water distributor to fail to fill;This paper verifies the causes of failure through internal force analysis,mechanical and theoretical analysis and simulation analysis of the existing concentric water distributor with bridge type eccentric spout,and improves the failed structure under the condition of ensuring the fine water injection of the distributor.By analyzing the internal forces of the water distributor and applying the knowledge of material mechanics to the mechanical analysis of the failed structure,the root cause of the plastic deformation of the keyway was found to be the excessive contact stress at the failure site.On the basis of not affecting the function of the water distributor,a new antiself-rotation structure is designed for the improvement of the failed structure to avoid problems such as excessive contact pressure,solving the problem of plastic deformation of the components,selecting new seals and replacing the material so that the seal failure caused by gap galling will not occur under the same working medium pressure,and carrying out force analysis on the optimized structure to ensure that plastic deformation will not occur under high torque;After determining its specific structure,ANSYS software was used to strength check the new structure and the main components of the water distributor.By using kinematic principles and ADAMS simulation software,a detailed motion analysis of the threaded drive structure was carried out to gain an in-depth understanding of its characteristics and performance and to verify the realizability of the new structure’s function of adjusting the spout opening.This paper verifies the causes of failure through internal force analysis,mechanical and theoretical analysis and simulation analysis of the existing concentric water distributor with bridge type eccentric spout,and improves the failed structure under the condition of ensuring that the water distributor is filled with water.