The Research And Design Of The Spin Water Jet Blockage Removal Tool

In the process of oil well exploitation,due to the near-wellbore stratum blockage and casing perforation holes blockage,the water injection pressure will increase and the permeability will decrease,which can influence the yield.Blockage removal technology is an important method to solve well blockage.Acidizing and blockage removal agents are the main methods for the well blockage.The blockage removal technology includes the physical method and chemical method.In order to solve the problem of casing blockage,a spin blockage removal tool based on water jet technology was designed.The mechanism of water jet erosion process of blockage is discussed.Firstly,the classification of the blockage are introduced.The scaling sample of a water-injection well from Shengli Oilfield is test by XRD.The result showed the sample of blockage is Fe CO₃,which coincided with the research,which indicated that the blockage of water injection well is mainly inorganic salt.The tool used the nozzle jet to drive the spray-head to rotate,which can rotate and jet meanwhile.To decrease the revolving speed,the centrifugal damping is set.Secondly,the parameters of the blockage removal tool are analyzed by using the theoretical calculation and numerical simulation.The parameters includes the performance parameters,pressure and structural parameters.The theoretical formula of revolving speed is derived.The relationship between the pressure and the speed is analyzed.The relationship between pressure and water jet velocity is analyzed by CFD method.The nozzle shape,nozzle structure parameters and nozzle shrinking angle are analyzed.The water jet erosion process is simulated by ALE method.The erosion model was established by ANSYS.A type of gypsum was regarded as the erosion material.The pressure distribution of the submerged water jet in the process of scale erosion is analyzed by comparing with the non-submerged jet.The volume change of gypsum in erosion process is discussed.And the relationship of the water jet velocity,revolving speed and erosion volume are discussed.Finally,according to the design plan,the assembly drawing was made.The prototype was manufactured and experimented.Through the experiment,the design of the blockage removal tool is test.Combined with the experiment and numerical simulation,the water jet range and impact force are discussed.In conclusion,the rate of flow is the important factor of the effect of the tool.With the rate of flow increasing,the range of water jet and impact force are increased.