Design And Study On Down-hole Helico-Axial Multiphase Pump

Down-hole helico-axial multiphase pump is a new technology for pumping underground oil and gas mixture. In order to meet the needs of the high gas wells, offshore marginal oil wells and coalbed methane wells development, our laboratory designed the down-hole helico-axial multiphase pump, and studied the existing problems of the pump.Axial force is an inevitable problem to the helico-axial multiphase pump. in order to predict the helico-axial pump axial force and get the calculation method accurately, especially get the calculation method to the gas-liquid mixture during pumping axial force, this paper analysis the mechanism of the axial force of the helico-axial multiphase pump, studies the distribution of the fluid by using the basic principles of fluid mechanics. The calculation methods and formulas to the helico-axial multiphase pump axial force is put forward by researching the three contribute axial force, this method not only applies to single-phase working medium, but also applies to on the gas-liquid mixture working medium.In order to solve the problem of the axial force balance of the down-hole helico-axial multiphase pump that is difficult to settle, this article found that the traditional axial force balance is very difficult to apply to down-hole helico-axial multiphase pump because it works inefficient by summarising an compare the traditional axial force balance method. This paper designed two new axial force balance devices - the "double-shell balancing pipe & balancing disc" axial force balance device and the "double-shell balancing pipe & balancing drum" axial force balance device, and its structure characteristics and working principle is analyzed. By commparing several common axial force balance device, two new axial force balance devices has obvious advantages in terms of balance, or in ways to improve pump efficiency. the balance device provide a new way to balance the axial force of the down-hole helico-axial multiphase pump. To determine the radial clearance between the blade wheel and guide wheel - blade tip clearance, the tip clearance leakage flow field is studied. this paper established the blade wheel and guide wheel model by using a three-dimensional modeling software SolidWorks, analysed the model by using theusing numerical simulation software FLUENT. By analyzing the distribution of blade center axial velocity vectors obtained the relationship between the size of the tip clearance, transport medium gas flow rate, pump flow and the inside flow field;by studying the distribution of the axial impeller outlet velocity, obtained the relationship between the tip clearance and the axial velocity; by studying distribution of the impeller exit radial velocity, obtained the relationship between the tip clearance and the radial velocity.This paper designed the key components of the down-hole helico-axial multiphase pump and assemble the entire pump by using the parts that have been made two-dimensional drawings and three-dimensional map, introduced the work process and installation procedures of the down-hole helico-axial multiphase pump. The key parts of them had strength calculation, the calculation shows that the balancing disc of mixed plates, keys, pump housing and other structures of the helico-axial multiphase pump meet the work requirements.