Research of sand occurrence in directional gas-lift wells
The article considers problems relating to studying of sand occurrence in directional gas-lift wells. Study of tubing curvature effect on sand plug fluidization is experimentally carried out. It is proved that the maximum height of the sand particles in suspension state and the corresponding maximum flow rate are observed at an inclination angle of 30°. The effectiveness of periodic injection of a working agent while applying gas-lift method of directional wells operation with a high content of mechanical impurities in the product is set up and the possibility of regulating their operational modes is shown. It is revealed that periodic flow of working agent is more effective when operating directional gas-lift wells, however, with angle increase of more than 30º the effect decreases. The maximum effect in this case, regardless of the wellbore curvature degree, is marked at one and the same rate of working agent injection. Besides, periodic gas supply when operating wells with sand occurrence not only improves the structure of the pseudo-fluidized layer, but also improves the lift performance. Almost all cases witness some decrease of working agent consumption.