Productivity of a number of gas wells is decreasing as a result of water accumulation at the bottomhole leading to slowing-down the gas flow inside the well. This is extremely urgent for mature oil fields. If the liquid level in well is not attenuated, liquid is accumulated and aggravates the conditions of gas production, upon that well productivity could be significantly reduced up to complete output stop and well killing. It happens because of gas undercapacity to transport liquid accumulated inside the wellbore. Liquid accumulation leads to backpressure which precludes influx from the pay zone. In order to avoid liquid accumulation at the bottomhole water and condensate must be lifted to surface together with the gas. The most efficient method for well recovery is installing smaller-diameter tubes in production string. Reducing the flow area of a gas well increases gas capacity to transport liquid up to wellhole. Liquid does not accumulate at the bottomhole and productivity restores. Upon that gas velocity should not exceed critical velocity needed for prevention of liquid accumulation at the bottomhole. Installing smaller-diameter strings can be done without killing a well. Used for this purpose string of smaller-diameter tubes are referred to as velocity string.