The invention discloses a
coiled tubing tubular column device and a brine discharging and capacity expanding method thereof for a salt cavern
underground gas storage reservoir. The
coiled tubing tubular column device comprises a
coiled tubing, a tubing outside connector,
a weighting pipe, a hydraulic safety joint and a rotary washing tool. The brine discharging and capacity expanding method comprises the following steps: firstly, screening a gas storage reservoir waiting for capacity expansion, and determining brine discharging capacity; secondly, installing a coiled tubing operation
machine, ground corollary equipment and pipelines; thirdly, installing a well mouth
well control device and the coiled tubing tubular column device, and testing sealing performance; fourthly, unloading the coiled tubing tubular column device, and injecting gas for brine
discharge; fifthly, washing blocked dregs and discharging brine; and sixthly, taking out the coiled tubing tubular column device and a brine discharging tool. Brine
discharge and capacity expansion are carried out by adopting the coiled tubing tubular column device, the coiled tubing can be arranged into a cavity bottom or the dregs, the blocked dregs can be effectively washed by using the rotary washing tool, a brine discharging passage can be formed again, and smaller than 20% of residual brine remaining at the bottom of the cavity incapable of being discharged in a traditional brine
discharge pipe can be effectively discharged.