Tubing collar inserts for producing gas wells below the critical velocity

Liquid production can be a problem in gas wells if the liquid cannot be lifted from the wellbore and accumulates in the production string. Liquid accumulation can cause a gas well to die. Tubing collar inserts can keep gas wells unloaded by droplet transport and by prevention of downward liquid flow. Criteria for insert application calls for a churn flow regime, gas superficial velocity less than critical velocity, and no excessive pressure drop caused by flow through the inserts.