Method study on anomalous pressure gas wellhead choke valve turndown ratio control

In view of application of wellhead throttle unit in Dina2 gas field,for the purpose of accurately controlling gas produc-tion rate,regulation method for two-stage choke valve turndown ratio is studied and developed in this paper.Based on the relationship between oil pressure and production rate,this method is used to firstly control wellhead pressure and all-levels pressure after throttle to approximately control the production rate.And then,control valve Cv value is computed in accordance with relevant pressure and production rate.According to Cv value,two-stage choke valve turndown ratio is computed for accurate gas production regulation.Field application demonstrates that this method is one feasible means for efficient production regulation and wellhead parameter adjustment in anomalous pressure gas well.