Ali Zareiforoush - No. ۱, Mehran Alley, North Sheikh-Bahaie St., Molla-Sadra Ave.,Tehran, IRAN.
Alireza Hosseinbagheri - No. ۱, Mehran Alley, North Sheikh-Bahaie St., Molla-Sadra Ave.,Tehran, IRAN.
Hassan Mehrabi - No. ۱, Mehran Alley, North Sheikh-Bahaie St., Molla-Sadra Ave.,Tehran, IRAN.

Multiphase flow occurs in almost all producing oil and gas/condensate wells. Wellhead chokes are special equipment that widely used in the petroleum industry to (1) control flow rate, to (2) maintain well allowable, to (3) protect surface equipment, to (4) prevent water and gas coning and to (5) avoid formation damage from excessive drawdown. Gas flow velocity and rate especially through chokes had been studied by numerous investigators, different choke flow models are available from the literature, and they have to be chosen based on the flow regimes, that is, subsonic or sonic flow. Also when the fluid velocity is high, erosion damage occurs and subsequently results in critical flowing condition.A comprehensive review of these correlations indicated that they are not theoretically rigorous and give inaccurate flow rate for the real conditions. Thus these correlations need to be modified. Al-Attar plotting method also used by seperator test data set to predict flow rate and the method accuracy was discussed. The results of this work are very important in the design and implementation of deliverability tests, pressure transient tests, well control, and long-term well production. These results should encourage the production engineer which works at such condition to utilize the optimum correlations for future practical answers when a lack of available information, time, and calculation capabilities arises

Choke Flow Model, Correlation, Flow Velocity, Critical Condition, Gas Flow Rate