American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. This paper was prepared for the 49th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Houston, Texas, Oct. 6–9, 1974. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. Abstract A system is described for detecting and diagnosing problem gas lift wells based on well test data. Wells are screened so that only those with abnormal producing conditions are identified for further analysis. The analysis utilizes well tests and installation specifications to define troubles and predict efficient gas injection rates. This method circumvents the need for numerous flowing pressure and temperature traverses in pressure and temperature traverses in continuous flow gas lift facilities. Introduction Gas lift wells are subject to the following kinds of design and operating problems: Surface Excessive flowline restriction Tubing or casing choke plugging Undersized flowlines High separator pressure Undersized gas distribution systems Wet gas Subsurface Leaks in the flow string Improper flow valve operation Improper design of string Changing well conditions Excessive aeration Excessive slippage of fluid or fallback Foam conditions Low fluid heads or submergence heading or surging conditions Conventional methods to detect and diagnose inefficient gas lift wells can require many of the following: Well tests Casing-tubing pressure recordings Surface temperature recordings Pressure traverse surveys Temperature surveys Fluid levels determined by acoustic methods But in a large scale gas lift field, it is expensive and time consuming to get the necessary down-hole data.