A scientific and well-established approach to evaluation and classification of gas wells plays an important role in management of low-permeability gas reservoirs. In this paper, we present a new classification system for horizontal wells, based on dynamic data from 40 wells in the Su-14 block of the Sulige field. We also introduce such evaluation parameters as the drop in well production with a decrease in casing pressure, the casing pressure drop rate, and absolute open flow. We propose using cluster analysis for evaluating the performance of Su-14 wells and for classification of the wells. Analysis of three wells has confirmed that the proposed method is reliable and accurate. This classification method is of considerable theoretical and practical value, and can be used for other similar gas fields.