Exploration and Development Ｒesearch Institute，Northeast Oil ＆ Gas Branch of SINOPEC，Changchun 130062，China

 As volcanic reservoirs have strong heterogeneity and poor seepage stability compared to conventional sandstone reservoirs，it is difficult to accurately evaluate the productivity of volcanic gas wells． To solve this problem，based on the productivity test on eight volcanic gas wells in the Songnan gas field of the Changling fault depression in the southern part of the Songliao Basin，the authors constructed the binomial capacity equation by using the“back pressure test”，and by using the “one-point test”to generalize the empirical equation of productivity． Then two kinds of productivity test methods of volcanic gas reservoirs were established． In the early stage of volcanic gas reservoir exploration when there are fewer wells，it is more suitable to use the“back pressure test”to improve the accuracy of productivity test． While in the middle and late stage of volcanic gas reservoir development，the “one-point test”can effectively improve the efficiency of productivity test and save costs when more test data are available． By combining the two methods，the productivity of volcanic gas wells can be evaluated more accurately and efficiently．