Application Study on Typical Production Decline Curves of Shale Gas Wells in the Fuling Jiaoshiba Block

To reveal the production decline pattern and the influencing factors of shale gas wells in Fuling Jiaoshiba Block, a typical decline curve of normalized quasi-production and material balance time by means of fitting method was developed on the basis of typical shale gas production data. At the same time, the impact of initial production capacity, production history, production allocation, water production, formation pressure and bottom hole flow pressure value accuracy on the typical production decline curve and recoverable reserve evaluation were also studied. In addition, applications of the typical production decline curve in recoverable reserve evaluation, reasonable production allocation and flow stage division were also analyzed. The results showed that the typical production decline curve used in recoverable reserve evaluation can take account of current production characteristics and production changes of the well, it demonstrates that this method is more reliable than the conventional material balance method, the elastic 2-phase method and empirical analogy method. Productivities and production patterns of shale gas wells change dynamically, so production is allocated in a rational manner. In addition, great attention should be paid to the difference among blocks, wells and production stages. By using the double logarithmic curve of normalized quasi-production and material balance time, the flow stage of shale gas wells can be determined based on the slopes in a complete production cycle. The results can provide references and guidance for evaluation of recoverable reserve, the rational production allocation and block development plan design of shale gas wells in the Fuling Jiaoshiba Block.