Horizontal well dynamic evaluation method in shale gas reservoirs

Shale gas reservoirs are different from conventional gas reservoirs in reservoir characteristics, percolation mechanism, completion technique, and dynamic performance. Since the development of shale gas in China is still at the stage of exploration, dynamic regulation and evaluation method of overseas shale gas well were summarized to provide some models and the reference for establishing domestic shale gas well dynamic evaluation and process measures. Based on the field case study and literature review on overseas’ shale gas wells, the flowing mechanics and production performance of horizontal wells were summarized. The current dynamic performance evaluation methods for shale gas horizontal wells were described in detail, which includes flow region identification, effective fracture parameters calculation and gas reserves determination in SRV. From the point view of gas well flow characteristics, unstable linear flow is the mainly flow characteristics for horizontal wells in shale gas, and the effective fracture parameters formed after horizontal well fracturing can be evaluated according to the dynamic data in this stage. On the other hand, some wells appear boundary flow after linear flow, which means the whole stimulation range generally in a state of exhaustion, and the dynamic reserves within the stimulation region can be evaluated using this feature.