页岩气井产能评价方法研究

Productivity evaluation method of shale gas well

页岩气开发主要依靠水平井分段水力压裂技术获取产量,页岩气井产能与地质因素和工程质量有紧密关系。总结了常规气藏中应用较为广泛的气井产能特征分析方法,探讨了这些方法对于页岩气井的适用性,指出页岩气井投产初期产能递减迅速,常规的产能评价方法主要用于评价气井的瞬时产能,不完全适用于页岩气井。在此基础上提出了一种新的便于比较页岩气井产能特征的分析方法,综合评价页岩气井投产一段时间内的产能,根据新方法的计算结果分析了页岩气井的产能影响因素,并将该方法成功用于分析国内某页岩气区块的14口试采井,应用效果较好。

Horizontal wells with multi-stage hydraulic fracturing are now the primary methods to achieve economic production rates in shale gas plays.The productivity of horizontal wells is closely related to geological factors and engineering qualities.Commonly used analysis methods of productivity characteristics for gas wells in conventional reservoirs were summarized and their adaptabilities to shale gas wells were discussed.The conventional methods could evaluate instantaneous productivity of a gas well but are not fully suitable for shale gas wells of which the productivity declines quickly in early days of production.Upon this fact,we proposed a novel analysis methodology for shale gas wells based on which the productivity during some time could be comprehensively evaluated.With the results of the new method,influencing factors of productivity were analyzed and the new methodology was applied to 14 production test wells in a domestic shale gas block to validate its practicability.