涪陵焦石坝区块页岩气井动态合理配产技术

The Technique of Rational and Dynamic Production Allocation of Shale Gas Wells in Jiaoshiba Block,Fuling Area

涪陵页岩气田焦石坝区块页岩气井的渗流特征、产量递减特征和生产特征呈现分阶段变化和分区差异性,目前没有适用该类页岩气井的配产方法。借鉴国外页岩气生产经验,根据页岩储层应力敏感试验结果和实际生产情况,确定采用定产控压的生产方式。在此基础上,借鉴常规气藏配产方法,根据该区块页岩气井实际生产特征,选用采气指示曲线法和不稳定产量分析法确定不同产能页岩气井的合理配产系数。引进页岩气井分区、分阶段动态合理配产的理念,结合分区不同产能区间页岩气井产能的递减规律,按照页岩气井当前累计产气量对应产能的合理配产系数调整配产。按照此方法对涪陵焦石坝区块页岩气井的配产进行了调整,调整后既满足了该区块页岩气井稳产3年左右的需要,又使页岩气藏获得了较高的采收率和较好的经济效益。

The characteristics of flow,productivity reduction and production of shale gas wells in the Jiaoshiba Block of Fuling Gas Field can be summarized as variations in different production stages and different regions.At present,a production allocation technique is not available for such shale gas wells.Under such circumstances,studies have been conducted for rational and dynamic production allocation of shale gas wells in Jiaoshiba Block,Fuling Area.With consideration to field practices of shale gas production around the world,stress sensitivity testing results of shale core and actual production of shale reservoirs in the block,the production mode with constant productivity under properly controlled pressures was developed.In addition,taking into consideration production allocation techniques for conventional gas reservoirs and field production features of shale gas wells in the Block,rational production allocation parameters for shale gas wells with various productivities were identified through application of production allocation method of gas production indication curve and the unsteady productivity analysis techniques.With the introduction of concepts related to rational and dynamic production allocation of shale gas wells in different zones and stages as well as patterns of gas well productivities in different zones,production allocation can be achieved by adjusting proper production allocation parameters in accordance with present cumulative productivity of the wells.The newly-developed technique has been applied in production allocation in the Jiaoshiba Block of the Fuling Gas Field.In addition to satisfying the three-year steady productivity requirements for shale gas wells in the Block by using production allocation,the technique can effectively enhance recovery rates and economic performances of shale gas reservoirs.