复杂渗流条件下致密气藏压裂气井分区产能计算方法

Zoning Productivity Calculation Method of Fractured Gas Wells in Tight Gas Reservoirs under Complex Seepage Conditions

致密气藏压裂气井渗流机理复杂,压裂改造区内外渗流机理和影响因素也截然不同,常规的产能计算模型不能准确描述这种存在区域差异的渗流特征,造成最终产能计算误差较大。以气体渗流理论为基础,分析了在致密气藏压裂气井分区域渗流机理,明确了压裂气井不同区域的渗流特征及影响因素。在此基础上建立了复杂渗流条件下的致密气藏压裂气井分区产能计算方法并开展了实例验证。计算结果表明,分区产能计算模型计算产能更加接近气井实际,较现有模型更加准确可靠。

Fracturing gas wells in tight gas reservoirs show complicated seepage mechanisms,and the seepage mechanisms and influencing factors differ greatly in and outside the fracturing zone.Conventional productivity calculation models cannot accurately describe such seepage characteristics with regional differences,resulting in large errors in final production prediction.Based on the gas percolation theory,the seepage mechanisms of fractured gas wells in tight gas reservoirs were analyzed in subregions,and the seepage characteristics and influencing factors in different regions of the fractured gas wells were determined.On this basis,a numerical model for calculating the production capacity of fractured gas wells in tight gas reservoirs under complex seepage conditions was established and verified by examples.Results show that the gas well productivity calculated by the newly designed zoning productivity calculation model is closer to the actual gas well.The new model is more accurate and reliable than the existing ones.