利用地下油气渗流理论研究了垂直裂缝气井中气体的流动过程和渗流方程,并对各个流动过程建立了相应的数学计算模型,在此基础上,推导出了垂直裂缝井的不稳定渗流产能预测公式。应用该公式对吉林油田某垂直裂缝气井进行了例证分析,得出的计算值和实际值的误差为3.4%,并且通过预测公式分析了地层渗透率、地层压力、气藏厚度、裂缝长度、裂缝导流能力等参数对垂直裂缝气井产能的影响情况。该不稳定渗流产能预测公式的提出解决了常规汇源函数计算过程复杂和计算速度慢的问题,实现了垂直裂缝气井渗流方程的快速求解。
The flow process and filtration equations of gas in vertically fractured well was researched using the seepage theory of underground oil and gas, and then the corresponding mathematical model of each flow process was established. And then the transient productivity prediction formula of vertically fractured well was deduced based on this. The application of this production forecasting formula obtains that the error is 3.4% between the calculated value and the actual value in Jilin oilfield. The effect of formation pa- rameters and fracture 13arameters, including formation permeability, formation pressure, gas reservoir thickness, crack length, fracture diverting capacity, on productivity of vertically fractured well were analyzed through the forecasting formula. The proposed of transient flow productivity prediction formula solves the problem of complicated calculation process and slow computation speed of conventional catchment source function, and realizes fast solution to seepage equation of vertically fractured well.