低渗透气藏垂直裂缝井产能计算

Deliverability Calculation for Gas Wells with Vertical Fracture in Low Permeability Reservoir

低渗透气藏储层往往存在着渗透率应力敏感性,且地层中气体流动时具有启动压力梯度。考虑以上因素对气井产能的影响,根据扰动椭圆的概念和等价的发展矩形的思想,推导出适合低渗透气藏的气井压裂后产能预测公式,绘制并分析了产能理论曲线。研究表明,渗透率模数、拟启动压力梯度以及裂缝的长度均对气井产能有较大影响。该研究结果对低渗气藏垂直裂缝井合理产能的求取具有较好的指导意义。

Permeability-stress sensibility exists usually in low permeability reservoir,and so does a start-up pressure gradient for gas flow.Considering influence of above factors to the deliverability of gas well,and based on the concept of disturbance ellipse and the idea of equivalent development rectangular,deliverability formula of gas wells with fracture in low permeability reservoir is derived and theoretical deliverability curve of these wells is plotted and analyzed.The study shows that the deliverability of gas well is seriously effected by permeability modulus,pseudo-start-up pressure gradient and fracture length.The result is a guidance to reasonable deliverability calculation of gas wells with vertical fracture in low permeability reservoir.