低渗透气藏直井压裂产能评价公式

Deliverability evaluation formula of vertical well fracturing in low permeability gas reservoirs

在拟径向流阶段,有效井筒半径是无因次裂缝导流能力的一个函数。在此基础之上,提出了新的简单实用压后气井产能评价公式。通过文献中两个实例的计算对比验证了该公式的可靠性。分析了多种因素对气井产能影响的强弱程度,结果表明由强到弱的因素依次为地层压力、地层温度、有效厚度、渗透率、裂缝半长、表皮系数、裂缝导流能力。要提高气井产能,行之有效的手段是通过酸化压裂等增产措施来解除近井地带表皮污染和建立高导流能力的渗流通道。

In the pseudoradial flow period, an effective wellbore radius is like a function for dimensionless fracture diverting capaci ty （FCD）. On this basis, a new simple and practical deliverability evaluation formula of fractured gas well is proposed. The reliabili ty of the formula was proved by comparing two examples calculation in literatures, thereby analyzing the degree of various factors in fluencing gas well deliverability. The results show that the order of factors from strong to weak is formation pressure, formation tem perature, effective thickness, permeability, fracture half-length, skin factor, fracture conductivity. In order to improve gas well pro ductivity, the effective means are using stimulation treatment of fracturing and acidizing, which can resolve near-well formation damage and establish flow channel with high flow conductivity.