水平井产能计算新方法

研究表明,低渗透油藏中存在启动压力梯度及应力敏感效应,且在钻完井及试油过程中,由于钻井液滤失,易导致储层污染。推导了同时考虑启动压力梯度,应力敏感效应及表皮因子的低渗透油藏水平井压力分布及产能公式,运用质量守恒原理及二分迭代法得到水平井产量精确解。并以某油田为例,进一步分析了启动压力梯度,应力敏感效应,表皮因子等因素对水平井产能的影响。最后,对比了几种经典水平井产能计算方法,结果表明运用本文公式计算水平井产量是合理可靠的。

A NEW PRODUCTIVITY FORMULA FOR HORIZONTAL WELL

Studies have shown that threshold pressure gradient and stress sensitivity exist in low permeability reservoirs. In the process of drilling and well completion and oil testing, formation will be damaged .In this paper, pressure distribution and production formula of low permeability reservoir are derived by taking account of threshold pressure gradient, stress sensitivity,skin factor and the accurate solution of productivity is obtained using the principle of conservation of mass and bisection iteration. On this basis, threshold pressure gradient, stress sensitivity and skin factor are analyzed which influenced on the horizontal well productivity. Finally,several typical horizontal well production calculation methods are compared.The result shows that the formula in this paper is reliable and reasonable and the application of this new method has certain guiding significance in horizontal well of low permeability reservoir development.