低渗透油藏长缝压裂直井稳态产能预测模型

低渗透油藏长缝压裂直井已在现场获得广泛应用,但目前仍缺乏适用于其工程应用的快速、准确的产能预测模型。为此,根据低渗透油藏长缝压裂直井周围地层渗流情况,运用保角变换原理与双线性渗流理论,建立了低渗透油藏压裂裂缝无限与有限2种导流能力下、考虑启动压力梯度长缝压裂直井稳态产能预测模型,通过与现场实例对比验证了模型的准确性,并利用该产能预测模型计算绘制了油井IPR曲线,分析了裂缝参数对长缝压裂油井产能的影响。结果表明:新建产能预测模型与现场实例基本相符,误差均小于9%,说明模型的准确性较高;长缝压裂直井压裂缝长对产能的影响程度大于裂缝导流能力对产能的影响;当压裂缝长一定时,长缝压裂直井裂缝存在最佳导流能力。

Steady- state productivity prediction model for long- length fractured vertical well in low permeability oil reservoirs

Long-length fractured vertical well has been applied widely, but there is still not productivity prediction model for longlength fractured vertical well in the low permeability oil reservoirs. In view of the fluid flow mechanism around the vertically fractured well, the productivity prediction model of long-length fractured vertical well with infinite conductivity and finite conductivity is derived by using conformal transformation and bilinear flow theory in consideration of starting pressure gradient. The IPR curve is draw to analyze the influences of hydraulic fractured parameters on long-length fractured vertical well productivity. Combined with the actual example, the accuracy of this prediction model is verified. The well productivity is influenced by the fracture length more deeply than the fracture conductivity, and there is an optimal fracture conductivity for long-length fractured vertical well under certain fracture length.