低渗油藏压裂水平井生产动态物理模拟

针对长庆油田某区块采用的纺锤形和哑铃形2种裂缝分布形式的压裂水平井，制作三维比例物理模型，进行了压裂水平井弹性开采及水驱物理模拟研究。结果表明，2种模型在弹性开采条件下，产油量与时间呈指数函数关系变化，哑铃形压裂水平井的产量较高，产量递减速度较快；利用压裂水平井产能公式和封闭油藏弹性驱动物质平衡方程，推导出产量的指数表达形式，分析了弹性开采条件下产量及其递减速度的影响因素。在水驱条件下，纺锤形压裂水平井见水时间较晚，含水率上升速度较慢。在水驱实验初期，弹性驱动占据主导地位，哑铃形压裂水平井的产量较高，当累积注水量大于0.2 PV后，纺锤形裂缝分布模型的采出程度开始逐渐大于哑铃形裂缝分布模型。当含水率达到98%时, 纺锤形和哑铃形裂缝分布模型的采出程度分别为33.67%和27.48%。

Physical simulation of production performance of fractured horizontal wells in low permeability reservoir

For the fractured horizontal wells with spindle and dumbbell-shaped distribution of fracture in the Changqing oil-field, 3-D scaled physical models are utilized to simulate their production performance in elastic drive and waterflooding. The experimental results indicate that the oil production and the experimental time of two models are closely exponential function. The oil production of the horizontal well with dumbbell-shaped fracture is higher, but its decline rate is faster. The productivity formula and material balance equation of closed reservoir with elastic drive are utilized to derive the exponential form of oil production. Influence factors of oil production and its decline rate are analyzed in elastic drive. In waterflooding, the water breakthrough time of the horizontal well with spindle fracture is later than the one with dumbbell-shaped fracture. And the rate of water cut increasing of the model with spindle fracture is slower. In the initial stage of waterflooding experiment, elastic drive is still the leading position, so the oil production of the model with dumbbell-shaped fracture is higher. When the cumulative water injected exceeds 0.2 PV, the recovery percent of the model with spindle fracture is higher than the one of the model with dumbbell-shaped fracture. When the percent water cut reaches 98%, the recovery percent of the model with spindle fracture is 33.67%, while the one of the model with dumbbell-shaped fracture is 27.48%.