影响鄂尔多斯盆地致密砂岩储层水力压裂效果关键因素分析

Analysis of key factors affecting fracturing effectin tight sandstone reservoir

为了明确影响鄂尔多斯盆地致密砂岩储层水力压裂效果关键因素,针对水力压裂过程中影响压裂效果的隔储层应力差、隔储层杨氏模量差和储层渗透率等关键因素,利用FracPro2019压裂模拟软件进行数值模拟分析。模拟研究结果表明:1)当隔储层应力差小于5.86 MPa时,裂缝高度很容易突破储层进入隔层,而当压力差大于5.86 MPa时,裂缝高度将很容易控制在储层之内;2)当隔层杨氏模量低于中间储层时,储层压裂裂缝宽度大,压裂液流动阻力小,流压较低,净压力也小,产生的裂缝高度就低;3)随着渗透率降低,压裂液滤失减少,压裂效率增加,当渗透率低于0.1 mD时,压裂液滤失减少幅度减小。该研究成果认识,对指导鄂尔多斯盆地致密砂岩储层水力压裂设计具有指导意义。

In order to clarify the key factors that affect the fracturing effect of tight sandstone reservoirs in Ordos Basin,the FracPro2019 fracturing simulation software was used to conduct numerical simulation analysis on the key factors that affect the fracturing effect during the fracturing,such as the reservoir permeability,the stress difference and the Young’s modulus difference between the interlayer and reservoir.The simulation research results indicate that:1)The fracture is easy to break through the reservoir and enter the reservoir when the stress difference between the interlayer and reservoir is less than 5.86 MPa,and the fracture height would be easily controlled within the reservoir when the pressure difference is more than 5.86 MPa;2)The fracturing fracture width could become low and its height become large due to the small flow resistance,the flow pressure,and the net pressure of the fracturing fluid when the Young’s modulus of the interlayer is lower than that of the middle reservoir;3)The filtration rate of the fracturing fluid decreases,and the fracturing efficiency increases as the permeability decreases.However,the reduction in filtration rate of the fracturing fluid decreases when the permeability is below 0.1 mD.The above achievements are of guiding significance for the fracturing design of tight sandstone reservoirs in Ordos Basin.