页岩储层SRV影响因素分析

Analysis of the factors of influencing stimulated volume of shale reservoir volume fracturing

为了计算页岩储层压裂改造体积,建立了与施工参数相关联的储层改造体积SRV(Stimulated Reservoir Volume)计算模型。应用该模型研究了弹性模量、泊松比、地应力差、储层厚度等因素对储层改造体积的影响,分析得知泊松比和水平主应力差存在临界值,分别为0.36 MPa和6 MPa,超过临界值后难于形成缝网。通过页岩储层实例分析得出储层改造体积随着压裂排量的增加而增大,施工排量存在一个最佳值10 m3/min;储层改造体积随着液量的增加而增大,增幅先增后减;增大施工压力可增大储层改造体积,但增幅不明显。该模型为页岩储层体积压裂施工参数优选和改造体积预测提供参考。

The calculation model of the stimulated volume of shale reservoir volume fracturing is established based on the previous articles and field experience.The influences of elastic modulus,Poissons ratio,formation stress difference and reservoir thickness on the stimulated volume of shale reservoir volume fracturing would be studied based on the model.It is shown that Poissons ratio and formation stress difference have their optimal value,which are 0.36 and 6 MPa separately.when Poissons ratio and formation stress difference exceed their optimal value,fracturing fracture network is difficult to form.Case analysis shows that the stimulated volume of shale reservoir volume fracturing will increase with the increase of the flow rate of fracturing construction,but there is also optimal flow rate of 10m^3/min;the stimulated volume of shale reservoir volume fracturing will increase with the increase of the total volume of fracturing fluid,and its increment increases firstly and then decreases;the stimulated volume of shale reservoir volume fracturing will increase with the increase of fracturing pressure,but its increment is a little.This model can provide reference for the optimization of shale reservoir volume fracturing construction parameters and the prediction of the stimulated volume of shale reservoir volume fracturing.