滑溜水压裂支撑剂在水平井筒内沉降规律研究

Study on settlement law of proppant within horizontal wellbore in slickwater fracturing

为了研究支撑剂在水平井水平段内沉降规律,自主设计了实验装置及实验方法,分别研究了水平井直径、排量、砂比、压裂液黏度等参数对临界沉降速度和临界再悬浮速度的影响。实验结果表明:支撑剂的临界沉降速度和临界再悬浮速度随着砂比、水平井直径的增大而增大,随着压裂液黏度的增大而减小;临界速度受水平井筒直径、压裂液黏度影响较大,受砂比影响较小;在相同条件下,临界再悬浮速度比临界沉降速度大。基于实验数据,通过多元非线性拟合,建立了临界速度计算模型,该模型考虑了支撑剂、压裂液、水平井直径、砂比等影响因素,能较准确预测临界沉降速度和临界再悬浮速度。

In order to understand the settlement law of proppant in horizontal wellbore,the effects of horizontal wellbore diameter,fracturing liquid flow rate,sand content and fracturing fluid viscosity on the critical settling velocity and the critical resuspension velocity of proppant are studied using self-designed experiment unit and method. The experimental results show that the critical settling velocity and the critical resuspension velocity increase with the increase of sand content and horizontal wellbore diameter,and they decrease with the increasing of fracturing fluid viscosity. The horizontal wellbore diameter and the fracturing fluid viscosity has great influence on the critical settling velocity,while the influence of sand content on the critical settling velocity is little. Under the same conditions,the critical settling velocity is greater than the critical resuspension velocity. Based on the experimental data,a critical velocity prediction model is established through multivariate nonlinear fitting. The influences of proppant,fracturing fluid,horizontal wellbore diameter and sand content on the critical velocities are considered in the model,so this model can accurately predict the critical settling velocity and the critical resuspension velocity.