水力压裂低密度支撑剂铺置规律研究及应用

水力压裂过程中支撑剂在裂缝中铺置情况对增产效果的影响很大。研究低密度支撑剂在清水、0.08% HPG基液、0.3% HPG基液3种不同黏度的流体介质在不同排量（分别为1、2、4、6 m3/h）、不同砂比（5%、10%、15%、20%）条件下的砂堤铺置形态。通过线性拟合计算发现，随着排量增大，支撑剂的水平运移速度增大，垂直运移速度减小，支撑剂在沉降过程中出现“波动”状态；当缝口流速较小时（不大于0.5 m/s），支撑剂水平运移速度增长量较快；缝口流速较大时（大于0.5 m/s），支撑剂水平运移速度增长量减缓。目前已完成3口井低密度支撑剂现场应用试验，平均无阻流量为28.015×104 m3/d，是常规井的1.91倍，对现场施工具有良好的指导作用。 

Study on Distribution of Low Density Proppants in Hydraulic Fracturing Operations and the Application Thereof

In hydraulic fracturing operations, the distribution of proppants in the fractures play an important role to the results of the stimulation job. Laboratory experiments have been conducted to study the distribution of settled sand bank of low density proppants in fresh water, in 0.08% HPG solution and 0.3% HPG solution, three solutions with different viscosity, at different flowrates (1, 2, 4 and 6 m3/h, respectively) and different sand/liquid ratios (5%, 10%, 15% and 20%, respectively). Calculating of the experimental data with linear fitting showed that the horizontal migration velocity of the proppants increases with flowrate of the liquid, contrary to the vertical migration speed of the proppants. A "fluctuation" phenomenon was observed during the settling of proppant. At low flowrate (less than or equal to 0.5 m/s) of the liquid at the opening of a fracture, the horizontal migration velocity of proppants is increasing fast. At high flowrate (greater than 0.5 m/s) of the liquid at the opening of a fracture, the increase of horizontal migration velocity of proppants is slow down. Field test have been done on three wells using low density proppants, the average open-flow capacity was 28.015×104 m3/d, 1.91 times of the flowrate of offset wells. The test results provide good guidance to hydraulic fracturing operations.