【摘要】 在压裂、防砂及冲砂过程中 ,为防止砂粒在井筒底部沉积 ,需研究砂粒在液体中的沉降规律 ,从而确定最低排量等施工参数。根据固液两相流理论 ,推导了砂粒在牛顿流体、幂律流体及宾汉流体中不同沉降雷诺数范围内的沉降规律 ;用不同类型的液体及不同粒径的砂粒对不同情况下沉降规律进行了实验验证。实验及计算表明 :常用的斯托克斯公式仅适应于颗粒沉降雷诺数较小的情况 ;当砂粒较大、液体粘度较小时 ,用斯托克斯公式得出的计算值与实际值相差很大。新推导公式所得的理论计算值与实测值的误差较小 ,得出的砂粒沉降规律较为准确 ,可用于现场流体携砂能力的研究。更多还原

【Abstract】 In the process of fracturing, sand control and sand washing, settling rules of sand grain in the liquid should be studied, thereby to determine the minimum flow rate and other operation parameters in order to prevent sand deposit at the downhole. Based on the theory of solid?liquid two phase flow formulas have been derived which are used to calculate the settling velocity of sands in Newton fluid, power?law fluid and Bingham fluid at different settling Reynold number ranges. Settling rules under different conditions are verified experimentally by different types of fluid and sand with different grain diameters. The experiments and calculation indicate that the common Stokes formula is only suitable to the situation with small grain settling Reynold number. Otherwise there will be a large error between the value calculated by Stokes formula and the actual value under the condition of bigger sand grain and lower fluid viscosity. The error between theoretical value and measured one will be small and the obtained settling rules will be accurate if the newly derived formula is used. So it can be used to study the sand?carrying capacity of fluids in field.更多还原