【摘要】 为了研究井下控砂浓度实时混砂机理,借助现场压裂设备及井下混砂工具,开展了井下混砂工具地面物模试验研究。试验方案依据井下控砂浓度工艺原理设计,按照1∶1的比例进行全真模拟,并设计、制作了可视化模拟井筒试验装置,优选了试验参数和配套设施,采用现场压裂设备完成了携砂液性能和泵注设备能力测试以及井下混砂工具性能测试试验。试验结果表明,采用常规压裂机组,使用高黏度基液携砂,可实现110%超高砂质量浓度(1 800 kg/m~3)条件下稳定泵注,井下混砂工具旋流效果明显,混砂距离在0.6 m以内。试验还发现井下混砂工具的混砂距离随着油管排量及环空排量变化而变化。该试验为混砂机理研究和现场施工方案设计提供了依据。更多还原

【Abstract】 To study the real-time sand mixing mechanism of the downhole sand concentration control tool,a ground physical simulation of the downhole sand mixing tool has been conducted with the fracturing equipment and the downhole sand mixing tool. The experiment program is designed based on the downhole sand concentration control technology. The simulation is conducted on a full-size visual simulation wellbore device with optimized experimental parameters and auxiliary facilities. The fracturing equipment has been used to test the sand carrying fluid properties,as well as the pumping equipment capacity and downhole sand mixing tool performance. The results show that,with the conventional fracturing units and the use of high viscosity base fluid,steady pumping of slurry with 110% ultra-high sand concentration( 1 800 kg / m~3) can be achieved. The downhole sand mixing tool has an obvious swirling effect. The sand mixing distance is within 0. 6 m. It is also observed that the sand mixing distance varies with the tubing and annulus displacement. The experiment could provide basis for the sand mixing mechanism and field operation programma.更多还原