基于坐封受力模型的暂堵球封堵效果影响因素与参数优化

暂堵球在射孔孔眼及压裂裂缝中的坐封状态影响其封堵稳定性,暂堵球封堵效果决定暂堵转向压裂技术的成败。通过建立暂堵球坐封受力计算模型,研究了压裂液排量、密度、暂堵球及孔眼参数对暂堵球坐封受力状态及其封堵效率的影响,实验模拟了不同射孔参数、压裂排量及暂堵球/压裂液性能对封堵效果的影响。结果表明：暂堵球受拖拽力、脱离力及持球力随压裂液排量的增加而增大,暂堵球更易坐封;压裂液及暂堵球密度对暂堵球坐封封堵效率影响不大;暂堵球粒径大于孔眼直径时,暂堵球坐封封堵效率随粒径增加而增大,当暂堵球直径小于孔眼直径时,暂堵球不容易坐封;射孔孔眼数增加影响暂堵球坐封封堵效率。实验评价暂堵球最佳直径为9.0mm,最佳泵送排量＞4.0 m3/min,有助于提高暂堵球坐封成功率,增强暂堵压裂设计的可靠性。

Influence Factors and Parameter Optimization of Plugging Effect Based on the Set-up Force Model of the Temporary Plugger

The success or failure of the temporary plug fracturing technique is determined by the plug effect of the temporary plug. Therefore, the setup state of the temporary plug agent during perforation and fracture affects its plug stability. Based on an established force model for temporary plugs in horizontal sections, this study evaluates the impact of fracture fluid displacement, density, temporary plug and hole parameters on the force of temporary plugs and their setup efficiency. It was shown that the drag, detachment and ballast forces of the temporary plug increase with the displacement of the fracturing fluid, making it easier to establish the temporary plug. The density of the fracturing fluid and the temporary caulk had little effect on the setup efficiency of the temporary plug. When the particle size of the temporary plug is larger than the hole diameter, the setup efficiency of the temporary plug increases with the particle size. However, if the diameter of the temporary plug is smaller than the diameter of the hole, it cannot be easily set. The increase in the number of holes affects the setup efficiency of the temporary plug. The experimental evaluation shows that the optimal diameter of the temporary plugging ball is 9.0mm, and the optimal pumping displacement is greater than 4.0 m3/min, which helps to improve the success rate of the temporary plugging ball setting and enhance the reliability of the temporary plugging fracturing design.