During the drilling of shale gas wells, the shape of shale cuttings cut by polycrystalline diamond compact bits has an obvious flaky structure. The accumulation of such flaky cuttings is one of the main reasons for high drilling torque and drag and serious back pressure, which affect the drilling speed of the horizontal section of shale gas wells. Therefore, predicting the thickness of the flaky cuttings bed and restraining it are essential for ensuring safe and efficient drilling of the horizontal section of shale gas wells. However, most of the previous research on migration laws for cuttings were based on spherical particles, which affected the accuracy of cuttings bed thickness prediction. In this study, through visualization experiments combined with computational fluid dynamics numerical simulation, the hole cleaning laws of shale gas wells in the long horizontal section were studied, and a set of cuttings bed thickness prediction models and cuttings bed removal process parameter optimization methods were established. Field application was conducted in the Changning 209H24-1 well in the southern Sichuan Basin, China. The results revealed the following: (1) There are significant differences in the migration laws of flaky cuttings and spherical cuttings in the horizontal section. (2) The fitting accuracy of the established long horizontal fragmentation layer distribution model considering multiple factors and the experimental data is as high as 0.973. (3) Based on this model, the drilling parameters of the Changning 209H24-1 well were optimized, which played a good role in wellbore cleaning and ensured the safe and smooth implementation of the later casing operation.

在页岩气井钻井过程中，多晶金刚石复合钻头切割的页岩岩屑形状具有明显的片状结构。这种片状岩屑的堆积是造成钻井扭矩大、阻力大、背压严重的主要原因之一，影响页岩气井水平段的钻井速度。因此，预测片状岩屑层厚度并对其进行约束，对于保证页岩气井水平段安全高效钻井至关重要。然而，以往对岩屑运移规律的研究大多基于球形颗粒，影响了岩屑层厚预测的准确性。本研究通过可视化实验结合计算流体动力学数值模拟，研究了长水平段页岩气井的清孔规律，建立了一套岩屑层厚度预测模型和岩屑层清除工艺参数优化方法。在四川盆地南部的长宁209H24-1井进行了现场应用。结果表明：（1）水平剖面片状岩屑和球形岩屑的运移规律存在显着差异。(2) 建立的考虑多因素和实验数据的长水平破碎层分布模型的拟合精度高达0.973。(3) 基于该模型，优化了长宁209H24-1井的钻井参数，