钻井岩屑粒径分布规律的研究

钻井振动筛是固控系统的重要分离设备,其主要任务是清除钻井液中直径大于74μm的固相颗粒。对辽河油田7口井深0～3500m的钻井岩屑进行了实地取样,分析了岩样颗粒直径大于74μm的粒径分布特征。分析结果表明,钻井岩屑具有明显的片状特征,颗粒的粒径分布主要与地层岩性和破岩工具有关,随着井深的变化,其岩样粒径分布呈现出幂分布、2分布和瑞利分布等3组典型规律。给出了岩屑颗粒的概率直径;建议在筛面颗粒运动特性研究、筛网工作载荷的计算和激振方式的选择中,应考虑岩屑颗粒片状特性的影响。

Study of the size distribution of drill cuttings

Shale shaker is one of the important separating facilities in solids controlling system for eliminating the particles with a diameter of over 74 μm.The samples of rock cuttings are taken from 7 wells with the depth of 0~3 500 m in Liaohe Oilfield.The size distribution characteristic of the sample particles with the diameter over 74 μm is analyzed.The conclusion shows that the drill cuttings feature obvious sheet structure and the size distribution of the particles is mainly related to the formation lithology and drilling tools.The size of rock cuttings displays 3 kinds of typical distribution rules with the well depth change.The probability diameter of the cutting particles is provided.It is suggested that the effect of the sheet feature of the cutting particles should be considered in studying the motion feature of screen-surface particles,calculating the working load of screen grid and selecting the exciting methods.