Abstract In oil and gas exploration and development, drilling a hole is one of the first and most expensive operations. The continuous demand from industry to reduce costs and operational problems has resulted in numerous innovative drilling technologies that allow us to drill directionally. Nevertheless, hole cleaning has become a problematic issue in directional drilling because drill cuttings tend to be deposited on the lower side of the deviated hole. Excess accumulation of cuttings significantly reduces the rate of penetration and indirectly increases the operational cost. To improve the cuttings transport efficiency in a deviated hole, low-density polyethylene (LDPE) beads were introduced into water-based mud for hole cleaning. LDPE beads travel rapidly through the mud column due to buoyancy and move the cuttings forward by drag and collision. The interaction between the LDPE beads and cuttings facilitates the cuttings transport process and prevents the cuttings from settling. In this study, different concentrations of LDPE beads (i.e., 1% to 5% by volume) and different flow rates (i.e., 0.4 L/s, 0.6 L/s, and 1.0 L/s) were used to determine the effects on cuttings transport efficiency. In addition, the hole angle was varied from vertical to horizontal to evaluate the significance of LDPE beads in assisting in transporting cuttings. The results denote that more cuttings can be removed from a hole with higher concentrations of LDPE beads in water-based mud. This finding is due to the higher frequency of collisions, which in turn produces larger impulsive force. In addition, the improvement in cuttings transport efficiency enabled by LDPE beads is more significant in a vertical hole than in a highly deviated hole. In summary, LDPE beads are a promising additive for drilling mud to effectively remove drilled cuttings from a hole.

中文翻译：

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在不同孔角的不同泥浆循环率下使用低密度聚乙烯珠改善孔清洁

摘要 在油气勘探开发中，钻孔是首要的也是最昂贵的作业之一。行业对降低成本和运营问题的持续需求导致了许多创新的钻井技术，使我们能够进行定向钻井。然而，在定向钻井中，井眼清洁已经成为一个问题，因为钻屑往往会沉积在斜孔的下侧。钻屑过多堆积会显着降低渗透率并间接增加运营成本。为了提高斜孔中岩屑的输送效率，在水基泥浆中加入低密度聚乙烯 (LDPE) 珠进行井眼清洁。LDPE 珠子由于浮力而快速穿过泥柱，并通过阻力和碰撞将岩屑向前移动。LDPE 珠粒和岩屑之间的相互作用促进了岩屑运输过程并防止岩屑沉降。在本研究中，使用不同浓度的 LDPE 珠粒（即 1% 至 5% 体积）和不同流速（即 0.4 L/s、0.6 L/s 和 1.0 L/s）来确定对岩屑运输效率。此外，孔角度从垂直到水平变化，以评估 LDPE 珠在协助运输岩屑方面的重要性。结果表明，在水基泥浆中 LDPE 珠浓度较高时，可以从孔中去除更多钻屑。这一发现是由于碰撞频率较高，进而产生较大的冲击力。此外，LDPE 珠对岩屑输送效率的提高在垂直孔中比在大斜度孔中更为显着。总之，低密度聚乙烯珠粒是一种很有前途的钻井泥浆添加剂，可以有效地从孔中去除钻屑。