Abstract Transportation of drilled cuttings from the bit to the surface is one of the primary functions of a drilling fluid. This transport is facilitated primarily by pump rate and the rheology and density of the drilling fluid, which all contribute to cuttings lift. There are, however, other important factors that have a significant effect on cuttings transport, as shown by a large amount of academic and industry research. These include rotation and the eccentricity of the drillstring. These two parameters are interrelated when it comes to hole cleaning: the effect of pipe rotation on cuttings evacuation changes with varying eccentricity. This adds a level of complexity to the hole cleaning challenge, both from a modeling perspective as well as the practical management of cuttings evacuation from wells in the field. A novel cuttings transport model that includes essential effects such as pipe rotation, eccentricity and annulus blockage is presented in this study. Velocity profiles for the well annulus subdivided into small grids are calculated for any given fluid, which can be a Newtonian or a non-Newtonian fluid such as described by the Bingham Plastic, Power Law or Yield Power Law rheological models. These local velocities are compared against the concept of the critical velocity for cuttings transport. Then, the locations of the settled cuttings and the magnitude of annular blockage are calculated numerically. Continuity and momentum equations are solved for the blocked annulus to estimate the new local velocities. By doing so, a realistic representation of a wellbore’s pressure and velocity profiles is obtained. The work aims to make hole cleaning modeling more comprehensive and representative in order to prevent hole cleaning-related non-productive time (NPT) or invisible lost time (ILT) events in the field. These include stuck pipe and lost circulation events, low rates of penetration, high torque and drag, failure to land the casing at the desired depth, and poor cement jobs leading in turn to poor zonal isolation.

中文翻译：

---

模拟钻柱偏心、管道旋转和环形堵塞对斜井中钻屑输送的影响

摘要 将钻屑从钻头输送到地面是钻井液的主要功能之一。这种输送主要是由泵速以及钻井液的流变性和密度促进的，这些都有助于岩屑提升。然而，大量学术和行业研究表明，还有其他重要因素对岩屑运输有显着影响。这些包括钻柱的旋转和偏心度。这两个参数在井眼清洁方面是相互关联的：管道旋转对岩屑排出的影响随着偏心距的变化而变化。这增加了井眼清理挑战的复杂性，无论是从建模角度还是从现场井中排出钻屑的实际管理。本研究提出了一种新的岩屑传输模型，其中包括管道旋转、偏心和环空堵塞等基本效应。针对任何给定流体计算细分为小网格的井环空的速度剖面，该流体可以是牛顿流体或非牛顿流体，例如宾汉塑性、幂律或屈服幂律流变模型所描述的。将这些局部速度与岩屑输送的临界速度概念进行比较。然后，数值计算了沉降岩屑的位置和环形堵塞的大小。求解阻塞环的连续性和动量方程以估计新的局部速度。通过这样做，可以获得井眼压力和速度剖面的真实表现。该工作旨在使孔清洁建模更加全面和具有代表性，以防止现场与孔清洁相关的非生产时间 (NPT) 或隐形损失时间 (ILT) 事件。这些包括卡住管道和漏失事件、低渗透率、高扭矩和阻力、未能将套管降落在所需的深度以及水泥作业不当，进而导致区域隔离不良。