# A Novel Efficient Borehole Cleaning Model for Optimizing Drilling Performance in Real Time
## 2 The Influence of Factors on Borehole Cleaning  
The aim of borehole cleaning and cuttings transportation is to prevent cuttings from settling and to facilitate their rapid transport to the shale shaker. In addition to serving as a coolant for the bit, the mud's primary role is to clean the drill bit face by removing and lifting cuttings away from it. Since the beginning of the studies on the cuttings transportation mechanism, one of the most important goals has been to obtain comprehensive knowledge about the process [28]. Identifying the specific factors affecting cuttings transportation is a difficult task as a single explanation that can satisfactorily explain all the gathered facts does not exist. However, a significant number of studies have arrived at the conclusion that the capacity of mud to transport rock pieces is dependent on the type of mud, its density and rheology, and the pace at which the mud flows or its annular velocity. In addition to the size and density of the cuttings, the borehole angle, RPM, ROP, and drill pipe eccentricity have an effect on cuttings transportation [10]. All the parameters that have an effect on cuttings transport are shown in Figure 2. As seen in Figure 2, it highlights the direct influence of variables such as borehole size and drilling fluid rheology, which can significantly enhance the cleaning process. However, there are also indirect factors, such as cutting size, density, shape, and the ROP, which can moderately impact borehole cleaning efficiency. Notably, certain variables can have a detrimental effect on the cleaning process. Inclinations, for instance, can pose a significant negative impact, making borehole cleaning efficiency difficult to achieve. On the other hand, there are factors that can significantly improve borehole cleaning conditions. Flow rate and RPM are examples of such variables, which can have a significant positive effect and optimize the cleaning process. It is therefore important to consider all the factors that can influence borehole cleaning conditions in order to achieve the best possible results [10; 19]. In addition to these affects, the settling velocity of cuttings in drilling fluids is influenced by several parameters, including cuttings size, shape, and density, as well as drilling fluid density, viscosity, and velocity. Cuttings that are larger, denser, or irregularly shaped tend to settle more quickly than smaller, less dense, or rounded cuttings. The density of the drilling fluid plays a critical role in controlling the settling velocity of the cuttings, with higher density fluids suspending larger and denser cuttings more effectively [9; 10]. The viscosity of the drilling fluid affects the drag force on the cuttings, slowing down  
Figure 1: The flowchart outlining the various topics discussed and the systematic order in which they are presented. their settling velocity, while the fluid velocity can affect cuttings suspension. The wellbore configuration and presence of confining walls, such as casing or formation, can also affect the settling velocity of cuttings. Finally, pipe rotation can create turbulence in the drilling fluid, helping to suspend the cuttings and reduce their settling velocity [9; 29]. Moreover, this demonstrates that the eccentricity of the drill pipe has an indirect influence on cutting transport, but the size of the borehole, the characteristics of the mud, the amount of cuttings, and the flow rate all have direct impacts on the optimization of borehole cleaning. For example, when used in conjunction with other factors, rotation can boost borehole cleaning effectiveness even more (see Figure 3) [19; 30; 31]. Rotating the drill pipe can improve borehole cleaning by combining the rheology of the mud, the size of the cuts, and the flow velocity of the mud. Additionally, the dynamic behavior of the drill pipe, such as steady-state vibration, unsteady-state vibration, whirling rotation, and true axial rotation parallel to the borehole axis, can have a substantial impact on improving borehole cleaning.