## 1 Introduction  
Directional drilling, particularly in high-temperature environments, presents a unique set of challenges, one of which is the phenomenon of weight material sagging in the drilling fluids. The ability of drilling fluids to effectively suspend weight materials is paramount for the success of drilling operations. Weight materials that settle out of the fluid column not only cease to contribute to hydrostatic pressure but also have the potential to induce fluctuations in hydrostatic pressure. The inadequate design of drilling fluids to address sagging issues can lead to significant drilling challenges, including insufficient mud density, which in turn may result in critical issues such as compromised well control, pipe sticking, downhole mud losses, and even formation fractures. Thus, understanding and effectively managing weight material sag in deviated drilling operations is imperative for ensuring drilling efficiency, safety, and overall project success. Sag occurs when the weight material settles out of the drilling fluid, leading to fluctuations in mud density and hydrostatic pressure. This phenomenon is observed in both vertical and inclined well positions, as well as in static and dynamic conditions, although it is more prevalent under dynamic conditions with low shear rates. Several factors contribute to sag, including particle size distribution, densifying material, subsurface temperature, fluid density, type of fluid, reduced fluid flow, and wellbore configuration. Numerous techniques have been adopted in previous studies to understand and simulate the sagging phenomena. [PERSON] et al. [1] suggested measuring fluid density at the surface by capturing the density of returning fluid when making or coming out of a hole. Practical simulation and prediction of barite sag under stable and dynamic conditions have been studied using different approaches including flow-circuit experimental setups, a Viscometer Sag Shoe Test (VSST), and a form of sag envelope apparatus setups. Flow properties and viscoelastic data obtained from viscometers are used in a distinct technique for detecting barite sag, correlating the obtained sag data with sag propensities. Magnetic and acoustic methods have been applied to study sagging tendencies by noting the density difference in the data obtained from both principles. An innovative approach by [PERSON] et al. (2018) involved using a stability analyzer with a light source to scan drilling fluids under static and dynamic conditions. The dynamic and static settings were studied using a rheometer and an optical scanning apparatus. The settling rates of solids and stability were characterized by applying the modified Stokes law of settling, while the dynamic data were reported by comparing the shear rates between oscillatory and rotational conditions. To address this persistent issue, reduction in the particle size of the weight material and the combination of weighting agents have been explored as alternative ways to lower the settling rate and increase the solid particle suspension. [PERSON] and [PERSON] (2018) proposed the use of a high-angle sag tester (HAST) instrument that may identify sag susceptibility by changing the location of the test fluid's center of mass at temperatures up to 300 \({}^{\circ}\)F and inclination angles between 20\({}^{\circ}\) and 90\({}^{\circ}\). The outcomes show that the data on the viscosity measurement of drilling muds are not accurate for estimating sag behavior in extended-reach well drilling. The angle of borehole inclination during drilling, as an important parameter in the study of barite sagging, was explored by [PERSON] et al. (2018). The outcome showed that the highest sag factor ranged from 60\({}^{\circ}\) to 75\({}^{\circ}\), often occurring at reduced annular velocities. They asserted that drill stem rotation has been shown to be particularly helpful in minimizing barite settling.