## 3 Results  
### Sag Test  
Figure 8 depicts static results of barite sag propensity in the absence of fly ash at 250 \({}^{\circ}\)F, 300 \({}^{\circ}\)F, 350 \({}^{\circ}\)F, and 400 \({}^{\circ}\)F under various inclinations of 30\({}^{\circ}\), 45\({}^{\circ}\), 60\({}^{\circ}\), 70\({}^{\circ}\), 80\({}^{\circ}\), and 90\({}^{\circ}\). At 250 \({}^{\circ}\)F, which is the lowest temperature at which the static sag was examined, the lowest SF was obtained for all inclinations. A sharp increase in SF was observed to have started from 45\({}^{\circ}\) to 62\({}^{\circ}\). This trend seems applicable to all other temperatures and inclinations. Noticeably, from 45\({}^{\circ}\) to 62\({}^{\circ}\), at 250 \({}^{\circ}\)F, 300 \({}^{\circ}\)F, 350 \({}^{\circ}\)F, and 400 \({}^{\circ}\)F, a percentage increase of 2.9, 1.91, 1.71, and 1.51% respectively was noticed. This shows that the highest increase in SF of 2.9% occurred between 45\({}^{\circ}\) and 62\({}^{\circ}\) at 250 \({}^{\circ}\)F. However, this may be traceable to the severe impact of 17\({}^{\circ}\) (62\({}^{\circ}\)-45\({}^{\circ}\)) increase in hole inclination on the base fluid sample at 250 \({}^{\circ}\)F. Also, it was noticeable that the base fluid's SF exceeded the safe boundary at 250 \({}^{\circ}\)F, 300 \({}^{\circ}\)F, 350 \({}^{\circ}\)F, and 400 \({}^{\circ}\)F, while exhibiting sagging tendencies from 58\({}^{\circ}\), 55\({}^{\circ}\), 52\({}^{\circ}\), and 46\({}^{\circ}\) accordingly. This may be due to the inability of the base fluid to withstand thermal stability in these situations. Afterward, the sagging disappeared at 63\({}^{\circ}\), 65\({}^{\circ}\), 73\({}^{\circ}\), and 78\({}^{\circ}\) for the respective test temperatures. Deductively, it may be said that the higher the static sag test temperature, the sooner the barite sag may occur, and vice versa. The highest SF exhibited by all the test temperatures was 62\({}^{\circ}\), which for this study may be referred to as the notorious angle of inclinations. This may be due to the intense influence of hole deviation (62\({}^{\circ}\)) on the drilling fluid additives and temperatures. The principle of settling and the surface area of the hole may be applicable to explain barite sagging. A vertical wellbore has a smaller surface area as compared to an inclined wellbore; hence, the particles are closely packed in the wellbore column. Due to gravity differences, the particles tend  
Figure 7: Static sag testing apparatus: (**a**) inclined (30\({}^{\circ}\), 45\({}^{\circ}\), 60\({}^{\circ}\), 70\({}^{\circ}\), 80\({}^{\circ}\), and 90\({}^{\circ}\)) and (**b**) vertical. (**c**) The major apparatus for the VSST test (syringe not included). to settle out of the column, but the effect of hindered settling prevents the free settling of particles. A falling particle may be hindered by a suspended particle, thereby mitigating the settling rate. Conversely, when the wellbore is more inclined, the surface area increases, and particles become sparsely populated. Hence, free settling is initiated, which may increase the settling rate. Consequently, there is a dominance of free settling in deviated wells [7]. In addition, the effect of free settling may be most acute at 62\({}^{\circ}\), due to the high SF experienced at this inclination. Figure 9 displays the positive impact of 3 lb/bbl of fly ash on Fluid 3. The trend is similar to the trend of the base fluid (without fly ash), apart from a sudden hike in SF from 45\({}^{\circ}\) to 63\({}^{\circ}\) inclinations. As compared with the base fluid, a smooth trend of percentage increase in SF of 0.20, 0.77, 0.38, and 0.38% occurred between 45\({}^{\circ}\) to 63\({}^{\circ}\) inclinations at 250 \({}^{\circ}\)F, 300 \({}^{\circ}\)F, 350 \({}^{\circ}\)F, and 400 \({}^{\circ}\)F, respectively. The influence of the notorious angle (63\({}^{\circ}\) inclination) on Fluid 3 did not cause a devastating increase in SF, which may be due to the presence of fly ash as opposed to the base fluid without fly ash.