Over the years, barite (BaSO₄) as weighting agent was widely used. However, it has an issue with particles settling which is known as barite sagging, that causes a variation in drilling fluid properties and operational problems. This study introduces and investigates a novel combination of Micromax (Mn₃O₄) and barite weighting materials to prevent the barite sagging in water-based mud under high pressure high temperature (HPHT) situations. Different amounts of Micromax, 0, 25 and 50 wt% from the total weighting material were added to the field formula. Static and dynamic sagging tests were conducted at 250 °F and 120 °F, respectively, to study the sagging tendency and identify the optimum combination. The mud pH and density were measured at ambient conditions. The rheological properties measurements were conducted at 120 °F and 250 °F. The filtration properties were evaluated using HPHT filtration test at 300 psi and 250 °F. The results showed that adding 25/75 wt% Micromax/barite is enough to eliminate the sag issue in both vertical and 45° inclined position, as it enforced the sagging tendency to the safe range. The 25/75 wt% Micromax/barite has no significant effect on the rheological properties compared to the 100 wt% barite, except for the 30 min gel strength which was increased by 19% for better particles suspension while no circulation. The HPHT filtration test indicated a significant decrease in the filter cake thickness and weight with the 25/75 wt% Micromax/barite without significant change in the filtration volume compared to the 100 wt% barite.

多年来，重晶石（BaSO ₄）作为增重剂被广泛使用。但是，这存在颗粒沉降的问题，这称为重晶石下垂，其导致钻井液性质的变化和操作问题。本研究介绍并研究了Micromax（Mn ₃ O ₄）和重晶石加重材料，以防止在高温高压（HPHT）情况下水基泥浆中的重晶石下垂。将占总称重材料不同数量的Micromax，0、25和50 wt％添加到现场配方中。分别在250°F和120°F下进行了静态和动态下垂测试，以研究下垂趋势并确定最佳组合。在环境条件下测量泥浆的pH和密度。流变性质的测量是在120°F和250°F下进行的。使用HPHT过滤测试在300 psi和250°F下评估过滤性能。结果表明，添加25/75 wt％的Micromax /重晶石足以消除垂向和45°倾斜位置的垂度问题，因为它使垂度趋于安全范围。与100％（重量）的重晶石相比，25/75％（重量）的Micromax /重晶石对流变性能没有显着影响，除了30分钟的凝胶强度提高了19％，以实现更好的颗粒悬浮而没有循环。HPHT过滤测试表明，与100 wt％的重晶石相比，使用25/75 wt％的Micromax /重晶石，滤饼的厚度和重量显着降低，而过滤体积没有明显变化。