Specific gravity effect of slurry and adjustment

Specific gravity is the most important control index of the mud, its size is mainly determined by the solid phase content of the mud and the specific gravity of the solid phase, solid phase content is the weight or volume percentage of solid particles in the mud. We know that different specific gravity sizes form different pressures and pressures.

The specific gravity of the mud will play a corresponding role in mud wall protection and support, the greater the specific gravity the greater the pressure and pressure, the greater the support of the mud on the perimeter wall, and from that perspective alone, for areas with poor formation stability, the specific gravity of the mud will be relatively controlled to achieve the stabilization effect. But the specific gravity is too large, which means that the useless solid phase content in the mud is too high, not only easy to cause thickening of the mud skin, rheological properties will also be lost, resulting in increased pressure pressure of filling, injection will seem more difficult.

Therefore, in different application scenarios, the specific gravity of the mud needs to be designed and, if necessary, the mud needs to be weighted. The commonly used weighting materials are prepared by grinding and processing inert materials that are insoluble in water. Weighting materials should have the conditions of high density, low abrasiveness, easy to crush, and do not interact with other components of the mud. The commonly used weighting materials in the industry are barite powder, perlite, etc.

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Barite powder

But it should be noted that the traditional bentonite slurry slurry making process, viscosity and specific gravity is basically positive correlation, the impact on the construction of the same general trend, while some special chemical slurry is different from it, its often through a very small amount of chemical additives, improve the viscosity of the slurry, due to the small amount of additive, so the specific gravity is almost no change, but the viscosity growth also plays the role of wall protection and support, which is its characteristics. Translated with www.DeepL.com/Translator (free version)

New thixotropic slurry

The new thixotropic mud developed by us, BSI, is closer to a chemical mud, where the molding state of the bentonite mud is adjusted by a very small amount of additive admixture to provide support or lubrication. In order to respond to different needs and adapt to different working conditions, we have also started to study the way of adjusting its specific gravity. This is so that it can be widely used in various shield, pipe jacking, vertical shaft and other work methods. We also look forward to the application and communication with the general industry.