Test results show that: viscosity comparison, nano-calcium > heavy calcium carbonate > low oil-absorbing activated calcium. 1, generally the finer the powder, the higher the oil-absorbing value, the higher the viscosity, by the nano-calcium particle size between 60-100nm, has an excellent thickening effect, can effectively improve the stability of the fluid; 2, at the same time, as can be seen above, low oil-absorbing active calcium viscosity rate slower than the heavy calcium carbonate, that is, in the same proportion of its viscosity is smaller, and the other by the right figure can be seen in the high proportion of low oil-absorbing active calcium in the addition of a certain amount of shear viscosity effect, similar to the rheological properties of talcum powder, with the production and construction of a friendly features; 3、At the same time, generally with the different additive ratio of the powder filler, the system viscosity will also appear different changes, the follow-up Division I will start a new share for this.