Pores and Microanalysis of Microbe-Inspired Nano-CaCO₃ Cementing Sand Columns

Table 2

Permeability grades of rocks.

Grades	1	2	3	4	5	6	7
Permeability	Super high	Very high	High	Medium	Low	Very low	Super low
Permeable area/10^−3 𝜇m^2	>1000	1000~500	500~100	100~50	50~10	10~1	<1