Some stress components in a formation can be measured directly, and others can be derived from known quantities, but some must be estimated based on correlations.
地层的一些分应力可以直接测量，而且其它的可以从已知数推导，但是一些必须根据相互关系而估计。
2
Stress level is estimated at tens of MPa based on existing flow laws.
依据现有的流变学定律估算的流变应力应该在几十兆帕以上。
3
The limit stress of the material has been estimated.