What are the causes of shrinkage during drilling
After the formation of the hole, the plastic deformation and the hole diameter are easy to occur after the formation of the borehole
The sandstone reservoir with high porosity and high permeability, the water loss of the mud is large, and it is easy to form a thick mud cake on the wall.
In the well section with high clay mineral composition, the water absorption of clay is caused by water swelling
