Based on the fissure development characteristics ofexpansive soils, water well drilling rig.borehole wall stability requires dual measures of “anti-swelling + anti-shrinkage”:
Chemical borehole protection: Inject sodium silicate solution (modulus 3.2) to react with clay and form a waterproof film.
Physical support: Use double-layer casings (outer protective casing + inner screen pipe), filling expansion water-stop strips in the gap.
Humidity control: Circulate low-temperature mud (10–15℃) in the hole to reduce water migration.water well drilling rig
