DRILLING FLUID MODIFIER AND DRILLING FLUID USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a drilling fluid modifier using a PVA resin which can contribute to suppression of hydration and swelling of bentonite even under existence of salts, and to provide a drilling fluid using the same.SOLUTION: There is provided a drilling fluid modifier containing a PVA resin containing a 1,2-diol structural unit in a side chain which is excellent in solubility under coexistence of salts such as a potassium ion, and is also excellent in suppression of hydration and swelling of bentonite.