Abstract: Polyamine water-based drilling fluid is considered to be of high performance and most close to the properties
of water-based invert emulsion mud developed in recent years. Because of the unique molecular structure and outstanding
inhibition，the new polyamine shale inhibitor has been showing more and more attention. The inhibitive properties between
polyamine and potassium chloride are evaluated by bentonite inhibition test，buckle hardness test，shale hot-rolling dispersion
test，slake durability test，shale linear swelling test and the interlayer spacing measurement and so on. The results indicate that，
compared to potassium chloride，polyamine can suppress clay hydration and dispersion with low concentration but long effect.
Also polyamine exhibits high temperature resistance. Compatibility tests indicate that polyamine is compatible with bentonite
and common additives. Based on SDA，polyamine water-based drilling fluid is developed. The experiments demonstrate that
the system shows high performance of anti-salt，anti-calcium and anti-cuttings pollution.

Key words: polyamine, potassium chloride, inhibition, clay hydration, wellbore stability