AQUEOUS WELL DRILLING FLUIDS

摘要

A method and composition for decreasing the fluid loss of aqueous well servicing fluids in which an additive comprised of a cross-linked hydroxyethyl starch and a polymeric component such as a carboxyalkyl cellulose ethers or xanthan gum is added, in effective amounts, to the aqueous fluid, the aqueous fluid preferably being one which contains at least one water soluble salt of a multi-valent metal ion.