HYDRAULIC FLUID COMPOSITIONS

摘要

The invention claims a novel hydraulic fluid composition for application to drilling equipment. These hydraulic fluid compositions permit effective monitoring or controlling of well-head pressure in a well during drilling on land or offshore. Accordingly, provided is a hydraulic fluid concentrate which contains a water-soluble phosphate ester and a sulfide compound containing at least one S-S linkage, at least 10 carbon atoms and at least one terminal carboxylate group, wherein the S-S linkage bridges two alkyl groups. Particularly, these. compositions have low toxicity to sea life and are effective in reducing seawater corrosion of a metal and reducing bioaccumulation in oil drilling equipment.