HYDRAULIC FLUIDS FOR BOP CONTROL SYSTEMS.

This paper discusses the development, application, and selection of hydraulic fluids that activate controls of blowout preventer (BOP) systems. The proper criteria for selecting hydraulic fluids are discussed and evaluated: lubricity, corrosion inhibition, biodegradability, toxicity, and stability in fresh and salt water. New data comparing three laboratory tests for lubricity leads the author to conclude that lubricity is overemphasized as a primary criterion for selecting hydraulic fluids. Corrosion inhibition should receive more emphasis since most products are formualted to provide a minimum level of protection, but usually not enough for thorough inhibition. In addition to laboratory procedures and test data on lubricity and corrosion inhibition, procedures and data on toxicity and on stability in fresh and salt water for each major type of fluid are presented.