1. n. [Drilling Fluids]
A nonionic starch derivative, analogous to hydroxyethylcellulose in its method of manufacture and most applications for drilling, workover and completion fluids. Rather than using a cellulosic starting material, such as hydroxyethylcellulose (HEC), starch is used instead, and reacted with ethylene oxide in an alkaline environment.
Alternate Form: hydroxyethyl starch
See: saltwater mud