(n.) Drilling Fluids. A polymer or copolymer of an alkalene oxide, such as polyethylene glycol (PEG), a polymer of ethylene oxide with general formula HO(CH2CH2O)nH, or polypropylene glycol (PPG), which is a polymer of propylene oxide. PAGs are effective shaleinhibitors and have effectively replaced the earlier polyglycerols. Syn: TAME, thermally activated mud emulsion. Alt. form: polyalkalene glycol