Corrosion Rings and Coupons - OFI Te
grams per square meter per year, or in mils per year (metal loss in thou-hs of an inch per year). A nominal fee is charged for this service. It should be noted that the loss of metal is due to both corrosive and ero-sive effects of the drilling fluid, since the bore of the ring is exposed to the fluid pumped down the drill string.