| 摘要 |
A tubular threaded joint for connecting tubing or casing used to excavate oil wells have a lubricating coating formed from a lubricating coating composition comprising one or more basic lubricants selected from a basic sulfonate salt, a basic salicylate salt, a basic phenate salt, and a basic carboxylate salt and having biodegradability value (BOD) of at least 20% when measured after 28 days in seawater. The joint can be used without application of a compound grease containing heavy metals even in a country or region having severe environmental regulations. |
