ABSTRACT
TAN: See Total acid number. Tangential Stress (Tubing): Stresses around the body of the tubing (hoop stresses). Tangential Wave: An S wave. Tangible Costs (Drilling): Items of well construction that have salvage value, ordinarily capitalized on taxes. Tank: (1) An articial container in which liquids are held or detained. (2) A number of petroleum tanks that are operated together as a depot in oil storage and distribution activities. Tank Battery: A group of tanks at a well site used to store oil prior to sale to a pipeline company. Tank Bottoms: (1) The oil in a tank below the level of the outlet pipe. (2) The near solid or highly viscous residuals at the bottom of an oil storage tank, generally composed of a large amount of parafns, silt, heavy ends, etc. Tankers: Used to transport crude oil and rened products in waterborne trade. The tankers can be used in either “clean” (light rened products such as gasoline and diesel fuel) or “dirty” (residual fuel and crude oil) trade. The tankers range in size from the small vessels used to transport rened products to huge crude carriers. Tanker sizes are expressed in terms of deadweight tons (dwt). The smallest tankers are General Purpose that range from 10 to 25,000 tons and the largest are. Tankers are unloaded/loaded at the jetties or the specially built piers. Tank Farm: An installation used by gathering and trunk pipeline companies, crude oil producers, and terminal operators (except reneries) to store crude oil. TAP: Trapped annular pressure. Tap: A valve on a line. Tapered Bowl: A two-piece tting placed in the master bushing to hold the slips. Tapered Mill: A mill with a gradual concave or convex taper designed to enlarge the wellbore. Tapered String: A tubing string with more than one tubing size. Normally the smallest pipe is on the bottom with larger sizes toward the top. The sizes are set to minimize ¤owing friction and keep the velocity above the critical level to lift ¤uid. Taper Tap: A spear-like shing device with threads to engage ID threaded sh. Tar: A deposit of very long carbon chain alkanes. May be associated with asphaltenes. Target (Risk): A preferred outcome from an activity. Tariff Gas: Additional natural gas sold to a customer if the total amount of natural gas needed exceeds their original estimate. Tar Sands: A deposit of heavy oil, usually with API gravity less than about 18°. May have sand content of 50%.
