دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a deviation of natural gas from Boyles and Charless laws for ideal gas. Natural gas is not an ideal gas in that it is a mixture of several gases. As the pressure increases, the volume of space that a given weight of natural gas would occupy becomes increasingly smaller than the volume calculated by application of Boyles and Charless laws.

n: a tanker with a capacity over 100,000 deadweight tons (90,720 dead weight tonnes). Supertankers with a capacity larger than 100,000 deadweight tons but less than 500,000 deadweight tons (45,360 deadweight tonnes) are called very large crude carriers. Those with a capacity over 500,000 deadweight tons are called ultralarge crude carriers.

a safety valve controlled from the surface through hydraulic or electrical power.

n: Named as opening out of lattice,too.The phenomenon of the volume of clay increase,because its lattice absorb monomolecular water.

n: the first string of casing (after the conductor pipe) that is set in a well. It varies in length from a few hundred to several thousand feet (metres). Some states require a minimum length to protect freshwater sands. Compare conductor pipe.

n: A large-diameter, relatively low-pressure pipe string set in shallow yet competent formations for several reasons. First, the surface casing protects fresh-water aquifers onshore. Second, the surface casing provides minimal pressure integrity, and thus en

n: a valve, mounted in the Christmas tree assembly, that stops the flow of fluids from the well if damage occurs to the assembly.

n: in surface well testing, a temporary set of valves installed for flow control on a wellhead with no Christmas tree.

n: a telemetry instrument used in the surveying of a directional well. A downhole sensing unit records directional data, which are converted into signal pulses and then transmitted uphole, via conducting wireline or through the drilling fluid, to a monitor. See downhole telemetry.

n: a drilling mud prepared by adding a surfactant to a water-base mud to change the colloidal state of the clay from that of complete dispersion to one of controlled flocculation. Such muds were originally designed for use in deep, hightemperature wells, but their many advantages (high chemical and thermal stability, minimum swelling effect on claybearing zones, lower plastic viscosity, and so on) extend their applicability.

n: see surge valve.