دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: 1. the ratio of the weight of a given volume of a substance at a given temperature to the weight of an equal volume of a standard substance at the same temperature. For example, if 1 cubic inch of water at 39�F (3.9�C) weighs 1 unit and 1 cubic inch of another solid or liquid at 39�F weighs 0.95 unit. then the relative density of the substance is 0.95. In determin- ing the relative density of gases, the comparison is made with the standard of air or hydrogen. 2. the ratio of the mass of a given volume of a substance to the mass of a like volume of a standard substance, such as water or air.

n: the slight increase in mud weight used to offset friction losses that occur as the mud is circulated through the riser in a subsea blowout preventer system.

result of impacting one or more potential outcomes from an uncertainty assessment with risk. Risks might take the form of specific losses (i.e., costs),the impact of the failure (failure to achieve a goal),or other representation. Risk weighting is expr

n: an instrument used to indicate flow rate. It consists of a float in a tapered tube, or a tapered float that moves in a fixed orifice. Row passing around an annular space between the float and its container causes the float to rise until its weight counterbalances the pressure drop across it. rotary n: the machine used to impart rota- tional power to the drill stem while permitting vertical movement of the pipe for rotary drilling. Modern rotary machines have a special component, the rotary or master bushing, to turn the kelly bushing, which permits vertical movement of the kelly while the stem is turning.

n: It drive the drill string rotate through kelly,and carry the weight of drill string and casing .

n: a sealing device used to close off the annular space around the kelly in drilling with pressure at the surface, usually installed above the main blowout preventers. A rotating head makes it possible to drill ahead even when there is pressure in the annulus that the weight of the drilling fluid is not overcoming;the head prevents the well from blowing out. It is used mainly in the drilling of formations that have low permeability. The rate of penetration through such formations is usually rapid.

n: The equipment be used to seal the annular space around the kelly in the drilling process.

a circulating connection that allows pipe rotation. Used in cementing with non top-drive rigs.

n: the center bearing on a conventional walking beam pumping unit. It is mounted on top of the samson post. saddle clamp n: see clamp.

n: The weighted bearing that be used to support the saddle.

a bearing that allows the walking beam to move atop the Sampson post in a beam lift pump.

the derating factor applied to a pressure test limit or weight limit to set a maximum operating load condition.

n: a measurement of load safety for wire rope obtained by using the following formula: Factor of safety = B/W where- B = nominal catalog breaking strength of the wire rope, and W = calculated total static load. Also called design factor of wire rope.

n: The ratio of the dead weight to the breaking strength of the wire rope .

n: see wire-wrapped screen. screw packer n: a packer in which the packing element is expanded by rotating the pipe. It is used when it is not desirable to put tubing weight on the packer. scrub v: to remove certain constituents of a gas by passing it through a scrubber in which the gas is intimately mixed with a suitable liquid that absorbs or washes out the constituent to be removed.

n: The serial casing with mesh,which be situated at the bottom of oil string.