دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: thin-walled pipe of high tensile strength with a diameter of 20 inches (51 centimetres) or more.

n: the state of having rigidity but little tensile strength. Compare toughness.

n: a casing string with joints of various collapse resistance, internal yield strength, and tensile strength, designed for various depths in a specific well to best withstand the conditions of that well. In deep wens, high tensile strength is required in the top casing joints to carry the load, whereas high collapse resistance and internal yield strength are needed in the bottom joints. In the middle of the casing, average quality is usually sufficient. The most suitable combination of types and weights of pipe helps to ensure efficient production at a minimum cost.

n: A casing string made up of various different grades or weights of casing (sometimes referred to as a tapered string).

n: the tendency of material such as a metal to break under repeated cyclic loading at a stress considerably less than the tensile strength shown in a static test.

a metal failure based on weakening by flexing or cycling. The material often work hardens.

n: most present-day seamless drill pipe falls into one of four American Petroleum Institute (API) grades. (1) E-75, with a minimum yield strength of 75,000 psi (517,125 kilopascals-kPa),a maximum yield strength of 105,000 psi (723,975 kPa),and a minimum tensile strength of 100,000 psi (689,500 kPa);(2) X- 95, with a minimum yield strength of 95,000 psi (655,025 kPa),a maximum yield strength of 125,000 psi (861,875 kPa),and a minimum tensile strength of 105,000 psi (723,975 kPa);(3) G-105, with a minimum yield strength of 105,000 psi (723,975 kPa),a maximum yield strength of 135,000 psi (930,825 kPa),and a minimum tensile strength of 115,000 psi (792,925 kPa);and S-135, with a minimum yield strength of 135,000 psi (930,825 kPa),a maximum yield strength of 165,000 psi (1,137,675 kPa),and a minimum tensile strength of 145,000 psi (999,775 kPa). V-150 is a non- API, but higher strength, grade. It has a minimum yield strength and a tensile strength of 150,000 psi (1,034,250 kPa).

n: drill pipe that is like conventional drill pipe except that it is manufactured with a thicker wall, which increases its weight and tensile strength. For example. five-inch lEU grade E75 standardweight drill pipe weighs 19.5 pounds per foot (29 kilograms per metre). while five- inch lEU grade E75 heavyweight drill pipe weighs 25.ro pounds per foot (38.4 kilograms per metre). Heavyweight drill pipe is placed in the top of the string to support a very long string of pipe. Heavyweight drill pipe may be used in the drill stem when high-tensile strength drill pipe is required hit high-grade steel cannot be used because of the highgrade steels susceptibility to hydrogen embrittlernent, which is a form of corrosion caused by hydrogen sulphide. Compare heavy- walled drill pipe.

n: thick -walled drill pipe used in directional drilling and placed between the drill collar and drill pipe.

n: the greatest longitudinal stress that a metal can bear without tearing apart. A metals tensile strength is greater than its yield strength.

the greatest lengthwise stress that a substance can bear without failure.

n: The maximum tensile strength that rock can be resisted.

n: drill pipe made from a metal alloy containing a large amount of titanium. Even though it is more expensive, titanium drill pipe is much stronger (has a higher tensile strength) than conventional steel pipe. Further, in horizontal drilling applications, titanium is almost twice as flexible as steel, which means that titanium pipe can be bent more than conventional pipe without being permanently deformed.

n: the maximum stress that a solid can withstand without undergoing permanent deformation either by plastic flow or by rupture. See tensile strength.