دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a written agreement that can be enforced by law and that lists the terms under which the acts required are to be performed. A drilling contract covers such factors as the cost of drilling the well (whether by the foot or by the day),the distribution of expenses between operator and contractor, and the type of equipment to be used.

n: an electric device used for governing the power that goes to an apparatus to which it is connected.

n: the pressure at a given temperature for a hydrocarbon system of fixed composition at which the vapourliquid equilibrium values of the various components in the system become or tend to become unified. The convergence pressure is used to adjust vapour-liquid equilibrium values to the particular system under consideration. conversion n: the change in the chemistry of a mud from one type to another. Reasons for making a conversion may be (1) to maintain a stable well bore, (2) to provide a mud that will tolerate higher weight, or density, (3) to drill soluble formations, or (4) to protect producing zones. Also called a breakover.

n: a tubular device, usually from 10 to 60 feet (3 to 18 metres) long, run at the bottom of the drill pipe in place of a bit and used to cut a core sample.

n: A special tool installed at the bottom of the drill string to cut and retain a core sample that is then recovered when the string is pulled out of the hole.

a barrel in the drilling BHA with a coring head designed to receive a rock core cut as part of core sampling operations.

n: The ratio between the actual length of core and cored footage.

n: The method that sustaining piece of core to prevent core stuck and decrease erosion with local reversal circulation in order to improve core recovery when core drilling in hard and brittle formation.

n: the buckling of tubing in a large-diameter pipe or casing.

compressional deformation of tubulars to the point where the tubing resembles a corkscrew. The condition may be temporary if the metal is not yielded past the elastic recovery point. Tubulars that are corkscrewed may be pumped through but will stick most

n: the measurement from the top of a pipeline to the top of the soil used to cover the pipeline along a right-of-way. Ditch depth and cover requirements are regulated by the US Department of Transportation.

n: a type of packer developed both an oil and a gas zone, with the gas zone on the bottom.

n pi: requirements, usually set by a regulatory agency, concerning the characteristics and manner of covering a pipeline.