دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: in a top drive, the power and spinning wrenches built into the unit that spins, makes up, breaks out, and backs up the pipe. See top drive.

n: the main device of top drived drilling system.

n: material applied on top of pipeline coating to protect the coating from damage. Materials used for wrapping include felt, fiberglass, fiberglass-reinforced felt, and kraft paper.

n: an increase in the average level of mud maintained in each of the mud pits, or tanks. If no mud or other substances have been added to the mud circulating in the well, then a pit gain is an indication that formation fluids have entered the well and that a kick has occurred.

n: when drilling belt of transition or high pressure , the fluid in layer equivalent displaces the fluid in the annular, thus arises the volume of mud pool increasing.

Extremely localized attack that results in holes in the metal. Will accelerate after start.

n: a phenomenon in which a decrease in the diameter of the borehole occurs because a plastic substance, such as salt, is being drilled. Since the temperature of the salt is higher than normal for a given depth (high temperature causes the salt to expand) and since mud weight is usually decreased when drilling such formations to maintain high penetration rates (thus decreasing the hydrostatic pressure exerted on the salt),the section of borehole in the salt zone can expand and possibly stick the drill stem. Also called salt squeeze.

n: Permanent mechanical or physical alteration that does not include rupture. Plastic deformation of rocks typically occurs at high temperatures and pressures, conditions under which rocks become relatively viscous.

a stress level, beyond the elastic limit, that produces yielding in tubulars.

n pi: movement of great crustal plates of the earth on slow currents in the plastic mantle, similar to the movement of boxes on a conveyor belt. Today geologists believe that the earths crust is divided into six major plates and several smaller ones atop some of which the continents are carried away from a system of mklocean ridges and toward another system of deep-sea trenches. The theory of plate tectonics explains most of the mysteries that confounded earlier geologists. Compare continental drift.

n: an immobile offshore structure from which development wells are drilled and produced. Platform rigs may be built of steel or concrete and may be rigid or compliant. Rigid platform rigs, which rest on the seafloor, are the caisson- type platform, the concrete gravity platform, and the steeljacket platform. Compliant platform rigs, which are used in deeper waters and yield to water and wind movements, are the guyedtower plat- form, the tension-leg platform, and the compliant piled tower platform.

production logging tool.