دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a pressure test of a subsea blowout preventer stack performed on the rig floor on a test stump-a device that allows pressure to be exerted on the stackto ensure that all the pressure-sealing elements of the stack are working properly.

n: an irregular surface, generally parallel to a depositional layer, in which small, toothlike projections on one side of the surface fit into cavities of complementary shape on the other surface.

a pressure dissolution feature in a layered reservoir, often a vertical permeability barrier.

n: a short, threaded piece of pipe used to adapt parts of the drilling string that cannot otherwise be screwed together because of differences in thread size or design. A sub (i.e., a substitute) may also perform a special function. Lifting subs are used with drill collars to provide a shoulder to fit the drill pipe elevators;a kelly saver sub is placed between the drill pipe and the kelly to prevent excessive thread wear of the kelly and drill pipe threads;a bent sub is used when drilling a directional hole.

n: A shot section of pipe ,tubing ,or drill pipe run into a hole.

a short section of pipe, used to describe tools or to solve space-out gaps.

n: a small attachment on the rod-transfer equipment that picks up the rods after they are unscrewed from the string and then transfers them to the rod hanger, or reverses the procedure when going into the hole. See rod-transfer equipment.

the sinking of an oceanic plate edge as a result of collision of a less dense plate.

n: a deep trench formed in the ocean floor along the line of convergence of oceanic crust with other oceanic or continental crust when one plate (always oceanic) dives beneath the other. The plate that descends into the hot mantle is partially melted. Magma rises through fissures in the heavier, unmelted crust above, creating a line of plutons and volcanoes that eventually form an island arc parallel to the trench.

n: a map of the formations directly above an unconformity. Also called a worms-eye map.

the process by which matter passes passed from a solid directly to a gaseous state.