دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: an expression of the vertical height of the formation yielding hydrocarbons in commercial amounts.

pemature valve closure.

n: a special type of diamond drilling bit that does not use roller cones. Instead, polycrystalline diamond inserts are embedded into a matrix on the bit. PDC bits are often used to drill very hard, abrasive formations, but also find use in drilling medium and soft formations.

n: a type of drag bit that used small disc of man-made diamond as the cutting surface.

n: an organic material that forms by the partial decomposition and disintegration of vegetation in tropical swamps and other wet, humid areas. It is believed to be the precursor of coal.

a organic deposit, which, with time and burial stresses would become coal.

n: a wedge or spherical-shaped end of a hammer head, which is usually opposite a flat face on the head. v: to enlarge, straighten, or smooth with a peen.

n: an analog model of three dimensions used to study the structure and stratigraphy of a subsurface area. It is made by placing pegs of varying heights into a flat platform to represent the structural contours of strata.

n: a bottomhole assembly composed of a bit and several large-diameter drill collars and stabilisers placed to allow the bottom drill collar to bend toward the vertical. The assembly works on the principle of the pendulum effect and is used to decrease drift angle. See pendulum effect.

n: a BHA (q.v.) that is designed to drop angle by allowing the drill collars towards the low side of the hole.

n: the tendency of the drill stem bit, drill collars, drill pipe, and kelly-to hang in a vertical position due to the force of gravity.

n: the phenomenon that the drilling string tends to vertical under the gravity force.

n: the grivity foce under the cut point of pipe string in slop well produces a component force along the oritation of vertical of wall, which obliges the bit to break the rock in lower direction and makes the holebore recover its vertical condition, that fo

n: a special vehicle designed to allow control of a perforating operation within it.