دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: the cutting or boring element used in drilling oil and gas wells. The bit consists of a cutting element and a circulating element. The cutting element is steel teeth, tungsten carbide buttons, industrial diamonds, or polycrystalline diamonds (PDCs). The circulating element permits the passage of drilling fluid and utilises the hydraulic force of the fluid stream to improve drilling rates. In rotary drilling, several drill collars are joined to the bottom end of the drill pipe column, and the bit is attached to the end of the drill collars.

a drill bit, commonly either a roller cone, button bit, PDC, diamond or drag bit, used with a rotary string or a mud motor to drill through rock.

n pi: see captive customers. core cutter head n: the cutting element of the core barrel assembly. In design it corresponds to one of the three main types of bits: drag bits with blades for cutting soft formations;roller bits with rotating cutters for cutting medium-hard formations;and diamond bits for cutting very hard formations.

n: The drill bit whose stepped appearance blades are set with diamond.

n: The drag bit whose end is conical contour or rhombus.

n: any of a variety of drilling bits that have no moving parts. As they are rotated on bottom, elements of the bit make hole by being pressed into the formation and being dragged across it. See fishtail bit.

n: A drilling bit that has no cones or bearings but consists of a single unit with a cutting structure and circulation passageways. The fishtail bit was an early example of a drag bit, but is no longer in common use. Diamond bits are also drag bits.

n: a drilling bit with cutting edges of hard alloys. Developed about 1900, and first used with the rotary system of drilling, it is still useful . drilling very soft formations. Also called drag bit

n: the balde bit whose wings shape seem like fish tail

a drag bit with no moving parts, rotated like a conventional metal drilling bit.

n: refer to four-way drag bit

n: drag bit,with facing alloy, which have cutouts in the bottom of four fins

n: a drag bit with four blades. See bit. fishtail bit.

n: drag bit with blade which is used to break formation with four.