دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a special device that fits into a bit breaker adapter (a plate that goes into the rotary table) and conforms to the shape of the bit. Rig workers place the bit to be made up or broken out of the drill stem into the bit breaker and lock the rotary table to hold the bit breaker and bit stationary so that they can tighten or loosen the bit.

a heavy plate that can hold the bit in the rotary table to make or break it from the drill string.

n: jamming or wedging of the drill string in the borehole by sand or shale that is driven uphole by formation fluids during a blowout.

n: a device made up in the drill stem above the mill to collect bits of junk ground away during a milling operation. During milling, drilling mud under high pressure forces bits of junk up the narrow space between the boot sub and hole wall. When the junk reaches the wider annulus above the boot sub and pressure drops slightly, the junk falls into the boot sub. A boot sub also can be run above the bit during routine drilling to collect small pieces of junk that may damage the bit or interfere with its operation. Also called a junk sub or junk boot.

a device run in the drill string just above the mill to catch cuttings.

the equipment or tools at the bottom of the tubing or drill string. The BHA is changed to achieve a certain result.

n: The part of the drill string that is below the drill pipe. It usually consists of drill collars, stabilizers and various other components.

the main device for stopping the travel of the drawworks of a rig when running or pulling a drill string.

to separate the stands into single joints.

n: a special well-control tool made up in the drill pipe usually just above bubble, of gas enter the annulus, the bubble chopper allows mud in the drill string to be diverted into the gas bubble by means of an opening, or port, in the tool. The mud from the drill string mixes with and spreads out the large gas bubble so that the gas cannot expand to a great extent as it nears the surface. Reducing the amount of bubble expansion reduces pressure on the casing near the surface and thus minimises the chances of formation fracture and an underground blowout.

n: The inferior drill column bend since bit load produced by self-weight reach to definite value when drill column is in the wellbore. It is decided by bit load and deviation angle.

n: a device made up in the drill string that, when actuated, de- livers a heavy downward blow to the string. A bumper jar has a hollow body that moves upward when the drill string is picked up. When the string is dropped quickly, the jar body produces a sharp downward blow on the tubing or pipe made up below the jar. If downward blows can free a fish, a bumper jar can be very effective.

n: Made by upwardness, lower part of the body and joint. The upwardness and lower part of the body are connected with plain bearing. The operating principle of it is the same with bumper sub. Used to handle sticking when the drill bit is not at the bottom.