دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

v: to enlarge the wellbore below the casing.

n: To enlarge a wellbore past its original drilled size. Underreaming is sometimes done for safety or efficiency reasons. Some well planners believe it is safer to drill unknown shallow formations with a small-diameter bit, and if no gas is encountered, to t

n: see circulation valve. unloading a well n: removing fluid from the tubing in a well, often by means of a swab, to lower the bottomhole pressure in the wellbore at the perforations and induce the well to flow.

n: an imaginary line at right angles to the plane of the horizon. adj: of a wellbore, straight, not deviated.

n: The vertical profile of wellbore of directional well,which can display the measured depth ,vertical depth ,deviation angle and horizontal displacement.

vertical seismic profile> Run in a single wellbore. Helps correlate logs with seismic data.

placement of a fluid in the wellbore with coiled tubing where the fluid is spotted at the bottom of the zone and the CT is withdrawn at the same rate the hole is filled.

n: a device used in fishing for drill pipe. If the upper end of the lost pipe is leaning against the side of the wellbore, the wall hook centers it in the hole so that it may be recovered with an overshot, which is run on the fishing string and attached to the wall hook.

n: A fishing assistant tool be used to fish the lost drill string ,which can help to centralizing the drill string .

a device at the bottom of an overshot for centering the upward looking end of pipe that may be laying against the casing. The hook may resemble a finger or strip of metal pointing clockwise and used with pipe rotation to surround and center the pipe.

n: see differential sticking.

n: A condition whereby the drillstring cannot be moved (rotated or reciprocated) along the axis of the wellbore. Differential sticking typically occurs when high-contact forces caused by low reservoir pressures, high wellbore pressures, or both, are exerted

n: 1. excessive wellbore enlargement caused by solvent and erosional action of the drilling fluid. 2. a fluidcut opening caused by fluid leakage.

an enlarged area of the wellbore caused by removal of formation grains during drilling or circulation.