دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: 1. in directional drilling, the direction of the wellbore or of the face of a deflection tool in degrees (0-359") clockwise from true north. 2. an arc of the horizon measured between a fixed point (such as true north) and the vertical circle passing through the centre of an object.

n: Reflecting the direction of wellbore deflection.

n: a device made up in the drill string that causes the bit to drill at an angle to the existing hole. It is often called a kickoff tool. because it is used at the kick-off point to start building angle.

n: See kickover tool.

n:1. intentional deviation of a wellbore from the vertical. Although well bores are normally drilled vertically, it is sometimes necessary or advantageous to drill at an angle from the vertical. Controlled directional drilling makes it possible to reach subsurface areas laterally remote from the point where the bit enters the earth. It often involves the use of deflection tools. 2. a technique of river crossing in pipeline construction in which the pipe is buried under the riverbed at very much greater than those of conventional crossings. With this technique, a hole in the form of an inverted arc is drilled beneath the river, and the made-up pipeline is pulled through it.

n: The intentional deviation of a wellbore in order to reach an objective some distance from the rig.

drilling the wellbore in a planned angle of deviation or trajectory.

n: a drilling tool made up in the drill string directly above the bit. It causes the bit to turn while the drill string remains fixed. It is used most often as a deflection tool in directional drilling, where it is made up between the bit and a bent sub (or, sometimes, the housing of the motor itself is bent). Two principal types of down-hole motor are the positive-displacement motor and the downhole turbine motor. Also called mud motor.

n: A special tool mounted in the BHA (q.v.) to drive the bit without rotating the drill string from surface (see positive displacement motor).

n: see deflection tool.

n: a deflection tool, placed above the drill bit in the drill stem. with a ball and socket arrangement that allows the tool to be deflected at an angle;used in directional drilling. It is useful in fishing operations because it allows the fishing tool to be deflected to the side of the hole, where a fish may have come to rest.

n: deflecting tool, it is also used in the fishing .

a flex joint in a tool string that allows alignment with a target not in the same plane.

n: the process of positioning a deflection tool so that it faces in the direction necessary to achieve the desired direction and drift angle for a directional hole.

n: the process by which a deflection tool is correctly positioned to achieve the intended direction and inclination of the wellbore.

n: a device used by directional drillers to determine which way to turn deflection tools to get the desired drift angle in a hole. This device comprises a protractor and various straight-edged scales that pivot around the protractor to figure the drift angle.

n: a device used to calculate the required orientation of a deflection tool.

n: an electronic device in which a probe is inserted into the drill stem near a directional drilling deflection tool. The probe sends continuous signals to the surface that show the direction and angle at which the bit is drilling. Readout devices greatly simplify accurate orientation of the drilling assembly so that a number of directional surveys can be eliminated. See directional drilling.

n: the part of a deflection toolusually marked with a scribe line-that is oriented in a particular direction to make a predetermined deflection of the wellbore.

n: The perpendicular plane along the direction of application of kickover tool.