دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

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 wellbore intentionally drilled at an angle from the vertical. See directional drilling.

n: During the process of drilling,the direction of deflection and the axis figure go forward according to anticipated design.

n: a logging method that records drift angle, or deflection from the vertical, and direction of the drift. A singleshot directional-survey instrument makes a single photograph of a compass reading of the drift direction and the number of degrees the hole is off vertical. A multi shot survey instrument obtains numerous readings in the hole as the device is pulled out of the well. See directional drilling.

n: A method of measuring the inclination and direction of the wellbore by using a downhole instrument. The well must be surveyed at regular intervals to plot its course accurately.

a measurement of the well path that records the inclination and azimuth of the wellbore using a compass or other device.

n: a tool that, when lowered into the wellbore, makes a photographic record of the angle and drift of the wellbore;that is, it records the number of degrees the hole is off vertical and the direction in which it is off vertical. Several types of instrument are available;some are capable of photographing only a single record - single-shot survey instrumentswhereas others are capable of making several records in one run - multishot survey instruments.

n: the extended part at the cutting-blowoff piont of the screen frame
on vibrator

n: on a mud pump, the valve that opens to allow mud to be pushed out of the pump (discharged) by the pistons moving in the liners.

n: the valve used to control the up/down of drill fluid

n: the total calculated volume (TCV) by vessel measurement on arrival, less remaining on board (ROB),divided by the TCV by shore measurement at discharge.

n: an interruption in sedimentation caused by erosion;the strata above and below the disconformity are parallel. See unconformity. Compare nonconformity.

a change in the formation that may have been caused by ancient erosional forces. Accounts for variances in formation tops in near-by offset wells in a formation with no pay inclination.

n: taking account of future value in present calculations, i.e., determining present value of future dollars. Discounting is compounding in reverse.