دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: see air-cooled exchanger. aerial river crossing n: a river crossing technique in which a pipeline is either suspended by cables over a waterway or attached to the girders of a bridge designed to carry vehicular traffic.

n: in pipeline construction, a cylindrical device fitted on both ends with hollow cutting teeth, used in directionally drilled river crossings. Used during the p111- back portion of a crossing effort, the barrel reamer opens the hole and keeps the pull on course.

n: a waterway crossing in which pipeline construction techniques similar to those on land are used. In a conventional crossing, the route is graded and ditched;the pipe is welded, tested, and pulled across the stream;and then the pipe is tied in on each side to the cross-country line.

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: in pipeline construction, the means by which a river crossing stays on course. Frequently computerised, guidance systems may be based on information gathered by pendulums, which determine inclination;gyroprobes, which are sensitive to drift and bearing;and sonar. Lasers are also used to guide crossing.

n: in pipeline construction. the hole drilled as the first step of a directionally drilled river crossing. It establishes a pathway for the pipeline.

n: a small-diameter hole that is later opened up to the required diameter. Sometimes used in directional drilling to control wellbore deviation during kick-off.

a small (sometimes) diameter hole drilled through a pay zone to determine the pay top and bottom or various contacts, before the main well position is selected. May also use a pilot hole to better control influx rate.

n: a type of special pipeline construction used when a pipeline must cross a river or stream. Tyes of river crossings include aerial crossings, conventional crossings, and directionally drilled crossings.

n: in pipe laying, a type of trenching machine used on river crossings when the channel cannot be diverted or when the volume of material to be removed is large. A suction pump rapidly forces large amounts of soil into a discharge pipe for deposit on the adjacent bank. A cutterhead can also be used on a suction dredge.

n: a collective term for the construction tasks bypassed by regular crews on pipeline construction. Tie-in includes welding road and river crossings, valves, portions of the pipeline left disconnected for hydrostatic testing, and other fabrication assemblies, as well as taping and coating the welds.

n: 1. in drilling, the string of drill pipe or tubing suspended in a well to which is attached a special tool or device that is used to carry out a certain task, such as squeeze cementing or fishing. 2. in pipe- line construction, the string of washpipe that replaces the pilot string in a directionally drilled river crossing. The work string remains in place under the river until the actual pipeline is made up and is ready to be pulled back across the river.

The drill pipe or tubing string with special tool ,which can fishing, snubbing cementing,etc.






a special, often large string of tubulars that are used during the completion of the well. Usually higher pressure capacity or allow higher weights than the production tubing.