دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a system consisting of a beacon positioned on the seafloor to transmit an acoustic signal, a set of three or four hydrophones mounted on the hull of a floating offshore drilling vessel to receive the signal, and a position display unit to track the relative positions of the rig and the drill site. Monitoring of the display unit aids in accurate positioning of the rig over the site.

n: a warning device triggered by the presence of abnormal conditions in a machine or system. For example, a lowwater alarm automatically signals when the water level in a vessel falls below its preset minimum. Offshore, alarms are used to warn personnel of dangerous or unusual conditions, such as fires and escaping gases.

n: a device for increasing the magnitude of a quantity such as an electrical measurement signal. Amplifiers may be used to increase a transmitted and received measurement signal.

n: (am) modulation of the amplitude of a radio carrier wave in accordance with the strength of the audio or other signal. amplitudes n pi: shapes and heights of the peaks in a spontaneous potential curve.

n: the representation of the magnitude of a variable in the form of a measurable physical quantity that varies smoothly rather than in discrete steps.

a device in a perforating gun that signals through a delayed shot or sound that the detonating cord has fired to the bottom of a gun.

n: a record showing variations in wellbore diameter by depth, indicating undue enlargement due to caving in, washout, or other causes. The caliper log also reveals corrosion, scaling, or pitting inside tubular goods.

n: A tool run on wireline that measures the diameter of the wellbore. It may be used for detecting washouts, calculating cement volumes, or detecting internal corrosion of casing.

a recording of the diameter changes in a well made by a tool with mechanical arms that touch the wellbore or a sonic signal bouncing off the borehole wall.

a geological time from 500 million to 570 million years ago. Often signals the earliest hydrocarbon productive rocks.

n: an acoustic survey or sonic-logging method that records the quality or hardness of the cement used in the annulus to bond the casing and the formation. Casing that is well bonded to the formation transmits an acoustic signal quickly;poorly bonded causing transmits a signal slowly. See acoustic survey. acoustic well logging.

n: See cement bond log.

n: 1. a life-support system in which the gas is recycled continually while the carbon dioxide is removed and oxygen added periodically. 2. a television installation in which the signal is transmitted by wire to a limited number of receivers.