دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

in a horizontal plane, it is the angle (measured clockwise) of well path departure usually from true or magnetic north. It may also be expressed as the compass direction of the path of the well bore as measured by a borehole survey. (Note: check the speci

n: a map that shows the isogonic lines joining points of magnetic declination, which is the variation between magnetic north and true north. For example, in Los Angeles, California, when the compass needle is pointing toward north, true north actually lies 150 east of magnetic north. See declination.

n: th angle between true north and magnetic north,this varies with geographical location, and also changes slightly each year.

n: a surveying instrument that provide a serious of phtographic disc showing the derection by means of a magnetic compass, and so direction is referened to magnetic north.

n: the northerly direction in the earths magnetic field indicated by the needle of a magnetic compass.

n: the northerlydirection in the earths magnetic field indicated by the needle of a magnetic field.

n: The angle between the direction of magnetic north and the direction of tool face is called magnetic tool face orientation;the angle between the direction of high-edge of bore hole and the direction of tool face is called high-edge tool face orientation.