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: any system or method by which surveillance is maintained on the position of a floating offshore drilling rig in relation to the subsea well-head when the rig is dynamically positioned. The rig should always be directly over the wellhead to minimize wear on subsea equipment and to facilitate operations involved with the equipment. See acoustic position reference. tau/line positionreference system.

n: a system for monitoring the position of a floating offshore drilling rig in relation to the subsea wellhead. A taut steel line is stretched from the rig to the ocean floor. An inclinometer measures the slope of the line at the rig, and, because the line is assumed to have been straight when stretched from the rig to the ocean floor, any angle in the line indicates that the rig has moved. The systems weakness is that the tautline can be distorted by currents and thus give inaccurate readings. Compare acoustic position reference, position-reference system.